This fella's brilliant. Anyone doing this conversion should watch the whole series. If you buy an AC Delco kit that has all the harnesses, there's more information than you need, but watch them all - you'll learn a lot. I'm in the process of doing the same conversion and wish I'd found this series sooner!
I’ve recently found an alternative source for the over temperature alarm switch. I updated the description in Part 4b with a link to the parts kit. If anyone try’s it out post back here how it worked out.
I've been struggling with getting my 1998 mercruiser 305 5.0L carb to start. Pretty much the only thing I haven't touched yet is the ICM. Is there a test I can do to see if it's toast? There has been so many things wrong with this motor as I inherited it from an auction. But, when I finally got it to turn over and idle. It would eventually have a backfire through the carb, and stop. Then, as I started it again, the length of time it idled grew less and less. It was not able to increase in rpm and Rev higher, but that was due to a plugged venturi. I drained the fuel tank of bad fuel. But still that yellow varnish left behind. Psi of fuel pump is at 7 psi. Within range of 3-7 per the manual. I've rebuilt the carb 2x. I've ensured the float is at proper mm distances. I have the idle screw at 1.5 at the moment, though oddly the Manual has 1.25 in another location. I've replaced the ignition coil. Re-lapped the valves, good cylinder psi. I'm feeling utterly defeated here. Not sure where to turn or what to do. Been working on this over a month now. Please help? Edit: I forgot to mention that all it does now, is with starter fluid or not, either way, it's only within the first 3 or 4 first piston ignitions that ignition seems to happen. Then after that, it just turns and turns with nothing happening. I will turn the key off. Wait a second. Then start it again and again, first few pistons fire off - them there is nothing. I don't know what to do. I'm out of my league here. Super frustrated.
Welcome to Thunderbolt Ignition Wonderland. The solution is right in front of you. Do you really think I’d go to all the trouble to create all these videos about replacing the Thunderbolt Ignition for no reason? There is no test, there is no logic you can apply, there is only one solution you can do and that’s replace the Thunderbolt ignition system with a Delco EST ignition. You could try replacing the optical pickup in the distributor since you’ve already replaced the coil. But there is no test for the module. It’s a mysterious beast that will tempt you for weeks by half working and then not working. The link you posted on says it’s obsolete. Follow the link in the description to the more recent Sparkie the Eel playlist to find your way out of Thunderbolt Wonderland.
I have a 4.3L/V6 Mercruiser with a Thunderbolt IV that do not start. Is mounted in a Rinker 181 from 1992. The ignition coil is OK. The thunderbolt IV work but still no spark. The distributor # is 90577. I think the internal sensor in the Distributor does not work. My question is: can I replace the whole system with SKU 480140 ( 4.3L/262ci GM Delco EST 1103993 Marine Electronic Distributor) from Marine Engine Depot. (They say this replaces 807964A1). Any suggestions. Thank You.
You need a kit. Part 480140 is just the distributor but you need a whole kit. Get this kit fast because they sell out quick. marinepartssource.com/delco-est-4-3l-v6-ignition-conversion-kit-4-3l-v6-sierra-18-5513?gclid=Cj0KCQjwgYSTBhDKARIsAB8KuktiARTybl_ejOigWQhgmhd3YuHkz6Z4bhPZS4JxJHPh7crCgtNsUJMaAkt-EALw_wcB There is a problem with this kit. The ignition coil has a bracket designed to fit the 3.0 Mercruiser engine. If you mount it to the back of a V6 or V8 cylinder head you can only use one of the bolt holes which isn’t as solid. Vibrations might eventually damage the coil. I sell a coil and bracket that will use two bolt holes and turn the ignition coil such the spark wire tower points up instead of back. It’s a better more robust coil solution and includes a genuine GM coil. Here is a link to my video about my coil bracket product. ua-cam.com/video/PkusGQYEvUE/v-deo.html
Great video just seeing how much effort you put in it. But have a 1991 5.0 LX with a thunderbolt 4 and I’m having the same problem is and I would like to do that conversion to the Delco est if you can please help me find out what part number or we’re to get it I have called several locations and they don’t carry it at all
Contact “Marine Engine Depot” at this link; marineenginedepot.com/distributor-kit-57l350ci-74l454ci-gm-delco-voyager-est They seem to have the V8 kit in stock. It’s part number 481111. It doesn’t say it works with a 305 but it will work if you set the base timing to 10 degrees BTDC.
Off topic question maybe you could help me with. I cannot get into base timing mode with my 96 4.3LX Mercruiser with the thunderbolt ignition. I ground the purple/white wire directly to the battery *before* I start the engine but it makes no difference in timing with or without. Also it still advances when I rev the engine. Boat is new to me and engine is new, previous owner froze it. I have this one running pretty good by ear and am ready to do the final adjustments. I also notice my tach doesn't work.(bad module maybe?) Replacing parts can get expensive and you seem to be one of the most knowledgeable youtubers on the subject. Any suggestions?
Did you solve this? I have a thunderbolt v system 5.0 v8 mercruiser too and it won't go into timing mode. Timing will still move when I rev it whilst purple and white wire is grounded.
I will give you some advice. Just find an ac delco 4.3 distributor shaft. It comes with the ignition module inside. Than find the coil. Real simple to install and wire up. Just need your power wire and a ground. No need to pay high prices from a marina as they are the exact same parts but cheaper
Negative ghost rider. Truck and car modules are not the same ignition module. You MUST use a marine ignition module to get the proper timing curve for a 4 cylinder, 6 cylinder, or 8 cylinder. Watch the whole series on the Thunderbolt replacement system. Car and truck module timing curves are not designed to run during normal operation. They were only used during limp home mode and had very weak timing curves to protect the engine. Your boat won’t have design power when you set the timing per factory procedure.
Car and truck modules don’t even kick in until about 1500 RPM. Then it’s a fixed advance of about 13 degrees regardless of increasing RPM. That’s only during limp home mode when the ECM is not controlling the timing. The ECM had complete control of the timing under normal operation. Boat ignition modules are under control of timing at all times so they have a more precise curve for the engine starting at 600 RPM. Watch the whole series to see the timing curves.
@@moccasinmarine I don't know where you are getting your information from. But you have no clue on what you are talking about. First off, ignition module is just an on off switch. Man the stupid people who fix boats. I think you need to go back to school and learn something. Also stop believing the BS some wannabe mechanic at Mercruiser tells you. There is no ecm on your engine. It is a basic 1990 chevy 4.3l with a carb on it. Some door knob at mercruiser thought it would be a great idea to install a cheap $39 computer control to the side of a distributor without knowing what it actually does. Every non computer 4.3l distributor has the same thing you just mention. I have been doing this for over 25 years. So please don't try to make yourself sound smart. I guess you know nothing about mechanical or vacuum advances that comes in some distributors.
I’m a fuel injection expert. I sold GM fuel injection systems for 10 years for cars and trucks and I have timed car and truck modules and they are not the same as the marine ignition modules. If I have to post a video to prove what I’m saying I will but I’d rather just delete your comment as it’s full of insults. Since you are doubting me you go do the work to prove me wrong with hard data and not your opinion. You make a lot of assumptions that are wrong. If you think an ignition module is just a switch there is nothing more I can say to you. And if you make any more insults I’ll delete your comment but I’d like viewers to see bad information and steer away from it. EDIT: I’ve read your comment again and think I’ve figured this out. You are confusing 1970s ignition modules with 1990s modules. 1970’s modules were just electronic switches with mechanical advance and vacuum advance devices. This video is about Delco EST ignition systems so in that context I’m talking about 1990s era modules. These modules are both computer controlled and stand alone. In cars and trucks they are stand alone only when the computer is not digitally controlling the engine. This is called limp home mode is only used during rare abnormal situations when the ECM is not running in digital mode. In boats a similar, but not the same, module runs in stand alone mode all the time when paired with a carburetor. In both type modules there is an electronically generated timing curve. In cars and trucks it’s a basic 13 degree advance that begins at 1500 RPM and does not advance past that amount with more RPM. In boats there are three different curves from 600 RPM and smoothly up and the curves are automatically selected by the module depending on what size engine it’s installed on. The proof of this is in this video series. So in a sense we’re both right just talking about different technology in different years. But going forward leave off the insults. This is my channel and I have the right to remove comments that do not advance learning without insults. I ask that viewers that want to challenge what I publish put forth facts and data to back up their counter claims. I’m open to correction at any time but I’ll have to see data that contradicts my claims.
@@moccasinmarine It is obvious you weren't any good at your job. How about I have been doing it for 30 years.Worked for GM and was a grand master. They are 1000% the same. Your comments prove you know nothing at all about an ignition module. It is just an on off switch. Nothing more. A simple internet search will prove you wrong. What you are removing off the motor in your video is an aftermarket electronic ignition system that Mercruiser either designed or bought from some other company and put their name on it. Just like many other companies that sell a conversation kit. Go a head and delete the comments, it will prove you know nothing
Yes text your full name, shipping address, email, and your engine serial number and I’ll send you a quote/invoice for the kit you need. Text me at +17063583175.
Obviously a man that knows his job. Great video, well explained, short and to the point and no B.S.
Thanks but I’m about to do a complete new series on installing my own kits I’m selling now. Stay tuned.
As I've mentioned in other videos of yours, these videos are invaluable. Thank you for sharing your knowledge and experience with all of us.
This fella's brilliant. Anyone doing this conversion should watch the whole series. If you buy an AC Delco kit that has all the harnesses, there's more information than you need, but watch them all - you'll learn a lot. I'm in the process of doing the same conversion and wish I'd found this series sooner!
I’ve recently found an alternative source for the over temperature alarm switch. I updated the description in Part 4b with a link to the parts kit. If anyone try’s it out post back here how it worked out.
Saved my day, I’ve spent a day trying to figure all this out. Thank you!
Glad it helped.
I've been struggling with getting my 1998 mercruiser 305 5.0L carb to start. Pretty much the only thing I haven't touched yet is the ICM. Is there a test I can do to see if it's toast?
There has been so many things wrong with this motor as I inherited it from an auction. But, when I finally got it to turn over and idle. It would eventually have a backfire through the carb, and stop. Then, as I started it again, the length of time it idled grew less and less. It was not able to increase in rpm and Rev higher, but that was due to a plugged venturi. I drained the fuel tank of bad fuel. But still that yellow varnish left behind. Psi of fuel pump is at 7 psi. Within range of 3-7 per the manual. I've rebuilt the carb 2x. I've ensured the float is at proper mm distances. I have the idle screw at 1.5 at the moment, though oddly the Manual has 1.25 in another location. I've replaced the ignition coil.
Re-lapped the valves, good cylinder psi.
I'm feeling utterly defeated here. Not sure where to turn or what to do. Been working on this over a month now. Please help?
Edit: I forgot to mention that all it does now, is with starter fluid or not, either way, it's only within the first 3 or 4 first piston ignitions that ignition seems to happen. Then after that, it just turns and turns with nothing happening. I will turn the key off. Wait a second. Then start it again and again, first few pistons fire off - them there is nothing.
I don't know what to do. I'm out of my league here. Super frustrated.
Welcome to Thunderbolt Ignition Wonderland. The solution is right in front of you. Do you really think I’d go to all the trouble to create all these videos about replacing the Thunderbolt Ignition for no reason? There is no test, there is no logic you can apply, there is only one solution you can do and that’s replace the Thunderbolt ignition system with a Delco EST ignition. You could try replacing the optical pickup in the distributor since you’ve already replaced the coil. But there is no test for the module. It’s a mysterious beast that will tempt you for weeks by half working and then not working. The link you posted on says it’s obsolete. Follow the link in the description to the more recent Sparkie the Eel playlist to find your way out of Thunderbolt Wonderland.
love your mercruiser videos, thanks
Appreciate the compliment.
I have a 4.3L/V6 Mercruiser with a Thunderbolt IV that do not start. Is mounted in a Rinker 181 from 1992. The ignition coil is OK. The thunderbolt IV work but still no spark. The distributor # is 90577. I think the internal sensor in the Distributor does not work. My question is: can I replace the whole system with SKU 480140 ( 4.3L/262ci GM Delco EST 1103993 Marine Electronic Distributor) from Marine Engine Depot. (They say this replaces 807964A1). Any suggestions. Thank You.
You need a kit. Part 480140 is just the distributor but you need a whole kit. Get this kit fast because they sell out quick.
marinepartssource.com/delco-est-4-3l-v6-ignition-conversion-kit-4-3l-v6-sierra-18-5513?gclid=Cj0KCQjwgYSTBhDKARIsAB8KuktiARTybl_ejOigWQhgmhd3YuHkz6Z4bhPZS4JxJHPh7crCgtNsUJMaAkt-EALw_wcB
There is a problem with this kit. The ignition coil has a bracket designed to fit the 3.0 Mercruiser engine. If you mount it to the back of a V6 or V8 cylinder head you can only use one of the bolt holes which isn’t as solid. Vibrations might eventually damage the coil. I sell a coil and bracket that will use two bolt holes and turn the ignition coil such the spark wire tower points up instead of back. It’s a better more robust coil solution and includes a genuine GM coil.
Here is a link to my video about my coil bracket product.
ua-cam.com/video/PkusGQYEvUE/v-deo.html
Merci beaucoup ❤❤❤❤❤❤
Great video just seeing how much effort you put in it. But have a 1991 5.0 LX with a thunderbolt 4 and I’m having the same problem is and I would like to do that conversion to the Delco est if you can please help me find out what part number or we’re to get it I have called several locations and they don’t carry it at all
Contact “Marine Engine Depot” at this link;
marineenginedepot.com/distributor-kit-57l350ci-74l454ci-gm-delco-voyager-est
They seem to have the V8 kit in stock. It’s part number 481111. It doesn’t say it works with a 305 but it will work if you set the base timing to 10 degrees BTDC.
Off topic question maybe you could help me with. I cannot get into base timing mode with my 96 4.3LX Mercruiser with the thunderbolt ignition. I ground the purple/white wire directly to the battery *before* I start the engine but it makes no difference in timing with or without. Also it still advances when I rev the engine. Boat is new to me and engine is new, previous owner froze it. I have this one running pretty good by ear and am ready to do the final adjustments. I also notice my tach doesn't work.(bad module maybe?) Replacing parts can get expensive and you seem to be one of the most knowledgeable youtubers on the subject. Any suggestions?
I’m working on a Thunderbolt V system now. I’ll have a full answer tomorrow.
@@moccasinmarine Thank you
Did you solve this? I have a thunderbolt v system 5.0 v8 mercruiser too and it won't go into timing mode. Timing will still move when I rev it whilst purple and white wire is grounded.
@@tomunger2343 I didn't solve it, I believe the module was faulty . I upgraded to a newer ignition system.
Fun fact, you also cant find the 4 barrel carb if you are unlucky enough to have that on your mercruiser motor...
This particular carburetor is a Carter AFB or Edelbrock 1406. They are all over the place. Don’t get Mercruisered.
Hey man, have you done a video like this about the second version of this module?
Check this out:
ua-cam.com/video/bOVPZf8Q6kk/v-deo.html
I will give you some advice. Just find an ac delco 4.3 distributor shaft. It comes with the ignition module inside. Than find the coil. Real simple to install and wire up. Just need your power wire and a ground. No need to pay high prices from a marina as they are the exact same parts but cheaper
Negative ghost rider. Truck and car modules are not the same ignition module. You MUST use a marine ignition module to get the proper timing curve for a 4 cylinder, 6 cylinder, or 8 cylinder. Watch the whole series on the Thunderbolt replacement system. Car and truck module timing curves are not designed to run during normal operation. They were only used during limp home mode and had very weak timing curves to protect the engine. Your boat won’t have design power when you set the timing per factory procedure.
Car and truck modules don’t even kick in until about 1500 RPM. Then it’s a fixed advance of about 13 degrees regardless of increasing RPM. That’s only during limp home mode when the ECM is not controlling the timing. The ECM had complete control of the timing under normal operation. Boat ignition modules are under control of timing at all times so they have a more precise curve for the engine starting at 600 RPM. Watch the whole series to see the timing curves.
@@moccasinmarine I don't know where you are getting your information from. But you have no clue on what you are talking about. First off, ignition module is just an on off switch. Man the stupid people who fix boats. I think you need to go back to school and learn something. Also stop believing the BS some wannabe mechanic at Mercruiser tells you. There is no ecm on your engine. It is a basic 1990 chevy 4.3l with a carb on it. Some door knob at mercruiser thought it would be a great idea to install a cheap $39 computer control to the side of a distributor without knowing what it actually does. Every non computer 4.3l distributor has the same thing you just mention. I have been doing this for over 25 years. So please don't try to make yourself sound smart. I guess you know nothing about mechanical or vacuum advances that comes in some distributors.
I’m a fuel injection expert. I sold GM fuel injection systems for 10 years for cars and trucks and I have timed car and truck modules and they are not the same as the marine ignition modules. If I have to post a video to prove what I’m saying I will but I’d rather just delete your comment as it’s full of insults. Since you are doubting me you go do the work to prove me wrong with hard data and not your opinion. You make a lot of assumptions that are wrong.
If you think an ignition module is just a switch there is nothing more I can say to you. And if you make any more insults I’ll delete your comment but I’d like viewers to see bad information and steer away from it.
EDIT: I’ve read your comment again and think I’ve figured this out. You are confusing 1970s ignition modules with 1990s modules. 1970’s modules were just electronic switches with mechanical advance and vacuum advance devices. This video is about Delco EST ignition systems so in that context I’m talking about 1990s era modules. These modules are both computer controlled and stand alone. In cars and trucks they are stand alone only when the computer is not digitally controlling the engine. This is called limp home mode is only used during rare abnormal situations when the ECM is not running in digital mode. In boats a similar, but not the same, module runs in stand alone mode all the time when paired with a carburetor. In both type modules there is an electronically generated timing curve. In cars and trucks it’s a basic 13 degree advance that begins at 1500 RPM and does not advance past that amount with more RPM. In boats there are three different curves from 600 RPM and smoothly up and the curves are automatically selected by the module depending on what size engine it’s installed on. The proof of this is in this video series.
So in a sense we’re both right just talking about different technology in different years. But going forward leave off the insults. This is my channel and I have the right to remove comments that do not advance learning without insults. I ask that viewers that want to challenge what I publish put forth facts and data to back up their counter claims. I’m open to correction at any time but I’ll have to see data that contradicts my claims.
@@moccasinmarine It is obvious you weren't any good at your job. How about I have been doing it for 30 years.Worked for GM and was a grand master. They are 1000% the same. Your comments prove you know nothing at all about an ignition module. It is just an on off switch. Nothing more. A simple internet search will prove you wrong. What you are removing off the motor in your video is an aftermarket electronic ignition system that Mercruiser either designed or bought from some other company and put their name on it. Just like many other companies that sell a conversation kit. Go a head and delete the comments, it will prove you know nothing
Why would mercruiser mount an ignition module to a hot manifold riser?
There is a plate with an air gap so the module doesnt rest directly on the exhaust plus the exhaust is water cooled so it doesn’t get that hot.
I’ve edited the description to describe an error in this video.
Hy! Are you still selling these kits? I need one while it`s still summer :)
Yes text your full name, shipping address, email, and your engine serial number and I’ll send you a quote/invoice for the kit you need. Text me at +17063583175.
nice
Where Is your shop location?
Email GMefiguy@gmail.com for answer
useful video but repeat yourself too much and it's hard to pay attention
Ok sorry