HELP no spark

[AuroraGirl]

Did sbc ever change firing order like fords did in the early 90s?I dont think your firing order is wrong but im just checking

I do know one thing tho, if you didnt make the 91 a roller cam, you need a different gear on your distributor end
Also, Im guessing heads came along because GM most definitely changed some things like spark plugs and design of various things lol

I would see if there is anything that would inhibit spark. i dont know how the sbc did it late in the 90s, but like my 3800 if you dont have reluctors pass remotely in the right count or order the ICM wont even allow the car to ever start because it needs to see a sequence first to know when to control injectors/spark etc......
but i doubt its going to be as complex as that, i just say if its anything like reluctors.... or if you missed any important grounds

 

[GavinJansma]

Better than nothing.

What I meant was for you to connect a scan tool, and verify that the computer sees an RPM signal from the crank sensor. From there, you can verify all the other sensors as needed, but of course you'd want to concentrate on the ignition system--cam sensor offset with the scan tool; ignition coil and module power using a test light or voltmeter. You should be able to verify that the module is at least partway working by looking at the dwell during cranking. If you have no dwell, you've got problems in the module, wire harness to the computer, the computer itself, or the signal from the crank sensor.

If you have dwell but no spark, you've got problems in the ignition coil, or the wire harness to the coil.

I have this really nice ass multimeter I dont know how to use that I bought a while back if you would be able to tell me how to use it to test individual parts I think that might help.

 

[GavinJansma]

Did sbc ever change firing order like fords did in the early 90s?I dont think your firing order is wrong but im just checking

I do know one thing tho, if you didnt make the 91 a roller cam, you need a different gear on your distributor end
Also, Im guessing heads came along because GM most definitely changed some things like spark plugs and design of various things lol

I would see if there is anything that would inhibit spark. i dont know how the sbc did it late in the 90s, but like my 3800 if you dont have reluctors pass remotely in the right count or order the ICM wont even allow the car to ever start because it needs to see a sequence first to know when to control injectors/spark etc......
but i doubt its going to be as complex as that, i just say if its anything like reluctors.... or if you missed any important grounds

I've triple checked grounds

Negative
Battery to fender
Battery to block
Battery to frame
Frame to firewall
Frame to block
Wiring harness to intake

 

[GavinJansma]

Update I am getting spark going to distributor just not coming out... changed cap,rotor and distributor still nothing...

 

[Schurkey]

Update I am getting spark going to distributor just not coming out... changed cap,rotor and distributor still nothing...

"Not coming out" or "not coming out at the right place"?

If the distributor is installed wrong, the rotor won't be pointing the right way, or the rotor-to-cap alignment will be way off.

 

[AuroraGirl]

I've triple checked grounds

Negative
Battery to fender
Battery to block
Battery to frame
Frame to firewall
Frame to block
Wiring harness to intake

do you have a block to chassis(firewall)

By intake do you mean your PCM ground? Can I see?

 

[Macs Garage]

Since you are going through engines, are you flushing the oil cooler when replacing the engine? I didn't and metal from the previous engine failure took out the replacement engine. Now I have a new GM engine in my truck. GM will not warranty the engine if the radiator which contains the oil cooler is not replaced.

 

[Ruff Idol]

May have fried the ignition control module (little unit behind the coil, not too easy to spot on first glance). It's held in by 2 bolts and pretty easy to change, may want to do this if fuses are good and you are sure the coil is getting correct voltage.