Engine cranks but will not start

1995 GMC C1500

270,000 MILES • 5.0L • V8 • 2WD • AUTOMATIC

JWAINBAMA

MEMBER
1 POST

I can turn the engine over but want start . It has spark , fuel pump is working and new inline fuel filter . Also put new fuses in . Also new distributor cap and rotary button. Spark plugs and wires . I had friend turn it over and I see no gas in carburetor. I can pour gas in carburetor and it cranks and runs as long as gas is being poured in slowly. As soon as I stop pouring it in it shuts off. What do I do now?

Aug 10, 2021 at 7:28 AM

SQM

✓Experienced Mechanic
6,383 POSTS

Hello,

It sounds like the engine is not getting fuel.
As you mentioned the pump is good, it could be the cause of a faulty fuel pressure regulator or a clog in the fuel line.
Check to see if you are getting adequate fuel pressure.
Another possibility, this pump has a pulsator, the pulsator is a flexible connector between the pump and the metal fuel line in the tank. If there is a rupture in that line you will have no fuel pressure. You will hear the pump come on but it will not produce any pressure.
The pulsator tends to rupture is there are excessive amount of ethanol in the gasoline.

First step would be get the pressure checked.

https://youtu.be/aITQclp7zIE

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

If you have low to no pressure check the regulator. If the regulator is good then it could be the pulsator.

Please let me know of any questions.

Thank you.

Images (Click to enlarge)

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

Aug 11, 2021 at 6:13 AM

Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.