Will not start

BOULDERSKIES

MEMBER
1995 GMC SUBURBAN
5.3L
V8
4WD
AUTOMATIC
200,000 MILES

My SUV will crank. It is getting spark to plugs.A bunch of parts have been replaced including the ignition switch. The tell-tale clue is the fuel pump (just replaced) will run for about six seconds and then quit. Therefore no gas is getting to throttle body carburetor.

Does this sound like the fuel pump or an electrical problem?

Thanks for everything you guys do.

Scott

7 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Good morning,

While the engine runs, the fuel pump cuts off?

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

Can you verify the engine size? No 5.3 listed for 1995.

It should only run for two seconds with the key on.

Do you have spark?

Does it start right back up when it shuts off?

Roy

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Friday, May 24th, 2019 AT 5:22 AM

BOULDERSKIES

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20 POSTS

It is a 350. Sorry, I didn't know the exact size in liters. The fuel pump runs for about six seconds with key on, engine not running. Normal? Yes, have spark. Engine doesn't run at all, just cranks.

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Friday, May 24th, 2019 AT 5:58 AM

ASEMASTER6371

MECHANIC
52,797 POSTS

Thanks.

That is normal. It should stay running while cranking.

Can you check the fuel pressure?

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

Also, I would check the compression to be sure the timing chain is good.

https://www.2carpros.com/articles/how-to-test-engine-compression

Roy

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Friday, May 24th, 2019 AT 6:15 AM

BOULDERSKIES

MEMBER
20 POSTS

Thank you for your quick replies. Here's another clue: If I spray starter fluid into the carburetor, the engine fires right up. Does that change your last reply?

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Friday, May 24th, 2019 AT 7:19 AM

ASEMASTER6371

MECHANIC
52,797 POSTS

If it starts with fluid, it is a fuel delivery issue.

It could be either the fuel pump itself, the ECM which controls the injectors or the injectors themselves.

Roy