so my car back home is having no start issues. its a 91 with an ls so its obd0.
heres the issue: no spark and no fuel but cranks strong, soild CEL with no code even when jumped.
heres the twist: MFR, ignition, distributer and ecu (which is a chipped p28) have all been tested in another da and confirmed to be 100% working. they were tested individually and together. all grounds have been checked as well. when cranking, the tach doesnt jump at all, the fuel pump doesnt prime, and it just makes the sound of the starter turning the motor. no ignition at all. theres also no power getting to the ecu.
reading all over the internet, all the no spark no fuel issues ended up being faulty parts that are listed above. obviously these parts are not faulty in my car since they have all been tested in a another da and they work. all the trouble shooting i have read about is wrapped around finding which of the above parts are faulty.
all fuses and relays have been checked, there is no alarm installed in the car.
another thing i should mention, im using obd1 jumper harnesses for the ecu and distributer and the harnesses are good as well.
literally stumped on this one… anyone have any suggestions?
i had this same problem with a 92 LS a few years back… the most logical thing i would think it could be is your crank sensor. after everything you just explained that would be th next thing i would look into because its the only other thing i could think of that plays a part in fuel and spark
the ckp is incorporated into the dstributor. but if the pump doesn’t prime, it’s likely not the issue.
you said you don’t have power to the ecm? a wiring diagram is necessary to find out why. how did you check the fuses? eyeballing is not enough. you must use a meter, or at least, test light.
matter of fact, how do you know the ecm has no power? which power is missing? constant? or keyed? did you check with a meter? if so, the only 3 things you need to solve this are a dvom, ecm pinout, and engine controls wiring diagam
Well, im back home visiting and I was able to fumble with the car. I fixed it. Im not 100% sure which of the things I did fixed the issue but I will list what I did and anyone who has an issue like this in the future can do what I did.
-replace any blown fuses on both boxes and make sure all the correct size fuses are where they are supposed to be
-make sure the thermostat ground is clean and attached properly
-make sure the ground from the valve cover to the chassis is there, clean and correct
-make sure the ecu plugs are fully seated and the ecu is good. Open in and inspect thr board on BOTH sides.
-if you have any custom wiring or whatever, make sure its still connected and that the wires haven’t separated or something
This turned out to be a bad ECU. Checked it with a b20 ECU and it started right up. Something in the ECU was preventing the fuel pump from priming. Purchased a new ECU and works fine.
I tried replacing bad capacitors within the ECU, and also using a board cleaner but neither of these worked.