Engine turns but will not start

Good afternoon,

What was the compression?

If you have spark and fuel pressure, did you check the actual pressure, then it is not a module or ignition switch.

https://www.2carpros.com/articles/car-cranks-but-wont-start

Roy

Update: adding some more information.

I got a better crank after letting it sit overnight, so at a certain point it is getting flooded with fuel from trying it.

Also, I unplugged the connector from the computer to the ignition control module and it started up but was pretty weak and shut off after a couple seconds. I tried it again plugged and unplugged ICM and the truck started up with it unplugged for a few seconds.

Does not make any sense if you unplugged the module. It would have no spark and will not run.

Roy

The ICM has two connections one to the computer and one to the ignition coil. From what I understand the spark should not be affected by unplugging the ecm connector.

Does that mean anything aside knowing that the icm is working?

I know how the ICM works. Yes, it is effected by unplugging the ECM.

You very well may have a bad ECM. Common on the OBD1 series. That is the only thing that makes sense here.

Roy

Thanks for your help so far. I will start looking at fuses/relays first then wiring as far as I can follow to see if that could be making the ecm not work properly.

Diagram for you of the ECM.

Roy

Update: Truck still wont start on its own, but it will start if I give it some gas as it turns.
Idle is very weak it almost turns off but it'll maintain when I step it on the gas it reacts on time. There is a code but I am lacking an OBD1 and the old paper clip trick isn't working.

Okay, from your description, it sounds like the ECM has failed. It controls the injectors and could also be the reason you cannot get it to communicate.

Roy

Replacement of the Electronic Control Module (ECM) consists of a service controller, without a PROM (CAL-PAK).

If the diagnostic procedures require the ECM to be replaced, the ECM, PROM (CAL-PAK) should be checked for the correct part number. If they are correct, remove the PROM (CAL-PA K) and install them in the service controller. The service controller will not contain a PROM (CAL-PAK).

IMPORTANT: When replacing a production ECM with a service controller, transfer the broadcast DTC and production ECM part number to the controller label. Do not record information on the access cover.

NOTE: The ignition must be "OFF," when disconnecting or reconnecting the ECM connector, to prevent internal damage to the ECM.

NOTE: To prevent possible Electrostatic Discharge damage to the ECM, Do Not touch the connector pins or soldered components on the circuit board.

REMOVE OR DISCONNECT
1. Negative battery cable.
2. Glove box panel.
3. Mounting brackets and/or retainers.
4. PCM from tray.
5. PCM harness connectors.
6. Access cover and PROM (CAL-PAK).

INSTALL OR CONNECT
1. PROM (CAL-PAK) and access cover on new PCM.
2. Mounting brackets and module(s).
3. PCM into tray until clips lock.
4. PCM harness connectors.
5. Glove box panel.
6. Negative battery cable.
7. Perform functional check.

I did run a fuel pressure test and got 11 psi going to the injectors. It looks like the pump checks out and will start looking at the ECM.

Okay.

Roy

Late Update:
The ECM was the problem. Bought a used one off of ebay and swapped in the prom chip and the truck feels as good as new. It might have fixed up some other issues also, it feels like it is shifting a lot smoother.

Symptoms:
-Crank but no start (fuel,spark, and compression checked out).
-Eventually started by stepping on the gas while cranking.
-Low idle under under 500 RPM.
-Engine would rev but once I let off it would die out or almost die out the return to the 500 RPM.
-Noticeable loss of power when taking off from a stop.
-Check Engine light was ON but would not show the code.

Hope this helps anyone who is going thru the same thing.
Thanks for the help asemaster.

Sounds like the idle air control on the throttle body. A common failure for all those symptoms.

Roy