misfire during acceleration

[Jay Zarcadius]

car starts hard and idles way high until it warms up. still has the surge if that makes a difference. car misses occasionally at idle, and stumbles pretty bad around the 1800-2300 RPM range. plugs are pretty new, and they look okay. IAT was out, thought that was the problem, got it replaced and it helped, but didn't cure it. has new ECU, new IAC motor, new TPS (just throwing everything out there) new fuel filter. no matter what it seems to run really rich, very strong smell. had CEL for IAT but has not come back since i replaced it. problem is not a boost leak, as my car is the NA 4g63 please help with other ideas.

 

[DevilsAWD]

car starts hard and idles way high until it warms up. still has the surge if that makes a difference. car misses occasionally at idle, and stumbles pretty bad around the 1800-2300 RPM range. plugs are pretty new, and they look okay. IAT was out, thought that was the problem, got it replaced and it helped, but didn't cure it. has new ECU, new IAC motor, new TPS (just throwing everything out there) new fuel filter. no matter what it seems to run really rich, very strong smell. had CEL for IAT but has not come back since i replaced it. problem is not a boost leak, as my car is the NA 4g63 please help with other ideas.

boost leak tester

just kidding.

I would check your coolent temp sensor. If its not reading it will make your car run rich. I know I'm experiancing the same thing on my turbo. basically it would start really hard. eventually it just wouldn't start and run. after disconnecting the sensor all together this is the condition I got.

my .02

Good luck

-Devs

 

[Jay Zarcadius]

thanks i'll check on that.

 

[Morphius]

After checking your coolant sensor, I'd look into your plug wires. They should be changed about every 40K. The seals in the plug holes for the valve cover will seap or leak over time. The boots on the plug wires will become saturated/micro cracked over time. The result is they will short across the boot to the motor and not to the plug resulting in a misfire.