94 GMC Suburban Cranks without starting

Can I check the engine timing without starting the vehicle?

I would very much appreciate that. I have had nothing but problems with the truck since I got it. Things were going good for a little while than this. Of course it can’t be something simple. If you can tell your friend I am seeing spark going to all 8 cylinders. There appears to be fuel as I see spray from the injectors when the relay is plugged in. When I unplug the relay the fuel stops but the truck seems to attempt to start with the relay removed. If I feed it starter fluid it runs off that sometimes but its tricky to get it to stay running. It seems very particular about how much I spray. Too much stalls it and so does too little.

If I plug the fuel pump relay back in, it almost acts like the fuel is flooding it out and it doesn’t even attempt to start.

Please someone help, this is my daily driver and I have to be at work tomorrow

[quote=”college man” post=55783]see if this helps you.

http://www.justanswer.com/chevy/1xliv-1994-suburban-randomly-run-fine-fuel-pump-relay-it-doesnt-start.html%5B/quote%5D

Thanks for that information. Here is what else I found this morning. I leave the fuel pump relay plugged in so its getting fuel. I disconnected one of the injectors and cranked it over. Truck starts up, I have to keep feeding it gas for the first few seconds and than after that it idles on its own but its idling rough. While the trucks running, I reconnect the disconnected fuel injector and the idle immediately speeds up and smooths out. Truck runs normally at this point. All gauges are working on the dash EXCEPT for the oil pressure gauge. It is staying around 50 no matter the engine speed.

This gauge used to read around 20 at idle and would go up around 40 while cruising. It would vary with the engine RPM. Now it is just stuck at 42 or whatever and is not moving at all with the RPMS.

I used a test light and checked for power at the pigtail with the pigtail unplugged from the sensor. The red or orange wire lit the test light bright. The other connection was showing ground and the top prong showed nothing until the ignition was turned on and than the test light illuminated dimly.

Hopefully this helps narrow down the problem and someone can steer me in the right direction. Seems like the injectors are spraying too much fuel upon start up and flooding engine out. Once one inj is disconnected the engine starts and the other injector can be plugged back in and the truck runs as it always did. I did just replace both the engine coolant temp sensor and the engine temperature switch when I did an intake manifold gasket job on this truck a month or so ago. Also the temperature gauge in the truck does appear to work.

Also I think the code 54 was because of the intermittent wire connectivity issue shown in my video on the prior page where I showed how one of the fusible links was breaking and corroded. When I probed the wire, it was not getting voltage after the fuseable link. It is a red wire that hooks into the convenience center close to where the fuel pump relay is so I believe this is the cause of the code 54. By the way, since I jumpered the wire as shown in the video, the CEL did not illuminate when the truck was running. I will try getting the wire to loose signal again and see if it brings back the code 54 again.

[quote=”Zirrer” post=55792]i can’t find the video your talking about im new the the form is there a link im missing ?[/quote]Here is the video. If you skip to approximately 1:54 of the video you will see the wire I am talking about

https://www.youtube.com/watch?v=bvniCl68Zmk

I disconetted the pigtail that goes to the oil pressure sensor and put a volt meter on it. The red wire shows 12 volts constant. The top wire shows approximately 8 volts when the engine is cranking. I had to disconnect the pigtail from the sensor to test it, its too tight of a fit to test it with the plug connected.

I don’t have a fuel pressure tester.

[quote=”Zirrer” post=55800]ok I figured out why I couldn’t see any videos (unsecure Script on the forum) now when you crank does the voltage drop below 9 volts if so I would try jumping or a charger on it and let it get charge
as for the fuel filter even if there is fuel to the injectors it may not have enough flow or volume to run[/quote]

I just rented a fuel pressure tester and installed it per the manual right after the fuel filter with a t fitting. Its showing both 12-13 PSI of pressure both upon turning the key on and the car running. If you turn the key on and leave it on without starting the car, the pressure goes up to 12-13 psi and then drops to 0 once the pump stops running. Also since I bypassed the fuse on that bad wire near the fuel pump relay, the code 54 is no longer showing. However the car still wont start unless one of the injectors is unplugged. I have a video showing the readings Im getting uploading now. Will post once its done. Fuel pressure regulator allowing the injectors to get too much fuel at the same time maybe? From what I have seen 12-13 psi is normal and the pump is therefore good. Not sure if its normal for the pressure to drop down to zero once the pump stops running though.