StayTunedRacing Posted October 2, 2020 Share Posted October 2, 2020 My question is would a misfiring engine sputtering when cold be cause by a ICM. I’ve refreshed the carb w a kit from auto zone, new platinum plugs, cleaned the wiring and after the carb rebuild it was turn key, but after a while the plugs fouled out and everything went downhill. Please anything would help, TIA. Link to comment Share on other sites More sharing options...
Gary Lewis Posted October 2, 2020 Share Posted October 2, 2020 Kevin - Just sent you an email. But yes, the ignition module can cause poor running. When I fired up Big Blue's new engine for the first time about a month ago it ran horribly. But I needed to keep it running for at least 20 minutes to break in the cam. Meanwhile I noticed that it backfired a bunch and wouldn't run hardly at all above 2000 RPM. And, the tach did weird things. After the break-in I swapped ignition modules and it ran dramatically better. Totally different. But you haven't told us what carb you have. And some carbs can have failures that cause the air/fuel ratio to be so rich that the plugs load up. So tell us more about what you have? And maybe put some of that in your signature? It'll help us help you w/o having to ask a lot of questions. Link to comment Share on other sites More sharing options...
old55pete Posted October 3, 2020 Share Posted October 3, 2020 The other thing you could tell us is what the exhaust smells like, ie, raw gas, oil? Those two tidbits will also give us a clue also. Link to comment Share on other sites More sharing options...
FuzzFace2 Posted October 4, 2020 Share Posted October 4, 2020 The other thing you could tell us is what the exhaust smells like, ie, raw gas, oil? Those two tidbits will also give us a clue also. Even better what we are working on Is this the 250? Before I would change out the ICM I would install the plugs the truck was made to run on and not them big $$ plugs as they have been known to cause issues. Go with a good old copper plug and see what happens first. Dave ---- Link to comment Share on other sites More sharing options...
StayTunedRacing Posted October 4, 2020 Author Share Posted October 4, 2020 The other thing you could tell us is what the exhaust smells like, ie, raw gas, oil? Those two tidbits will also give us a clue also. Even better what we are working on Is this the 250? Before I would change out the ICM I would install the plugs the truck was made to run on and not them big $$ plugs as they have been known to cause issues. Go with a good old copper plug and see what happens first. Dave ---- not really much smell from the exhaust, maybe more gas than it should? After I rebuilt the carb i had the copper plugs and those fouled out so i was wondering if it needed to be hotter and put the platinum and it ran a bit better but this pic is the first set of plugs, tried a compression test to see if thats why i felt a misfire and cyl 5/6 weren't working with the hose for the tool. After i rebuilt the carb and put the copper plugs it fouled them out here the plugs go left to right 1-6 there was lots of rust in the tank too but everything was cleaned out and i have a clear filter on the line before the carb so everything is clear, its cheap to replace the ICM so ill do that today and let you guys know but i honestly dont see why a computer would cause a misfire, i ran through the cables and tested and cleaned everything no clue how to rotate these images Link to comment Share on other sites More sharing options...
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