Drove it. Parked it. Then no start. Pulled the coil rail and left all 4 plugs in, all 4 got spark. Looked fouled though so replaced plugs. Fuel pump kicks on. Tested pressure. Key on engine off got about 45psi. Checked all fuses in engine bay box. Checked for power at all fuses in engine bay, all got 12v. Used the screw driver method for injectors. All are clicking. No dtcs. All lights work.

With no codes I'm a bit lost. First ideas would be crank sensor, but with no codes and getting spark I'm not so sure. Or the ignition module is giving spark but not correctly? Spark is bright blue/white.

 

fuel pressure should be at least 55 psi

https://www.fixmyoldride.com/Chevy-C...fuel-pump.html

 

Might have been up to 55. Just turned the key on an off a couple times but didn't wait to see it it would keep climbing. Cranking it over the pressure was at 50-55 for sure. Also sprayed starter fluid in the intake and got nothing.

 

the article says ABOVE 55 PSI, not up to.

 

Fair enough. Just rechecked it's at 52. Any one have the crank sensor information to verify that's working, before I replace the fuel filter then pump?

 

You can check the sensor with either a vom. Continuity at the connector to the sensor, I am guessing around 1K ohm. Cranking you should read a/c voltage, varies, but you should read some small voltage, not mili volts, should be greater than that.

 

Crank sensor. The plugs are firing, but randomly.

 

Replace crank sensor. Not it. Tested throttle sensor, read correctly. Spraying starting fluid does nothing. Will start/fire with wide open throttle, anything less it stops firing.

Ideas?

 

Pour a small amount gas directly down the intake and hit the starter - if nothing happens you've got an ignition problem - if it runs for a few seconds and dies you've got fuel supply problem. (If it didn't fire on the starting fluid though, you've prolly got an ignition prob...)

Check all the grounds - on an old car, poor grounds due to corrosion can cause all sorts of bizarre problems.
Next would be engine management computer?... PCM it might be called. - Maybe pull out the injectors, crank the engine and see if they're injecting properly (see YT video) - carefully inspect wiring loom

On my car, I was getting great spark but the crank sensor was NG so the sparks were mis-timed.
good luck

 

Got a used igniting module from the junk yard. Same issue. If the car sits, when I first turn it over it fires a bit then nothing, unless the throttle is full open. I remember way back someone mentioned when WOT the injectors either spray full or don't spray at all. Ideas on that?

I'll pull injectors and check, and also pull the plugs to confirm they aren't fouled even thought I just replaced. Who knows maybe they've fouled due to a bad injector or something. Any one know how to check the timing? Figured it's worth a shot if the chain jumped or something. But I'm not getting any rattling or other wise weird noises.
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