gotswap

Turns out I have a bad ecu. I was sent the instructions to update it to MODS:C by desoldering a few items on the main board and now cyl 1 will not fire at all. Will be returning it for repair. Thanks for the help everyone.




4/11/08 Son of a hoar!!!

So I decided to do a bit more troubleshooting on my own before dropping $ on new injectors. I was able to recreate the issue; get the car warm shut it off for ~15 minutes and start it back up. Wala, misfire

I swapped the injectors 1 and 2 pulled the plug and it does not matter what injector is in cyl # 1. Pull the #1 coil while running and no spark pull the # 2 and has spark so swap them out let it get warm again and still get misfire. Pull out the #1 which was the #2 and put in a spare sitting in the garage. No misfire but I guarantee as soon as it gets hot it will start misfiring.

What is going on????? I am back to my original diagnosis is the heat screwing up the resistance on the coils so that they will not fire? What am I missing here?





UPDATE......4/5/08

I called my tuner and he made some adjustment to the temp map but it turned out that was not the issue at all.

Looks like I have a bum fuel injector that just randomly stops working after awhile, it seems that it is alway related to temp but not so much any more. GRRRR

Currently I have RC 750 saturated and I remember seeing it somewhere on the board that these injectors may have issues but can't find it anymore.

Is this true? I'm deciding on just getting a new one or ordering the peak and hold type but don't want to spend the extra cash if I don't have to. Please chime in if you are running saturated 750's or have advice.

Thanks!


So I need a bit of help here in diagnosing an issue.

Background

Custom turbo kit with AEM EMS tubular bottom mount log manifold

It seems that I am having a hard time keeping ignition coils in my car. After driving for a while and the underhood temps rise I develop a nasty misfire under load. It usually happens if I drive it, shut down for a bit to go shopping or whatnot and then drive off. I have been through 2 sets of coils in about 5000 miles so I am having a hard time believing this is the only issue.

I know for sure that it is heat related because it goes away if I let it cool 30-40 minutes or if I pop my hood to the safety latch while driving to get air under the hood.

HELP

Soul Coughing

what are you plugs gapped to? is it misfiring under load (WOT) or partial throttle around town stuff? usually decreasing the gap will cut down on misfires at WOT, or just changing your plugs.

gotswap

Brand new BKR7E .034 gap NGK coppers. The odd thing is it will idle fine but if I go full or partial throttle from idle at a stop or taking off it will miss fire.

I would think the gap is fine as it runs very good until the temps rise under the hood.

SilvCF2k

Hey mike. Hope you get this problem fixed.

Soul Coughing

try gapping them to .028, i had some misfiring on highboost and that stopped the problem.

Also, what is your A/F ratio when this happens?

gotswap

I'll try the gap

I knew I was going to get asked about the AFR, I'll have to recreate the issue and pay closer attention to my gauge. I'll check this before regapping.

gotswap

Thanks, it is always the little stuff that is the most annoying. I got tired of all the heat issues so I redid the whole hot side, that is fixed, but I am still chasing this issue.

gotswap

So do you think the heat is causing increased resistance and the coils are not able to fire over a .032 gap?

BTW I am only running 9.5 psi gauge but 6.5psi absolute due to the altitude here.

kutsujula

This happen to me on a different car I had, my old scion tc did this when it was boosted. Come to find out it was something to do with the amount of timing pulled. Not sure if this helps you what so ever but I thought I would throw this out there since I had a similar problem.

Soul Coughing

you could move up to a 8 in the heat range. That might help you as well. I am running the 8 range in the ngk iridiums. Try the gapping first.