help

[Brandon_l1000]

alright guys i know this isn't the right forum for this but you guys are the only ones i can ever get an answer from. so here goes my gf has a 99 honda passport. it started missing couple months ago. nothing bad but i put it on the scanner and told me a cylinder 4 misfire. i check the coil pack its good, then i changed the fuel injector nothing happened. so i tested the compression on that cylinder and it was good. well few weeks ago it got worse now when it idles it misses like crazy and tries to die. then it will rev itself to about 2000 rpm for a few sec then drop back down. also if you put it in gear and set with your foot on the brake, it will surge forward like you stomped the gas. this made me think maybe tps checked and its good. at this point i'm pullin my hair out you guys have any ideas at all?

 

[towman]

try switching the coil pack to another cylinder and see if the mis fire goes to that one

 

[foamypirate]

Sounds like you might have a vacuum leak at the intake manifold gasket.

 

[bucket]

Is it a coil pack, or coil-over-plug? If it's the later, are there any burned spots on the plug boot?

 

[HotRodPC]

Any engine codes at all??

 

[bucket]

Any engine codes at all??

He said it was put on a scanner and they found a cyl 4 misfire. I'll go out on a limb and say the only code was a P0304.

 

[HotRodPC]

I was more reffering to after he made the repairs and cleared it, but you'd assume NO, surely he rechecked for codes after the repairs of the items he tried.

 

[Brandon_l1000]

ok guys i thought of a vaccum leak somewhere but cant find one. i have changed the plenum gasket but no the lower ones. and i changed the coil packs and cleared the codes let it run for a while till check engine came back and still told me cylinder 4.

 

[Brandon_l1000]

Is it a coil pack, or coil-over-plug? If it's the later, are there any burned spots on the plug boot?

its the individual ones on each plug. and i havent noticed a burn but ill check

 

[HotRodPC]

As suggested. Move that #4 COP (coil over plug) to another cylinder. Swap it with say #2 or #1. Clear your codes. Then when the code comes back it's the # of the cylinder you moved the #4 COP to, then you have your problem found and replace that COP and all done.

 

[Brandon_l1000]

As suggested. Move that #4 COP (coil over plug) to another cylinder. Swap it with say #2 or #1. Clear your codes. Then when the code comes back it's the # of the cylinder you moved the #4 COP to, then you have your problem found and replace that COP and all done.

yeah that what i was saying i did that and it still gave me a cylinder 4.

 

[bucket]

Did you change the spark plug?

 

[Brandon_l1000]

Did you change the spark plug?

sure did lol im thinking about just taking it to a mechanic. i hate to but its at the point idk what else to check.

 

[HotRodPC]

Ahhh OK. Guess I skimmed. Proabably responded after just waking up from my nap. So #4 is misfiring with all new ignition components. Have you by chance done any checking on Honda forums for "KNOWN ISSUES" Every vehicle brand has its quirks. You might find it can be something like a bad crankshaft or camshaft sesor throwing the misfire #4 code, or causing the #4 to not fire. Does it run like it's actually missing? When a 4cyl is misfiring on 1 cylinder, that's 25% of its power lost, so it's quite noticeable unlike a V8 missing on 1 cylinder.

 

[Brandon_l1000]

Ahhh OK. Guess I skimmed. Proabably responded after just waking up from my nap. So #4 is misfiring with all new ignition components. Have you by chance done any checking on Honda forums for "KNOWN ISSUES" Every vehicle brand has its quirks. You might find it can be something like a bad crankshaft or camshaft sesor throwing the misfire #4 code, or causing the #4 to not fire. Does it run like it's actually missing? When a 4cyl is misfiring on 1 cylinder, that's 25% of its power lost, so it's quite noticeable unlike a V8 missing on 1 cylinder.

no but ill do that. and mans its running like a pig