So I have a strange problem. I have the greddy kit with a map and ignition harness and a great tune. But the strangest thing keeps happening the 1st startup of the day for the 1st 10 to 15 minutes the car missfires like crazy but only in cylinder 4. Then after the warm up the car runs great and perfect. So I'm thinking its a plug, coil, injector. Or wire. Any ideas or suggestions. What would do that or what to check? Thanks in advance. James

 

next time your down, we can try and swap out things specific to that cylinder.

 

Well I'm gonna try 2 get down there tomorrow but was avoiding wasting ur time if anyone had a solution

 

I would hesitate to say its coil or it would happen all the time. A plug is my thought but I could be wrong.

 

I remember during my TT install, we kept getting a ton of misfire . . . turns out to be a bad RPM adapter. Who knew !

G

 

if you figure it out, please let me know I am sort of in the same boat.

 

350g were u seeing the missfire in all cylinders or was it isolated to only 1 like mine is. I haven't had a chance 2 check into further yet but will keep u updated 1 2 nv. Thanks for the replies

 

It was actually in 2 cylinders. We initially thought it was #4, but it turned out to be #3 & #4. What's weird is that even with 2 cylinders down, it didn't seem to be missing "that bad."

 

I'd check the plugs. If they are fouled, or otherwise damaged, they might misfire when cold.

That's about all I can say. If you have a good tune, my first suspect would be plugs...then work through the other options from there.

 

I had the same problem. I had my mechanic checked all the coil, spark, and injector. They are all fine. No clue how it happened.

 

Devil do u still have the problem? If not what did u do?

 

I had TS reflash my ECU. Now the SES light go off, but the missfire problem still there. Sharif @ suggest me to gap the spark plugs to factory gap. I will try that tomorrow morning to see what happen.

 

Ive been thinking on trying the stock gap for my plugs . I get a multipal miss fire at start up . I changed out the plugs and its still getting the code when it doesnt want to start up very good . Most the time it fires right up...no problem...but some times it kinda chugs for a few seconds . [built motor , cams , bigger injector , return fuel . iridium plugs..gap not changed ] .

 

Update. I swapped the plug and coil from cylinder 4 into another cylinder and still get a code and random missfire in cylinder 4. Here's a small theory of mine perhaps the ecu resets some things when it sits so long and that's why its only after a long sit but why only cylinder 4? Could a damaged ecu do that? Sorry if its stupid.

 

After I re-gap the spark plugs. It doesn't really help. It still misfire sometimes, and SES light come on. I just reset the ECU if the light is on. Getting tired on this thing.

 

Fellas, I would take a serious look at your RPM adapter. A wire could be loose or the adapter simply bad (this happened to me) . . . have your tech inspect it. What's the worse that could happen? Just verify that you have output on #4. I thought I only had one cylinder out and it turned out to be two . . . bad outputs on the RPM adapter. Kenji @ Greddy overnighted them to me.

G

G

 

Right now I don't have my Emanage installed. The TS guy took it off from my car when he do the reflash. He just leave the RPM adaptor installed for the RPM signal for HKS turbo timer only. I will try to take out the adaptor tonight to see if it is better. Thanks

 

Hmm . . . that sucks. I suppose it couldn't hurt to check the wires since we know the emanage was hooked up at some point and your plugs / coils appear to be gapped or working properly. Although its a long shot, have you tried swapping plugs on #4?

G

 

I have a theory! If you have the fuel system it sounds like the lower intake manifold is touching the fuel rails and causing a vacuum leak. The drivers side is more problematic as far as the fuel rails touching and causing leaks and this would cause the misfire code. Use the method I used to see where it was touching. Put white-out on the lower plenum and tighten it down all the way and look for the white-out marks. That's where the lower plenum needs to be trimmed. This happened on my #6 cylinder.
Alan

 

I was having the same problem with my car with the multiple misfire and #4 cylinder misfire. I burned out 3 coils in 2 weeks after having the TT stup for over a year. I took out the wiring herness and there was only 1 wire that the wrap pulled back a little and the wire was exposed. It was still in the bundle of all the other wires but still exposed. It was the Grey wire where the rpm adapter was soldered on. I have rewraped the wires and reinstalled the wiring harness and have gotten on it a little with no problem yet. (YET) I am waiting for the next hot day out to see if it happens again. I will post results.