So finally got the new longblock back in and fired it up last night. It ran about five seconds and died and never would restart. Sounded like it was loading up with fuel and then would try and spark. Pulled a plug and it was wet and smelled gassy. Checked one of the coils for spark and whoa major spark on that one but 7 more(running the ltcc). I guess im gunna check fuel pressure and test each coil with a plug with fuel supply shut off and probably use a noid light to see the relationship of plug firing to injector pulse. Am I looking at this in a good direction or should I try something else first? Im also a little concerned with my tune loading correct as I had trouble getting it through email and converted to were the jet would read it. My cam is similar to the cc503 just a little bigger. I guess im looking to be sure all 8 coils are working before I go much further and check that fuel pressure is good(as I did put racetronix pump with hotwire on it). If I dont have any luck with any of that I plan to put the coil and icm back on and stock wires and run opti as my ignition and try that. The ltcc is getting the optical sensor readings and is hooked up correct given they dont have the harness reversed and I doubt they do. So what is the relationship between injector pulse and spark. Also I didnt have the exhaust on and i had o2 sensors hooked up and did not have ram airbox or maf on. Did not think these would make enough difference as I just wanted to see if it was gunna run before I buttoned evrryhing else up. Appreciate any thoughts or advice including that im going the right direction or not.

 

Don't worry about the injector pulse vs spark timing. While the engine has sequential injection, which pulses the injector on the intake stroke of each individual cylinder (of course as duty cycle approaches 100% it can pulse on all 4 phases of the 4-stroke cycle), it would not cause the engine to run excessively rich.

Consider that the 93 batch fire system works well, and there is no relationship at all between the injector pulses and the spark. I've also run my sequential LT1 with the injectors 180-deg out of phase, and the differences are imperceptible once the engine warms up. When cold, the injector would be firing against a closed, cold valve, and you could lose some atomization. But again, it doesn't cause that big an issue. It showed up as a minor stumble until the valves started to warm up.

What are you using for a fuel pressure regulator? Check the pressure, and check the FPR vacuum compensation line for wet fuel. While the O2 sensors were hooked up, were they installed in the headers? And were the header collectors wide open, allowing a significant backwash of air with the low exhaust flow at idle? Id button up the exhaust if that was the case.

 

Yes in headers and they were open. Was gunna just button things up before I try to fire her again as I was concerned but didnt know if they would richen it up at startup. Thanks for the info. Its a stock fpr and almost pulled the vaccuum line last night but got sidetracked. I did depress the schrader valve and had fuel but didnt realy seem to be alot of pressure. I did check the fuel pressure before I took motor back out to seal the headstuds and was good then but was only checked with key on as didnt fire back then before decided to pull motor backout. Do you see any benefit of using the noid light as I check each coil? Also since ill have help to check coils is there any problems bleeding brakes without the assist of vaccuum and any tricks and since only the front was disconnected and do you need to start in rear passenger side and work closer or is the front seperated? I did see two bleed screws on the module they were disconnected from. I want to start there to get what I feel is the big air pocket out then move to the farthest point but havent searched out anything. Have. A great thanksgiving and thanks for giving advice.

 

When I was posting I was thinking it ran for 5 minutes before it stalled, not 5 seconds. The open O2 sensors wouldn't be a factor until it went into closed loop. Forget what I posted with regard to the O2 sensors.