1994 4.3 vortec cps location

My 1994 4.3 vortec in a blazer is dying at idle. Mechanic said the cps is bad but don't know where to find it.

My 1994 4.3 vortec in a blazer is dying at idle. Mechanic said the cps is bad but don't know where to find it.

The injector is in the upper intake.
But proper testing first before throwing parts at it.
What did the mechanic say was bad on it?.
What is it doing or not doing?
Does it have proper fuel pressure?

It dies at a stop or low idle. It is hard to start back up usually. When it is running it runs good. Good fuel pressure. Mechanic said it showed on his computer it lost signal with the crank.

It dies at a stop or low idle. It is hard to start back up usually. When it is running it runs good. Good fuel pressure. Mechanic said it showed on his computer it lost signal with the crank.

It does not have a crank signal or sensor.

What was the code no and what was the fuel pressure reading?

Are you saying this motor does not have a crank position sensor? On the fuel pressure I think it was 65lbs but not sure. I got a cps at O'Riellys and they told me it was on the front of the motor below the timing cover but its not there.

Are you saying this motor does not have a crank position sensor? On the fuel pressure I think it was 65lbs but not sure. I got a cps at O'Riellys and they told me it was on the front of the motor below the timing cover but its not there.
Well maybe it does not have one or you did not find it.
S-10 Blazer no. THEY DO NOT HAVE ONE.
Big Blazer code yes.
What engine code and what Blazer?
What was your code no?

Sorry it is a S-10 Blazer.

Sorry it is a S-10 Blazer.

Sorry it is a S-10 Blazer.

I do not show a crank shaft position sensor for the S-10 Blazer.
Does it have the new style flat top dist or code w engine?
What code no did he get on scanner?

The '94 does not have a crank sensor and has the reguler HEI system, the top mounted spark plug wire cap. What does it do when it stops running? Does it stumble or just cut out? Are you/your mechanic sure you are not reffering to the CPI (central port injector)?

Yes it has the top mount spark plugs. It is a "W" motor.When it dies it just quits no stumble. I replaced the injector controller under the intake. It did run good for a while, no dying, but started back the same way in a couple days. I'm not sure what code it showed or what the mechanic saw from his computer.

This could still be a related ignition issue. The ignition control module is located under the cap and can exhibit problems like you mention. These sytems are pretty straight forward, but of course, you have to properly diagnose. When the truck dies out, pull a plug wire off and check for spark, if your getting nothing or a random spark, your ignition module most likely needs to be replaced.

Thanks for all the help. I will do some checking and I hope you are right. I wonder now what the sensor O'Riellys gave me is for? It can go back so itdoesn't matter..

As said the big Blazer has that crank sensor.

Test it when it quits as blazes9395 said.

If good spark then give it a shot of carb cleaner and see if it will fir up.
If so you have a fuel delivery problem.

If you are losing fuel delivery and have good injector pulse check the injector wiring that runs into intake.
I have saw a lot of them with broken wires and bad plugins.
Look at and check the plugin where it plugs onto injector unit real close.

I have good spark but it does not have good injector pulse. How much fuel pressure is it suppose to have?

94 vin Z or H fuel pressure specs is 9 -13 lbs fuel pressure.

How and where and what is not good with your checking injector pulse?

It is a 1994 with "w" vin code. We checked at the port on the back side of the intake by the distributor.

W engine codes fuel pressure specs are 55/61

Here is some guide lines of fuel pressure checking.

Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 55-66 fuel pressure.
Cold start should be 55/62 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 55/62 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
If pressure does not come up with return line pinched or blocked off.
Go to fuel filter and hook a gauge direct to a line at fuel filter.
Pressure should come up to 75 or more and will hold after fuel pump is turned off.
If it leaks down there after fuel pump is turned off it is LEAKING BACK THREW PUMP CHECK VALVE OR PUMP MODULE LINES.
Post back your fuel pressure readings.
MT