Help!! Misfire

[Ghost1984]

Alright guys for the last few weeks my car has been misfiring bad, so i put new plugs in, i tried the ngk bp6res plugs(i have a 1st gen 2.0, mild modifications, intake, header etc....)and i also put on some wires that i got cheap at pep boys(yea i know) just incase it might be the wires, i put them all on, gapped the plugs at 0.40 and it still misfires when idling and when im driving partial throttle, doesnt seem to do it under wot, or unless its not as noticeable, it couldnt be the coil because that either works, or it doesnt work. i have no ideas on what it could be, anyone with some suggestions. Thanks.

 

[GSGoinFast]

When mine did the same thing it was a bad wire. but since you already replaced them, my guess would be maybe your timing belt slipped a little bit. just a guess tho

 

[Ghost1984]

me and pogitsi checked the timing and it was fine, so i dont think its that, i thought it was the wires to thats why i went ahead and changed them....but its not, im not sure what else could cause this....im so stumpt right now

 

[VooDooLASER77]

Make sure the wires are on right, tight and the spark plugs are good. You may also have a mild vaccum leak...Do you hear any hissing? Did you look at your coil pack and ECU?

 

[Ghost1984]

i was told it couldnt be the coil pack because it doesnt just barely work, it eithe works or it doesnt, i checked the ecu, it didnt have any burn marks or the caps dont seem to be leaking, the wires are on tight and the plugs are brand new ngk's and gapped correctly, as far as the vacuum leak im not sure about that and where to check. anyone?

 

[VooDooLASER77]

i was told it couldnt be the coil pack because it doesnt just barely work, it eithe works or it doesnt, i checked the ecu, it didnt have any burn marks or the caps dont seem to be leaking, the wires are on tight and the plugs are brand new ngk's and gapped correctly, as far as the vacuum leak im not sure about that and where to check. anyone?

You want to check all over the engine. Put your ear close to the engine and listen for a hissing noise. A good method I have used for many years is to get a propain torch and open the gas valve (DONT LIGHT!) just let the gas run. If there is a good size vaccum leak, the car will die (by sucking in propain).

If the coail pack has a small crack and mositure is getting in..It can still work!

Also, check the resistance on your fuel injectors. You might have a faulty one..

 

[Ghost1984]

well i know its not the plugs, or wires, could be the coil, but i my idle is funny too i had it put at 750rpm, and when i started driving around for about 20-25 minutes it was misfiring again and when i had to stop the idle would be up at like 900rpm even when i had adjusted it, and when the cooling fans kicked on the idle got real rough. what else could cause a misfire and a rough idle?

 

[VooDooLASER77]

well i know its not the plugs, or wires, could be the coil, but i my idle is funny too i had it put at 750rpm, and when i started driving around for about 20-25 minutes it was misfiring again and when i had to stop the idle would be up at like 900rpm even when i had adjusted it, and when the cooling fans kicked on the idle got real rough. what else could cause a misfire and a rough idle?

Did you check the vaccum lines? Hear anything? Is your check engine light on? I sounds to me as if your IAC could be bad..Check the sensors around the throttle body. You have to start with Air, fuel and spark and work your way forward. Investing in a good volt meter and a chiltons manual might do you good!

Good Luck