Near as I can tell, in a fuel system, a pressure leak is a fuel leak? The only place it should leak is between the injector and the rail or the injector and the manifold?

 

well, injectors and new boshe copper plugs are in and running. . . when cold ( first ten minutes of driving ) i still cannot go above 1.0bar without hearing popcorn sounding detonations. After its really warmed up i can bring it up to 1.2 no issues. Whats left ? coil packs ? head gasket leak ?

 

did u put a durametric on it and test for misfire? is it iso to one cyl? mine was doing the same thing and it was a bad coil pack on cly 3

tim

 

Well, i ran the durametrics a few times, i cannot get it to record a misfire ! and thats sooo odd because you would think detonation noises would register misfires. . . . No misfire codes either. Code free. ARRRGGGG. I could just try a set of coilpacks, any chance it can be a headgasket ? When the engine is HOT its fine ( from what i can tell, 1.2 bar no problem )

 

Poor running when cold and then running fine when warm is classic cracked coil symptoms...I would replace them. I had this a few years ago with no codes and the dealer knew it was a coil immediately from the cold/hot running change.

 

Gotcha, i think its worth a try, do you have any discounts on them ?

 

Dumb question, but the ecu tune was upgraded along with the injector change, right?

Also, what was the solution to your injector installation issue?

 

injector install was only to increase the margin of safety, the issue was there far before injectors were even thought of. Todd said to just run the tune for now, the ecu has adapted fine, being that i went down to a 3.8 fpr it kinda balances out.

 

Dean, are the injectors working ok with appropriate duty cycles? Any tips for future installers?

 

sorry john but im going to have to disagree... a coil will misfire regardless of temp.. however if it does clear up once you made a couple of pulls im thinking the flame may be getting snuffed out in the cyl.. what is the ambient air temp when its doing it?? does it do it in the summer?? what gas are you running?? how old is the gas?? what is the temp/type of plugs are you running??

tim

 

excellent questions, and it IS effected by colder air, i will say below 45 degrees. Pump gas. I will now pour in 100 octane. Todd said if it doesnt occur at 100oct then its not coils. Instead its more of nature of the engine. So i may try a set of coils anyways. Wouldnt be a bad idea at 20k hard miles. In end it may really be nature of the engine, when in stock form i think i recall the engine behaves different until hot. But now with all this power and boost, it will exagerate any traits i suppose.

 

Tim,

All I have to go on is that my car would sputter at start-up until warm, then run fine. It was a single bad coil. I know someone else that had the same problem, so this is one possible way they can behave when they are defective. I am sure there are others ways they can behave when broken, depending on how they fail.

 

If I remember I had four bad coils. They all had cracks. At the time, my car only had 13K miles. I never heard a popcorn sound rather my car would hiccup or stutter just for a moment when I got into it. Once the coils were replaced (I replaced all of them) the problem was solved.

 

I'm betting that's my problem too. We logged a misfire on Cyl 2 consistantly around 2500 or so and it has a slight stumble on accel after a steady throttle regardless of rpm.

 

change coils every 2nd time you change plugs... period.. or once a year.... especially if ur boosting.... inspect them as well....