Multiple Misfires
 

MY04

I have all 4 cylinders having random misfires at idle only, car never dies. any ideas??

Background:

I have a brand new cylinder head, timing chain and TCT, compression is good, plugs are new, leakdown test passed..

Suggestions are welcome..

wow, still misfire after all that? that work SHOULD basically cover the whole misfiring issue. aside from the work you did, all I can suggest would be changing the ignition coil packs (unless that's what TCT means??).

did you break in the new head for at least 500 miles or so, then do an oil change??

also, bad gas could be the culprit...try running to super empty on the tank you're on now, fill the tank with good 91+ octane gas (in Canada, Shell is our best, Sunoco is good too), then clear the codes and drive the car thru at least half that tank and see if the codes come back.

I have done proper break in.. Gas is out of the question.. I only run Shell 93 and problem has been going for at least 12k.. I only noticed it when I put the invidia exhasut on bc the missing is loud.. has only thrown a set of codes 3-4 times in 12k.. Only when she sits and idle for long periods will it throw codes.. You can always hear the car misfiring no matter how long it has run though...grrrrrrpopgrrrpop pop grrrrrrrrrr


Coil packs?? All 4 could be magically bad and wouldnt cause misfires at anything but idle??

TCT- Timing Chain Tensioner

Injectors.

And make sure your plugs are gapped.

Why is this post here instead of UTH?

You'll get more help there.

I just flow tested the injectors and they are ok.. I ran Inject-R Clean throught them while I had them off just to be safe..

I Swapped coil packs with a freind yesterday and no change.. What else is left???? :confused:

Sorry about mispacment I wasnt sure what would be best..

There are tons of threads on this in Under the Hood.

I would also check your MAP and TPS sensors, if that doesn't work just have a dealership run a diog.

Right on! Thanks for the help.. It is still under warranty so I may just take her in.. I just hate the fact that im going to have to reinstall the stock exhaust or they will likely void my warranty..