I can crank the car up and head down the road and it will run fine for a minute or two then it will develop a misfire and sometimes it will backfire. I can stop somewhere and let it sit for 10 min or so and take off again and it will run fine and then start to misfire again. what could this be? crank or cam sensors? wiring or what? Thanks!
Need help misfires when hot?
- Thread starter FoxRod87
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trinity_gt
10 Year Member
Probably a coil pack or (hopefully not) a coil driver in the PCM.
Can you scan the PCM to find out which cylinder(s) are misfiring now, then swap the coils left to right and see if the problem follows the coil?
Can you scan the PCM to find out which cylinder(s) are misfiring now, then swap the coils left to right and see if the problem follows the coil?
trinity_gt
10 Year Member
More possibilities:
Have you scanned the codes? Is it one cylinder consistently or are you getting random misfires?
- crank position sensor
- PCM/coil driver
- PCM/injector driver
Have you scanned the codes? Is it one cylinder consistently or are you getting random misfires?
trombonedemon
Well-Known Member
Poor or unregulated engine timing is often a cause of intake backfires, but can also be responsible for exhaust backfires
Improper wiring in the ignition can also lead to timing issues and backfires
Low fuel pressure, clogged fuel filters, and weak fuel pumps could cause a severe lean air-to-fuel ratio during fuel injection
Missing or damaged catalytic converter can result in backfires out the tailpipe
These are some of the causes I've researched. I would check for intake leakes and maybe your cats have gone bad like the forementioned. Clean your MAF also. Might be some unmetered air.
Don't drive your car anymore until you figure this one out, b/c, early detonation will destroy pistons.
What octane of gas are you using?
Improper wiring in the ignition can also lead to timing issues and backfires
Low fuel pressure, clogged fuel filters, and weak fuel pumps could cause a severe lean air-to-fuel ratio during fuel injection
Missing or damaged catalytic converter can result in backfires out the tailpipe
These are some of the causes I've researched. I would check for intake leakes and maybe your cats have gone bad like the forementioned. Clean your MAF also. Might be some unmetered air.
Don't drive your car anymore until you figure this one out, b/c, early detonation will destroy pistons.
What octane of gas are you using?
wmburns
SN Certified Technician
40 PSI delta is perfect.
What is the condition of the spark plug wires? How old? What about routing? Try running the car in a totally dark location. Can you spot any spark leakage (blue)? Also do a visual inspection. Look for white spots esp where the wires touch anything.
Consider having your fuel injectors cleaned and flow tested. Try injectorrx.com. They have done well by me.
What is the condition of the spark plug wires? How old? What about routing? Try running the car in a totally dark location. Can you spot any spark leakage (blue)? Also do a visual inspection. Look for white spots esp where the wires touch anything.
Consider having your fuel injectors cleaned and flow tested. Try injectorrx.com. They have done well by me.
trombonedemon
Well-Known Member
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