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1989 Blazer has spark but no injector pulse

Old 10-17-2018, 06:58 AM
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Default 1989 Blazer has spark but no injector pulse

I know this probably comes up every other day, and I've read a ton of posts on multiple sites trying to figure this one out. I have a 1989 Blazer Scottsdale, 5.7 TBI. I don't have injector pulse. Here's what I have tried so far:

The first thing I did was pull the ICM to have it tested. When I pulled the cap, though, I found the reluctor and magnet rusted pretty bad and kind of loose. The wiring to the ICM was very corroded. So, I put in a new reman distributor. Still no injector pulse. I know it could be possible that the ICM could be bad right out of the box. Hoping to avoid buying another.
Pulled fuel line after the fuel filter - fuel came out, filter not plugged.
Fuel pump runs for 2 seconds when turning the key on, and it runs constantly during crank.
I have spark to all 8 cylinders.
12V present at coil and at distributor.
Pulled 4 pin connector from ICM, tapped the purple/white wire with a 12V test lamp. This caused the injectors to click.

Ran through the below (Found on both another forum and this one)
1988 K5 Blazer 5.7l TBI will not run - need help!!

On B2 there should be a 2 second on with key on even if you don't go to crank, as soon as you turn to crank it should again have power. Tests Good.

Then if there is a crank signal to C9 when key is cranked the fuel pump trigger at A1 turns relay back on and looks for the signal again at B2. Tests BAD. Volt meter shows no voltage with key off, on, or in crank. What does this mean??

Do you have power at Orange wire B1 and C16 Batt Power? Key off, key on, key Crank? Tests Good.

Do you have power at Pink wire A6 Ignition, should be hot key on and key crank?
Tests Good.

So, what does this mean? No signal at C9? ECM or something else? I don't like throwing parts at a car to figure out the issue. I ordered a set of noid lights so that I can test the injectors this weekend.

Some other symptoms that may or may not be related, and lead me to think there is a bad ground in the back possibly:
Fuel gauge is pegged at full when the key turns on.
I only have a passenger side brake and turn signal light. All other lights do not work in the back.

Last edited by jkohnz; 10-17-2018 at 07:00 AM.
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