1993 Infiniti J30 Rough Running Diagnostic
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- Опубліковано 20 кві 2021
- Customer brought in this low mileage (101000) 1993 Infiniti J30 with a rough running issue that several shops could diagnose. Let me show you how I approached the situation.
Spoilers below this line........
Based on my test drive I was reasonably certain my issue wasn't a fuel supply issue from the pump or filter, wasn't plugged exhaust, wasn't engine mechanical, wasn't MAF sensor. Most of those things will effect all cylinders and I was feeling a roughness on just one or two cylinders. The roughness increased as the car warmed up. My first step after a drive around the block was to scan the vehicle. I was fortunate enough to have the old Nissan adaptor I needed and I was able to retrieve a code 51 - injector circuit open. This is where I would have been heading next because its a common issue on the Nissan's from the 90's. I used the guided component test meter in the Snapon triton D10 to get some information about the best place to test the injectors which led me to the two injector bulkheads under the hood near the back of the intake. I placed a low amp clamp set to a 20 amp scale around the power supply wire for all six injectors and notice one that didn't look like the others. Now we need a sync channel to find out which injector is failing. With my second channel connected to the control side(negative side) of the injector we identifies that cylinder 6 injector is the bad injector and the resistance is higher than normal causing low amperage draw.
I measure the resistance of injector number six after removed and it was 20 ohms cold and 33 ohms after a soak in 150F water. I didn't measure the other 5 but I did replace them. - Авто та транспорт
Nice diag, Chad! Looks like the other shops parts cannons would have been giant MISFIRES lol
So glad I found your channel! I have learned so much from your wave form lessons. As a DIYer I couldn’t always complete the homework , mostly because working outside on vehicles in Michigan winter not that much fun, but still learned from every episode using a Pico 2 channel scope. Now you have made your channel even more helpful by showing approaches on pre OBDII vintage which I still have in my family “fleet”. THANK YOU FOR ALL YOUR EFFORT!
Great channel... thanks. Looking forward to more of your videos.
Great quick diag Chad!
Awesome video. Awesome diag. Thanks for sharing
Great video
As an owner of a J30 with 55,000 orig miles I can honestly say these cars were overbuilt and when stuff goes wrong, it can be a pain to trace the cause of the issue. One time, my car sat for 2 months at a shop because they couldn't figure out its no-start issue. After two months of poking and prodding, my mechanic took a wild guess and replaced the coolant temp sensor. Just like that the car was fixed. These are fantastic cars when everything runs right but just be cautious should run across one for sale at a steal price. Some parts are becoming scarce and labour can be intensive i.e. 6+ hours to do valve cover gaskets. That all said, I love my 4 door 300zx
Great channel!
Oh wow. Mine just did not start up in a parking lot. It is acting like no spark...
1993 Infiniti J30 like you. 124k...
Great diag she finally took her car to the right shop.
like the video quick the the problem nice job
I have 95 Infiniti j30 and she still in great shape
Severe lack of service info about these cars on the internet. I have a 94 j30, definitely could use more info
Sometime I look up information for a Nissan maxima or even a pickup and find extra service information. Most engine information is the the same between them.
Hi, could you tell me what kind of shocks and struts can i use to replace the bad ones on my 1993 infiniti j30? Having a lot of trouble finding the parts.
I have a question, if you know.
When the ECU command the injector to spray the fuel, for example, 30% BTDC for 2,5 ms on idle , and then you press the accelerator pedal to 4000 rpm,and the command of the injector is now for 2,9 ms , the injector will start spraying the fuel 30% BTDC and for 2,9 ms ,or has some kind of advance (like the ignition),and start spraying the fuel a bit earlier and for 2,9ms?
And also, what about the variable valve timing engine?thanks.
Many engines will fire all the injectors at the same time while cranking and then switch to sequential injection. Once it switches to sequential injection the injector will fire with an advance. The advance probably doesn’t change much but the duration or pulse width will change. At higher rpm and high load the timing is irrelevant because the off time is shorter than the on time. On performance vehicles you have to install larger injectors if the on time is more 75-80% duty cycle.
I don’t know if the VVT angle affects the injector timing.
@@ThePracticalMechanic Thank you very much for the reply. I really appreciate the knowledge you are sharing with us. I have learned a lot. waiting for your next video....
I have the same exact car. 1993 Infiniti J30
Great diag .. I'm kinda confused though, was that a V8 or a V6? thank you
V6. 3.0 Nissan engine. Thanks for watching.
I have a 1995 Infiniti j30 and have a misfire on cylinder six new plug and coil pack was going to change the fuel Injector but don’t have a clue how to get it off.
There are two Phillips headed screws that are easy to round off holding the retainer in place on top of the injector. Once the retainer is removed I wiggle the injector until it begins to move side to side and the remove some pliers. Fuel from the fuel rail will drain into the cylinder so it is best to disable the fuel pump and run engine until it stalls to depressurize the rail.
I have a 1995 Infiniti J30 I want to change the suspension and shock absorbers It's hard to find parts for this car
i swapped my 1994 J30 to S14 240sx suspension & coilovers and i just helped a friend do the same. sway bars from the twin turbo 300zx also fit & reduce body roll
Ooo up my alley!! OLD. 😆
Awesome... great process. Code helped too, even if you didn't know nissan very well.
I ❤️ old cars too... They are honest vehicles with no BS 😁
Since these don't rust away in Colorado we still have tons of the old Nissan hard body trucks and Nissan cars. Luckily they almost always have the same failures.