wow what a puzzler... wrap your minds into this. okay I just bought a 92 pro dx with a sohc and 5-speed... the motor was replaced last year and the thing purrrrrrrrs like a kitten when it runs... however it doesn't always run... some time it starts right up, other times forget it! I checked and got no spark... so i test the coil, fine so i test the igniter, fine alright maybe the swap went wrong when the new motor was replaced (doubtful because theres been 8k miles since the swap) but i check every damn wire in the hanes manual and all have continuity... I cleaned ALL the grounds related taking it to the engine and nothing... heres the odd part... As soon as i bump the key to "ON" i know if the car will start... IF the check engine light comes on with the key in "on" then it will pop right off... everyother time the check engine light is dead... so im thinking ground to the computer... but the 3? grounds there all have good continuity... and since this is so off and on of a problem... what are the odds that the computer itself went bad?? what else can it be?? I'm open up to ANY input right now...

 

Have you checked the ignition switch ,sound like the switch has a bad contact

 

even though there is power to everything else?? theres 12.xx volts at the coil and at the comp on the white/red wire...

 

you could still have power to them but not to the starter circut

 

still confused... it cranks just fine

 

now maybe im begining to see... i guess the switch has more than one out... and i may have found one that could be shady... If anyone has theres somewhat apart can they check for voltage on the black/yellow wire going into the computer???

 

all continuity is there where it needs to be according to the haynes manual, so the ignition switch checks out...

 

ttt

how likely is the ecu itself to going out?? it has to be computer related because all the wires check out... I pratically ripped the entire enterior apart checking them out....

 

its not the ecu.....



anyone??

 

Check your fuses man. Its the fuses. you havent tried anything else. Theres a fuse in the fuse box for your fuel pressure regulator. (or the fuel pump? i forgot)
its the biggest black fuse in the lower left hand corner of the box.
If the engine is cranking but wont start, theres a good chance that theres no fuel delivery to the chambers if its not the alternator. dunno if you checked that.

 

fuses are all good... just when there is no check engine light on "run" then the car wont start...

 

you may have already tried
but in the diagnoses hook up, put a piece of wire conecting the #10 to the ground and see if any codes come up.

also check the ground wire off the battery. if it has a short every thing could halve the right voltage but short out when you try to start it.(happend to me last week).

 

i tried the test connector, but i don't have a check engine light.... i've seen it light up so i know its not blown... its like the computer is not on...

 

did you check the ignition relay thats by the computer.(the black&yellow thing)
it would be hard to switch out the computer, and at least narrow the problem down.

your not in texas are you??? ive got an ecu not being used right now, but its for a dohc.(not sure if it would work for a sohc)

 

well i swapped in a different ECU and it did absoutley no good ...


now as far as that relay... i was looking at it and checking it out. It has power in going in to it only when the key is at "run" in my mind it should have a constant hot wire along with a hot in "run"
even that being the case I would think it would have 2 hot in "run" wires... otherwise what good is a relay???

and the diagram i have isn't a whole lot of help either... the two bigger guage wires closet to the firewall at the comp both have 12+ volts. one constant the other just in "run" if i remember correctly and i cant see any other in the diagram that should have power...

so i'm still hooked on it being a ground to the comp... tomarrow if i have time i'm running jumpers off the 4 grounds, directly to the battery and seeing if that makes a difference... if not I'm pulling the entire wiring harness and checking every frickin wire!!!