I need help with this 1989 Trans Am 5.7 TPI - STALLING!!!
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- Опубліковано 7 вер 2024
- This is a 1989 Pontiac Trans-Am GTA, with w 5.7 TPI engine.
It idles, when you put it in gear, it chokes and stalls.
It was running fine and started this suddenly and I can't figure it out!!!
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I'm not an "expert" on TA's, but i am a mechanic, and I have worked on several of these engines, and those in C4 Corvette's etc. The "surging" idle is a common-ish issue with the throttle position sensor.... or possibly even something feedback related like the o2 sensor..
First thing . Selling batteries.
Question was .
Grounds . And condition of them .
First thing corrosion goes for .
Purity
IAC motor on the Throttle body..... Clean and reset
Throttle Minimum Air Position
Tools needed:
1. Torx driver # T-20
2. Paper Clip
3. Small Punch
4. Tachometer
GENERAL NOTE: The engine should be at normal operating temperature before performing any adjustments. Never rely on the dash mounted instruments for diagnostics and adjustments. The oil pressure and temperature gauges and the voltmeter and tachometer just aren't calibrated accurately enough for diagnosis, but are a relative indication for monitoring the vehicle while driving.
For this adjustment, the transmission will be in DRIVE while you're under the hood. You will need to securely set the parking brake and block the drive wheels. It would also be a good idea to have an assistant hold the service brake while you perform the adjustments.
In order to successfully complete the adjustment, the IAC air passages and pintle need to be clean. The throttle plates and bores need to be clean as well. If this is not the case, you'll need to remove the air cleaner from TBI engines or the intake air bellows from TPI engines to gain access to the area to be cleaned. A spray-type carburetor cleaner works well for this. Cleaning the IAC passages on a TPI/MAF engine will set a DTC, but we'll be clearing that later. With the engine idling, direct the spray cleaner in to the IAC air passages and around the throttle plates. Shut off the engine and continue cleaning the throttle plates by opening the throttle manually. Once everything is satisfactorily cleaned, replace the air bellows on TPI engines. Many times, this alone can solve IAC/idle speed problems.
Cut and form a paper clip into a "U" shape. Insert the clip ends into the ALDL in the 'A' and 'B' sockets. Turn on the ignition, but don't start the engine. This will force the ECM into its diagnostic mode. Wait 30 seconds to allow the IAC pintle to fully extend. Under the hood, remove the electrical connector from the IAC, then turn off the ignition and remove the paper clip jumper from the ALDL. With the IAC pintle fully extended (closed) all idle air will be controlled by the position of the throttle plates.
Locate the Torx screw on the left side of the throttle body. It may be equipped with a protective metal cap from the factory. This was intended to discourage adjustment. If the cap is present, use a small punch to knock it out. Once the screw is accessible, start the engine and place the transmission in DRIVE. Adjust the throttle stop to obtain 450-500 RPM with the transmission in "DRIVE", rotating the Torx screw clockwise to raise speed and counter-clockwise to lower speed. Once the idle RPM is set, place the transmission in PARK and turn off the engine.
Re-connect the electrical connector onto the IAC. Start engine. Idle speed should be governed by the ECM at approximately 650 rpm in "DRIVE" (for unmodified cars). Idle speed in NEUTRAL or PARK is less significant, and will be higher.
Reinitializing the ECM
If you set a DTC during the procedure, the SES light should be illuminated on the dash. This ECM retains DTC data for the previous 50 engine starts, so the codes will eventually be cleared. If you want more immediate results, after shutting down the engine disconnect the negative battery terminal for five minutes. This will clear the ECM of all diagnostic trouble codes. Clearing the ECM also clears any data learned about your engine, and clears the radio presets. If you have a Delco-Loc or Theft Loc II radio, make sure you follow the procedure to unlock the radio protection before disconnecting the battery. This five minutes is also just about long enough to clean both battery cables. Reconnect the battery. When you first start the engine after clearing the ECM, the engine will operate with base parameters programmed into the ECM PROM. These parameters may not be optimum for your engine, but the ECM will enter a Block Learn Mode soon after the engine is warm and enters Closed Loop Mode. The ECM will write new data tables specific to your engine and will eventually rely on those tables instead of the base tables of the factory program. You can expedite this process by driving the car for 20 minutes under varying conditions to allow the ECM to initialize. Or you can wait and drive the car normally at your convenience. The BLM tables are constantly being updated as sensor input ranges change, but the greatest change will occur within the first twenty minutes of Closed Loop operation.
Might be worth calling the Car Wizard
Idle Air Control Valve is stuck or weak fuel pump/clogged fuel filter
Yes, I’m with Bernie I would be replacing the IAC. I had a similar issue with my TPI recently and this was the problem.
I agree with this.
Two words: car wizard
your IAC Idle Air Control Value may finally be failing. When you turn the AC on it moves to adjust the idle. When you put it in drive it adjusts the idle to compensate for the load under drive. Replace it. Also Carib clean the port that it goes into to clear out gunk build up before putting the new one in..
If your questioning this, hit the accelerator when the car is about to stumble and die which will over ride the IAC and up the RPMs to keep idel
Worst case is that your Torque Lock on the transmission is engaged and locked 1 to 1. Find the connector to the transmission and disconnect the torque lock and see if the engine stalls when in drive. If the Lock is engaged, then the engine will stall when putting it in drive cause the torque converter is not slipping. Had this happen on a 89 Caviler that drove us nuts until we did this..
It is your IAC , also check your fuel filter , and test your fuel pump at the rail to make sure you have enough pressure -
also spray brake clean around at vacuum areas , to see if idle raises it could be as easy as vacuum
Check the ignition module under the distributor and make sure that there's grease under it and none of the pins are burned. Had my 91 Z28 with L98 TPI do that. Could be the throttle position and/or idle are control valve.
I did several TPI swaps years ago and some were the early MAF sensor ones which I don't like. That idle issue is generally a bad IAC or one that needs to be relearned. There were also rare issues caused by EGR valves that could leak a little but at that low mileage I doubt that's an issue. The IAC is where I would start as that was a common issue on the TPI and a number of TBI engines as well. Very annoying to diagnose at times and also most likely since that idle is hunting.
I still have my 84 El Camino that I did an 86 MAF TPI swap into.
I agree that it may be a bad IAC. It should raise the idle when needed, and is probably not.
Do you smell any odors of Gas when it idles. ? If you do replace Vacuum controlled fuel Pressure Regulator under the plenum.
2nd repair is to adjust the TPS located on the front of the intake plenum on the pass.side 2 screws hold it in place.
I am working on an 89 Vette with the same problem. I Replaced the fuel Pressure regulator and car runs great,.
If you suspect a VAC leak spray 2+2 around the base of the intake ,manifold, and near vac canister. I do not think it is Vac leak. Because Engine RPM's at idle do not seem excessive.
Back in the day we had issues with the dist shaft magnet. Causing a stall at idle. We tested by disconnecting the brown /white timing wire. While disconnected start car use timing light. The timing should increase by about 6 degrees. While reving engine to 2000 rpm.If not replace dist shaft. I know it sounds crazy. I was a gm tech when that car was new.
TPS or IAC. I'd replace maf, map, and egr valve as well.
IAC: Jump A/B on the ALDL with a paper clip. Turn key to on position (don’t start). You’ll hear the IAC buzzing. Wait 30 seconds then unplug IAC. Unplug A/B jump. Start engine.
That’s the full IAC relearn. You have to do it any time the battery is disconnected (ECM is removed from power)
I’m leaning towards the Idle Air control valve going bad. Replace that and spray out the throttle body with Seafoam.
Had it happen to me on one of my TPI Trans Am’s.
I had the same issue with a ford.. IAC was bad and I had to leave in neutral when stopped. .Would stall when put in gear and not move.
Love them old 3rd gens... my father had 3 of them growing up.... got me into cars
IAC is where I would start as well. Im sure its running by now though. Lol love those cars. Ive had six. ‘87 Z28 now. My parents bought this one in 1989. It just died at 508K. Rod was knocking for close to 10 years. Insane. All highway of course. Put intake gaskets on it about 10 years ago. Thats it, other than maintenance. Factory QJet hasnt even been rebuilt(last year for carb. Not many sold)It was getting about 10mpg though lmao smoked like a freight train when it started. Probably no valve seals left at all. 😂
I’ve had a 87 and a 89 the small piece of rubber hose t from the fuel pump to the sending unit each on both Ta’s the hose had split but only way to tell was to turn key on with fuel pump out of the tank, cars would only stall out under a load
Bob 1 of a few things going on there, 1 the IAC might be giving you an issue, there is a reset procedure. 2 maybe a vacuum leak causing the IAC to not be able to go back or out fast enough. Smoke test the vacuum lines to see if thats the problem. 3 Ive seen TCC solenoid staying stuck open when in park then you go do drive it kills out the engine. Easy way to test that is to unplug it at the transmission and see what happens. I can already tell by the way the engine fires up and revs, everything is happy so you problem is gonna be kinda simple. Please reach out if i can help u
Did a quick google search and first thing it says is try changing the idle air control.
As a owner of many T/A's over the years and a former Vegas local , if it's happening after it heats up welcome to desert fuel vapor lock , you should only run a AC Delco or equal fuel pump , most others can't keep up with desert heat .
Charcoal canister and gas cap would be next on list to check
Good Lord @Bob… I hope you figure this out… I’m having the same exact problem with mine.. I’ve changed EVERYTHING except the motor itself!! Driving me bananas!!
Check fuel pressure before filter. My 82 camaro cross fire eould fire up and do that. Fuel pumps known go out. Mine would only stay running with my foot on accelotor. I thought i had vacuum leak, i even changed out my distributor. It was literally the last thing i checked.
I think i still have my videos of it on my channel.
Mine was the cross fire injection so. Yeaaah
Pull the IAC and see if its all gummed up inside the cavity it installs into, it could also be an ignition control module
Easy test on the MAS is let engine idle. Take a Screwdriver and tap the MAF with the handle of the Screwdriver, if engine idle goes bonkers, MAF is bad. Check grounds for ECM and make sure they are making good contact. Hope I helped.
Idle air control valve or vacuum leak mine did the same thing I replaced both it fixd it
One of the things Ive seen is the engine coolant temp sensor or throttle plates have closed over time.
Everything you replace has to be ac delco, that being said, you have the cap rotor plugs and wires. Then you have the test to see if the idle air control valve is operating and the engine is changing rpm from cold start to warming up along with sucking noise it makes. There is also a little eeprom in the ecu for 90's versions with tbi that goes bad and can cause no idle up or down. Then you have the map sensor that changes everything with vaccum sensing.
The possible wear on the throttle body causing it not to get enough air or stay at a rpm everything can function is a big one.
There should be a cap behind the screw that the throttle body rests on when it closes.
Its usually on the throttle cable side and all you will see is what looks like a screw
If you have that cap behind the resting screw on the throttle body, you can open up that cap and there should be a star screw you can adjust the air idle with.
Your other test for air is using a feeler gauge between that screw and the throttle body to see if it will run with restarting the engine and keeping that gap.
I had to adjust the screw on all 3 of my gm tbi vehicles.
Coolant temp sensor you can unplug and start with holding / adjusting throttle to see if its better.
But with everything I have experienced with that throttle fluctuation and stalling thing even after reseating all the valves and new head gaskets its best if you can get to that screw behind the cap and adjust that so its got enough air at idle.
The procedure to adjusting the screw once you get behind that cap is to mark it with a ink pen or something you will know where it was originally at.
Then you make small adjustments one at a time by turning the screw, tapping the throttle, turning it off starting it and then tapping the throttle again to see where the computer decides to set the rpm at.
I usually set them close to 1000 rpm and they will engage the transmission along with giving the motor a walk when you tap the throttle.
You will also get better gas mileage because the air will be more balanced to the fuel.
Hope this helps...
You also have the paper clip trick under the dash by jumping 2 wires and counting flashes for codes.
You can also loose the diaphragm in the egr valve causing it to not keep vaccum along with a bad pcv valve.
But the camaro I had with the 90s tbi had the same idle surge, dieing issue and a bad eeprom in the computer.
After I adjusted the hidden screw it was drivable with no issues.
My 87 firebird formula 5.0 tpi had a stalling issue and had no power. I disconnected the MAS and the car went in to limp mode and ran great. I replaced the MAS and it runs good. If it was a vacuum leak it would have a high idle. If it turns out to be the MAS buy the best one, don't cheap out you'll regret it.
Also try checking with Corvette experts. Same.engine. I had to take my 89 GTA to a corvette specialist to figure some of my issues that I was having with the chip/computer board. Make sure the wireing harness for the board doesnt have any bad connections or wires imtermittently losing connection.
Fuel pump may be going out another thing maybe the oil pressure sensor above the oil filter
And the blinker fluid capacitor
Those IACs are adjustable too it could be old and not moving as fast as it should
Just a suggestion based on age and mileage. Check the brake booster for a vacuum leak and remember it has a one way valve!
Check the IAC and also check and make sure the bearings in the AC compressor aren't worn. Sometimes when they wear it will stall the engine when the clutch engages. But my first guess would be the IAC valve or TPS. Hook up a scan tool and see what the MAF is reading when the stall occurs. May help may not but that's the places I would start if it was mine.
Edit: If you hook up a scanner it has to be OBDI compatible and may just give you a MAF code instead of actual data. So idk how much that help that would be. I forgot for a second about that engine being pre OBDII.
Yeah they are such a pain. Because my camaro would run, then when got past warm up cycle died out. If i had my foot on accelerators i could maintain rpms in like 4k range and then it would smother down. It was oddest thing it would do. Because of this weird behavior two years later in my spare time.. checking all sensors with multi meter..cutting a hole in my cat, replacing the pick up coil and distributor..new tune up...checked for vac leaks...checked the timing...checked the fuel canister out..literally the last simplest thing..and my gauge showed 0 psi. I thought my gauge was busted and it was only a 30 psi gauge. Long story short..I was pist as fuck.
Needs a idle relearn done after alternator was replaced. This style ECM must relearn idle after battery is disconnected!!!! I have been working on these cars since they were new! I have a 1987 Firebird Formula350.
Check your "mass air flow" sensor. You might just need to clean it, but make sure you use the correct cleaner for the MAF.
did that
@@RobertMoseley Could be the MAF went tits up. Also check your injectors if they are clogged with varnish, or even a bad injector.
There is a valve on the passenger side on the exhaust on the downpipe it is vacuum operated on my IROC Z28 89 this was not functioning properly and was closing when the engine warmed up therefore restricting all exhaust gas on that side of the engine causing it to stall
Pull the IAC valve and clean out the carbon buildup
If I had to take a guess I would say it is the idle air control valve. The check engine light on the older pre 1996 gm cars is designed to flash like that. OBDY2 didn't exist when that car was made so gm designed the check engine light to flash to tell you the problem with your engine. Count how many times the check engine light flashes and look it up on the internet to find the code and possible solutions to your problem. If you want to test the fuel pump you can hook up a a fuel pressure gauge on it, and check to see what the pressure is at idle with out the air conditioning on, at idle with the air conditioning on, and in drive, and that right there will tell you if that is bad. Also if you haven't changed the fuel filter yet go ahead and do that. I have not worked on an old fire bird like that, but I am pretty sure it's fuel injection system works just like any other multi port fuel injection system from the early 90s; with a mass air flow sensor to measure the air flowing through the throttle body, the idle air control valve to control the amount of air traveling through the throttle body at idle, throttle position sensor to tell the computer the position of the throttle plates and the position of the gas pedal, a crank sensor or oil pressure sensor to tell the computer if the engine is actively rotating and needs the fuel turn on, a engine temperature sensor to tell the computer the temperature of the engine so it can can calculate the right amount of fuel based on the temperature of the engine, and the oxygen sensors on the exhaust to check oxygen levels in the exhaust gasses before and after the catalytic converter. Also, just google the problem on the internet, there are a lot of different forums out there that will walk you through how to diagnose and fix the problem with your car. Go through and read a couple of them and that should point you in the right direction. Who knows that new alternator might be causing an issue.
Call the Car Wizard in Kansas! I have always been a big fan of you channel, I love seeing all the different cars, especially the Cadillacs. You are definitely a person I would like to meet some day for sure.😃
Daniel Zearfoss
Idle air control or throttle position sensor....I'm leaning towards the iac being toast
I agree with this assessment.
I had almost exact same thing happen on my Montero after I relaced the heads when putting back the Intake Air control valve on the Throttle Body I turned it in a different direction then I was supposed to be. Its seating bolts holes are elongated for adjustment purposes. It idled at around 950-1200 warm and every time it goes into drive or reverse the engine would rev up a crazy bunch and either die or go to very low rpm. When i went to adjust it in the other direction I pushed it too much the lther way and it just kept ding instantly like this. You need to find the sweet spot and if you have a motor in the throttle body you have to calibrate it so it doesnt mess up while shifting gears in between the shifts it. If mis ajdusted by a notch it can rev up between gears like the trans is slpping
Possible Clogged catalytic converter. I have the Z28 version of your car. My car was fine then a tank of bad gas or gas with a lot of detergent clogged most of the little squares in the cat.
How to replace the mass air flow sensor. Thats what my car was doing. After I replaced it worked like new agian.
My 85 Vette had that issue. It needed a fresh Idle Air Control valve. Around 12 bucks on Ebay.
Check the AC clutch for high amperage, if high it will drop the voltage and stall the engine.
The engine coolant temperature sensor for the computer could be the culprit it controls the fuel mixture based on the engine temperature along with the maf sensor. The iac valve being bad and the holes in the throttle body where it mounts could also be carbon coated not allowing it to set correct idle. The tps seems to be working correctly or the engine rpm wouldn't change as it does.
My 89 Camaro had a similar issue. It was a dirty and plugged up IAC valve and eventually the MAF had to be replaced.
After seeing the comments, I lean towards the smoke check on the vac system. Yea the IAC will look like crap after 30+ years of use. I have a 90 vett L98. 5.7. I know it's not the same in some ways, such as vacuum line routing, MAF location, but There is a vacuum line that splits into two going to the EGR solenoid right behind where you changed out the alternator. Mine was damaged when the intake was removed due to an oil leak in the rear. I think it was cracked before but dammed if I could find the leak. Due to my idle issues before and after the gasket reseal job. 3 EGR valves later. Delco, and standard won't hold PSI. #3 held!!! easy check. Disco the vac line on the EGR or put a T in the line and check the Vac. it should hold 20 Vac. for more than 5 min.s. I replaced mind when the intake was off along with the air sensor. The new vac. solenoid turns out to also be cracked. I would have a shop smoke it for you, not because I like spending money. Because when your frustration level gets going. A fresh set of eyes can pick up what you miss. If you're going to replace the IAC. I would follow a UA-cam clip while doing so along with a shop manual if you have one. My ICA was nasty after 27.000 miles and wasn't seating well due to the one-sided grove in the plunger. Battery was disco and I didn't have a relearn issue. 30+ years on any rubber line is about 20 too many. With the heat cycles you have your Luckey the Radiator hoses haven spilt. My all looked great but 30+ years. If you want to see what I mean, just pull the rubber line going to PCV valve. Lightly squeeze the end and see if it's got cracks. I'm not saying the will completely fix the idle. But it's a start. I was at the same place as you with my Idle issues. 2 cracked parts were my issue. The vac Y fitting was old. The vac. sensor was new. GOOD LUCK Sir.
Because you had the battery disconnected the computer has to relearn the idle.
I’d recommend clean out the iac and throttle plate. Relearn the idle with a scan tool if you don’t have a scan tool you just drive it around and it will figure it out.
also for better performance get rid of the coolant going to the throttle body they sell a bypass kit or do it yourself you don't need 220 degrees at the throttle body its onle for cold weather areas
check your filter connections..
Check wires. Ground wires..... its amperage overload.... my 1988 gmc truck did that... and if I recall as well the ground on the gas pump.....
My friend new a way to scan it with the port under the dash and u look at the service engine light flashing and u count the flashes and look up the corrisponding code
I would start with the IAC but if you hold a little throttle in gear if it doesn't stall swap the IAC. The EGR would set a code but can cause it to stall.
1989 will have VATS so watch for the security light, but if you trip that you can't crank it immediately so not likely.
Try it with the gas cap off (from another video I know the thing is pulling a vacuum in the tank.
See if it stalls by pumping the brakes in park. That is the biggest vacuum draw, and you are like hitting the brake before putting it in gear. Putting that car in gear otherwise doesn't induce any vacuum use.
There is a vacuum valve in the AC controls that is notorious for breaking, but even that isn't enough to stall the car, nor is a blow actuator. However it is a single vacuum feed line for the ac so you could cap that off to test.
Oh one last thought. The fuel pump is a dual circuit. First is the ECU, drives a relay, turns on pump. Second is the oil pressure switch. If it is hard to start hot, then often the ECU circuit is bad and it's cranking long enough to trigger the oil switch circuit which will kick on the fuel pump. Many think the oil switch will kill the pump with now pressure but it is a parallel circuit not series. However if the ECU circuit is malfunctioning and the oil pressure dips it can stall. I would try putting a jumper on and bypassing the fuel pump relay beside the booster. This will cause the pump to run all the time, but then try putting it in gear.
Oh I've owned a 1989 firebird since 1997, I pulled the original engine and put in a 5.7 LS1 and T56 3 years ago. Build a custom harness. All gauges work, AC works, full emissions. So yeah I know these cars.
Haven't even watched it and I'm just gonna guess something with the ignition module.
Edit : Yeah, I remember hearing some weird story about something like this happening being caused by some little chip or thing in the distributor that's part of the ignition system. If I remember the story correctly it has something to do with the way the car is wired and is some weird common quirk on GM cars and trucks from that era. They're sensitive to heat and when they get old the thermal paste dries out and they essentially cook themselves to death.
I had a 91 firebird V6...would intermittently die at a stop light....would start right back up....no one could ever figure it out. It was OK and never did this until the factory battery crapped out. I had almost everything electrical replaced..
Pull the from code the dash light flashing codes
Amperage overload or maybe the fuel pump.
Idle air control
Check out the MAF sensor.
MAP sensor could be the problem
Mass Air Flow sensor
A WEAK spark or fuel supply can also cause that kind of stalling. The spark gets "blown out" so to speak, almost like a candle flame
Iac or fuel pressure bad
Fuel pump is on way out.getting gas but spitting.. fuel pumps like a battery. They don't last forever..
Idle Air Control valve dirty or non functioning .Sometimes doesn't set a code .
Video Bob I'm thinking it's your MAP sensor it's a little square box with a electric plug and two vacuum likes usually close to firewall ..
its a non MAP car.. it has a MAF
Iac valve most likely are mass airflow I know you cleaned it but usally once they go out you have to buy a new one that's oe
If getting a check engine light. Check for codes with code scanner
How many miles are on the car? is it the original transmission? Is it a stick or automatic transmission? If an automatic, when was the last time the transmission was serviced (fluid and filter changed)? A locked up torque converter can cause an engine to stall when shifting the transmission into gear. And that is exactly what's happening. As soon as you put it into drive it stalls. If it was anything else, it would stall, run rough, etc. while in park. From what I see and hear in the video, the engine is running great, even when the a/c has been turned on. The issue with the stall only happens when the transmission is shifted into gear. For that reason I would look at the torque converter.
Does it also go off if you turn the steering all the way to the left or right side? OBD? Fuel trims? Did you smoke test, clamp the hoses, umplug the MAF Sensor etc.?
Did you end up figuring this out? - Sam
Just seen a spot with your delorean and they were talking about the Alpha 5.
Where? Post link.
@@RobertMoseley Sorry it was on the tv during Barrett Jackson.
@@RobertMoseley What a suck..................turned the auction on @ 8pm here when it started airing today and the first lot they show was 761 WTF Barrett.
Smoke Test? Or I would look at Cam sensor
Nothing survives in that heat - probably a cooling issue not enough coolant flowing under a load may have a trip sensor - that’s a guess.
a/c on making it worse, points to the IAC valve.
It doesnt matter if you clean it maf if its bad u need a new one
Flux capacitor needs recharged
hummm will it stay running if you give it just a slight amount of gas if so i would check your idle air control valve see if it has stuck shut or failed very common failure on gm and the symptoms match where you put it in drive and the engine stalls I did notice the engine did not rpm up when you put the AC on to compensate for the load the same thing when you went into reverse it’s running too good for a vacuum leak but it still could be a vacuum leak I hate saying that but it’s true these cars even though they are pre-OBD 2 have data output if you can get a hold of a snapon that does obd1 strange that the check engine light is flickering on and off definitely makes it much more difficult im definitely thinking you have a faulty idle air control valve or it’s blocked or stuck it is possible this could be temperature related with a bad temperature sensor as well you can test this buy just unplugging the sensor and the car should default to a higher idol because the computer will think it’s cold outside gm usually used two sensors though so you gotta find the one that has control for the computer not the dash as they are different and not tied together done a lot of work on TBI 350s I hope this helps they’re not much different than the multi port fuel injection but i have not worked on much multiport fuel injected eights the method behind it those is similar to the tbi from the symptoms you have I really think you have a problem with the idle control circuit and it’s most common to be the control valve itself i look forward to here what you find is the problem and hope my comments could have helped in some way
The maf could also be bad if it hasn't been replaced.
Fuel pump may be fuel filter.
Idle air control valve may not be working properly.
Could you send me a picture of the vacuum hoses on the front passenger side? I have a 1989 GTA but a couple of the hoses are not connected.
Ever get those hoses sorted out?
@@aamantium1 Yes sir.
@@MichaelFunderburk good stuff. I was going to offer to send you some pics of a virtually untouched 89 GTA engine bay
@@aamantium1 Please do.
@@MichaelFunderburk give me a way to contact you and I can send you whatever you might need
I'm no expert on the Trans AM but I lived in Vegas before, one non engine thing to check but might do nothing to help, the cabin air filter. clog that enough it can put an unexpected vacuum on the AC system.
They don’t have a cabin air filter.
@@johnlanter9592 I did say I'm no expert ;)
Look! It's a bird! It's a plane! It's the Car Wizard !
AC clutch
Or compressor
Vacuum humm try the pop up light at the same time... but a cam would mess with vacuum. 1986 TA is my ride. But I had a few TBI systems. What I do is go back to carb
@@jimtuna1354 same problems. Some of the cars are build in Florida and the others in California. They all had issues if they came from California. And look up under the car for the gas pump ground. It forms a bit of rust under the connector and the frame. It's a common GM problem. We see it more up in Canada. But now every car or truck i buy from GM used it gets a new ground connection so i am not on the side of the road 400$ towing...
The cat? Had the same issue with mine.
Thats a common issue ans an easy fix.
Mass air flow. My 86 did the same thing and it would go out once a year for some reason.
Timing they have issues when not used enough. That and the internal rubber of the diphram goes out.
Mass air flow sensor i had a 88 iroc z same engine
Replace the MAF,happen to my Trans Am back in the day.
When u reved it something liquid is blowin out the drivers side ofthe motor
Thats just dust blowing…
Fuel pump.
Shhhhh let him figure it out
Clean the throttle body!!!!
That's weird Bob. I wished I good help man
Torque Converter
Throttle pacision senser
Change the computer in it my 88 trans am did the same thing