Hi everyone. guess i should give some background on this beast since im new here. Originally picked up this 95 4x4 auto with 4.3 to replace the under dash wire harness in our 96. I get it home and wife decided she likes the 95 better... one big problem, engine problems! fast fwd a bit... I find a decent engine for it, use all the good sensors and components off the 2 and install...

So here we are today.. It will crank until the battery is dead but it will not fire. I checked all voltages and ohms on all things related.... all good. Even went so far as to replace the fuel injector since it showed 0.00 ohms but was working on old engine. New injector shows 2.4 or so ohms unplugged and sitting in intake. plug in harness and check outside on that harness and get same reading. On the harness side of this I have battery voltage and trigger signal as long as its unplugged....
As soon as you plug in harness and turn on key there is o voltage, no trigger signal and no ohms.

Ive read oil pressure switches have caused issues.. this one is brand new as well...broke old one pulling engine. OH, fuel pressure is 62psi on prime and doesnt hardly drop at all if left sitting.

I have checked for spark, triple checked timing, checked coil, cleaned and recleaned batt terminals, checked all visible grounds and swapped crank trigger with no changes in symptom.

does anyone have any thoughts, suggestions, ideas? I'm pretty well stumped at this point.

planning on rechecking grounds tomorrow (crapshoot not sure what else to try kind of move)

thanks in advance for reading this long post and hopefully for someones input!

 

If you spray some quick start in the intake will it run?

Also, did you use the original PCM? or did you use the PCM from the new engine? if so then you have to have that PCM tuned for your VIN # or else it wont start. And if you used the 95' PCM with a newer engine i believe there might be a problem with that as well but im not entirely sure. Hopefully someone will chime in.

 

Im not a big fan of spraying into intake just to see if it will start... technically it should though. might try it after i check the grounds tomorrow. worst that can happen is it catches on fire right?!?!?!?!

as far as pcm question... i used my pcm, intake, sensors, coil, dist.. etc. but donor engine was also a 95 optioned identical so shouldnt be a problem there... but maybe im mistaken. perhaps someone who has more knowledge on the subject can chime in.

now i need to build a v8 s10 to take my frustrations out on at the track LOL

was doing more reading and came across passlock problems... question, did 95 use any sort of passlock and how would i reset it?

 

I was also thinking about that but i thought the passlock was 98+ but i could also be wrong. But you can always try the procedure to reset it. do a search on google for s10 blazer pass lock

 

yep google shows a couple different procedures but all the comments are 98+
the thing that led me to that in the first place was while i was waiting for the new injector i went ahead and installed a stereo since there was not one in it.
It's just crazy that I drove the thing into my garage with the exact setup thats on it now (minus different block and heads) and of course a stereo and now there she sits!

Just finished making an injector noid light from spare parts so i can "see" instead of watch a volt meter.

will try the passcode reset and check out my noid light later on today.
My gut today is telling me "ignition control module" so will see if napa or oreillys can test it for me tomorrow.

so tonight using the test lights and voltmeter I verified crank sensor is good for sure. got mixed results using diy methods of testing coil and control module and still no injector pulse.

tomorrow will have coil and module tested on "the machine" lol
gut still says control module....

so until tomorrow....

coil bench tests fine.... and both control modules i have tested good. Really starting to wonder what the heck is going on with it.

is it the sensor in the distributor that sends the signal to fire injector, or is it the control module on the back of the coil?

 

Throttle body cleaner sprayed through an intake while cranking is ok on OBD 1 engines, are you loosing spark or fuel?

 

ive got spark at coil and plugs... have 62 psi on rail and its obd2 but it will fire and run for a couple sec's with a shot of carb cleaner.

verified crank sensor, coil and control module are all good... im down to the sensor in the dist or ive developed a short.
i drove it into the garage, swapped bottom end out and bang! LOL seems to be the way my luck is running lately.

anyway, gonna swap out that dist sensor tommorow and hope she runs.

swapped out the cam sensor or whatever its called in the dist. checked all connections again and still nothing.

anyone have a good wiring diagram for the 95 so i can trace these wires down and find this gremlin?? its OBD2 with the EDI ignition or the horizontal towers on cap.

any help is apreciated.

 

have the icm checked out.

 

If what you're calling the ICM is what I'm calling the control module... have 2, had both checked at oreillys and both are good.... and have tried both!
just came in from exploring some more and think I might see a broken ground on the back of the head. really really hard to see and will have to go at this from a couple angles but will see for sure whether its good or bad soon enough.

 

icm is the ingtion control modgule. and if all the grounds are dont hooked up then ur truck mostlikely will not run rite. r u sure u cane take parts off of a 1995 and use them on a 1996. im thinking 1995 was the wonder years for gm. cam senor has to be relearned.