lt1 383 wont start need help!!
lt1 383 wont start need help!! well ive had a problem with my car running real rich and found some problems such as the car having the wrong size injectors programmed in and a bad o2 sensor... but pcmforless reburned my chip and the car fired up and ran a little rich but ran the best it has with the new motor. i have datamaster and was going to datalog the car but went out the next day and it wont run at all and has no communication with the computer with neither my laptop and datamaster or with my snap-on scanner. this is a new computer and chip and went from running to busted in a day? so i need some help b4 i throw a carb on it and give up on the efi! ... i sure hope its not the computer again 93's are hard to find lol
specs are
93 z28
6spd
383
gm 847
ported heads
pcmforless tune
new comp (old one got water in it but new one is all watertight )
42lb injectors
specs are
93 z28
6spd
383
gm 847
ported heads
pcmforless tune
new comp (old one got water in it but new one is all watertight )
42lb injectors
Launching!
Joined: Jul 2008
Posts: 255
Likes: 0
Check all the grounds especially to the data port. Start ohming wires using the pin out diagram. Check for spark, fuel pressure, have the ICM tested at a parts store, check your coils resistance, clean your IAC and MAF, check your fuses, maybe just fouled plugs from running rich, and unfortunately don't rule out the opti. Just throwing out ideas. Just got done tracking a bunch of problems including running rich at times, not starting when warm, idleing high etc. It was a combo of problems on startup, one was a small wire, one the IAC, and the major one...the opti? Good luck, but whatever you do carbs suck for daily driving, don't go backwards...why do you think all the carb guys drool over injection. It is worth the troubleshooting.
thanks i will check all but the maf sensor since i dont have one but what would cause ecm to not communicate with the scanner and laptop besides having a wacky ecm?
and the car is going to be my strip car i use the c5 for a dd in the summer so i dont mind going to a carb setup but i hate not being able to fix this efi problem!
and the car is going to be my strip car i use the c5 for a dd in the summer so i dont mind going to a carb setup but i hate not being able to fix this efi problem!
Launching!
Joined: Jul 2008
Posts: 255
Likes: 0
A bad ground #1, a bad power wire, or communication wire. Find a pin out diagram for your model, pull the connectors at the computer and check the resistance on the related wires. Remember that looks good means almost nothing when dealing with electrical gremlins. Make sure you have the ignition key in the run position when using the scanner, and also test your scanner on another rig to make sure it isn't the problem. I would suspect the ecm last it is probably a simple little problem that is hard to find.
ok i have mitchell on demand i should be able to get a pin out diagram and the scanner i use on my gn with the gm1 adapter and almost everyday on obdII cars so i dont think thats it. but thanks for the help i will check all the above as soon as i can thanks!
well im not sure why but the car fired right up today.... so tonite when i get out of work i will try to hook the scanner up to it and check for a bad ground/loose wire somewheres
