Crank, no start?

1998 GMC C1500

90,000 MILES • 5.7L • V8 • 2WD • AUTOMATIC

TOTALMC

MEMBER
117 POSTS

Turns over strong and almost fires, but doesn't.

I've run most tests I can think of.

Spark tester shows spark.
Fuel pressure 60 PSI.
Power and ground signal at injector harness.

I can get it to run on spray through the throttle body, so I'm assuming its fuel related.

All I can think of is a fuel pressure regulator, which is down next to the spider injectors underneath the manifold, but would not want to tear that all apart if that's not it and I'm missing something.

Any ideas are greatly appreciated.

Thanks in advance.

Sep 16, 2022 at 10:02 PM

STRAILER

✓ASE Certified Mechanic
54,832 POSTS

Yep, I was going to say spider injector which they had problems with, the new unit from AC Delco has been updated so they work better FYI. Here is how you can change the spider out to fix the problem, also I would install new spark plugs when you do the repair. Check out the images below to see how the repair is done.

REMOVAL PROCEDURE

CAUTION: Use care in removing the fuel injectors to prevent damage to the electrical connector terminals, the injector filter, and the fuel nozzle.

NOTE: The fuel injector is serviced as a complete assembly only.

CAUTION: Also, since the injectors are electrical components, these injectors should not be immersed in any type of liquid solvent or cleaner as damage may occur.

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to Fuel Pressure Release Procedure.
3. Remove the Upper Manifold Assembly. Refer to Engine Mechanical.
4. Remove the Fuel Meter Body Assembly. Refer to Fuel Meter Body Assembly.

INSTALLATION PROCEDURE
1. Install the fuel meter body assembly. Refer to Fuel Meter Body Assembly.
2. Install the upper manifold assembly. Refer to Engine Mechanical.
3. Connect the negative battery cable.

Check out the images (below). Let us know what happens and please upload pictures or videos of the problem.

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
Click here to log in and view diagram.

Sep 17, 2022 at 10:32 AM

TOTALMC

MEMBER
117 POSTS

Ended up being a security issue.

The customer previously installed security bypass, I think he then removed it and the truck started right up.

Not sure why I had a signal at the injectors, and spark. I thought the security system disabled those systems.

Sep 21, 2022 at 3:22 PM

STRAILER

✓ASE Certified Mechanic
54,832 POSTS

Thanks for getting back to us. Nice work on fixing it, we are here to help, please use 2CarPros anytime.

Sep 22, 2022 at 12:08 PM