SPONSORED LINKS

Cranks but no start

Tiny
JUNIORDRITSAS
  • MEMBER
  • 1993 CHEVROLET 1500
  • 5.7L
  • V8
  • 2WD
  • AUTOMATIC
  • 126,000 MILES
Hello, one morning went out, truck would just crank, I changed the fuel pump relay, truck started after stepping on the pedal, then it was good all week, after the week it did the same thing all over, just would crank. Any help would be appreciated. Oh yeah, when the key is on, the oil pressure gauge moves around a little.
SPONSORED LINKS
Thursday, September 16th, 2021 AT 5:55 PM

26 Replies

Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
Hello,

Can you hear the fuel pump with the key to the on position?

If you can hear the pump then you need to see if you have fuel pressure. In case a faulty regulator is causing the issue.
You should have 9-13 PSI of fuel pressure with the key on and engine off.

https://youtu.be/aITQclp7zIE

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

Let me know what you got.

Thank you.
Images (Click to make bigger)
Thumb
Thumb
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Thursday, September 16th, 2021 AT 9:33 PM
Tiny
JUNIORDRITSAS
  • MEMBER
  • 14 POSTS
Yes, I can hear the fuel pump from the tank with the key on.
Was this
answer
helpful?
Yes
No
+1
Friday, September 17th, 2021 AT 8:00 AM
Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
So if the pump is coming on then you need to check the fuel pressure. If the pressure is low then you could have a bad regulator or could be a restriction in the line.

Have you already checked to see if you have spark?
Was this
answer
helpful?
Yes
No
+1
Friday, September 17th, 2021 AT 9:35 AM
Tiny
JUNIORDRITSAS
  • MEMBER
  • 14 POSTS
Checked it today, I do have spark on number 1 plug.
Was this
answer
helpful?
Yes
No
Sunday, September 19th, 2021 AT 7:22 PM
Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
Make sure you are getting fuel. It should be 9-13 PSI with the key on and engine off.
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Sunday, September 19th, 2021 AT 7:44 PM
Tiny
JUNIORDRITSAS
  • MEMBER
  • 14 POSTS
I was told that the ignition control module controls the injectors, is that true?
Was this
answer
helpful?
Yes
No
Sunday, September 19th, 2021 AT 9:16 PM
Tiny
JUNIORDRITSAS
  • MEMBER
  • 14 POSTS
It doesn't seem to be getting fuel, have buzzing from the tank from the fuel pump though.
Was this
answer
helpful?
Yes
No
Sunday, September 19th, 2021 AT 9:18 PM
Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
The ignition control modules provides spark to the plugs, it does not control the fuel pump or fuel flow.

So you said you can hear the pump with the key to the on position?
If the pump is coming on but you do not have proper pressure, it could be due to a clog in the line, could be a fuel filter that is jammed or a bad regulator.
Was this
answer
helpful?
Yes
No
Sunday, September 19th, 2021 AT 9:37 PM
Tiny
JUNIORDRITSAS
  • MEMBER
  • 14 POSTS
What exactly does the fuel pump relay do?
Was this
answer
helpful?
Yes
No
Monday, September 20th, 2021 AT 10:54 AM
Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
The fuel pump relay provides power to the pump. If the relay is bad then the pump will not get any power and will not turn on. So if you can hear the pump come on the relay should be good.
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Monday, September 20th, 2021 AT 11:08 AM
Tiny
JUNIORDRITSAS
  • MEMBER
  • 14 POSTS
What's weird is what I started out with, wouldn't start, then I changed the fuel pump relay then it started, but only lasted a week.
Was this
answer
helpful?
Yes
No
Monday, September 20th, 2021 AT 12:35 PM
Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
Interesting, so on the last time did you hear the fuel pump come on?

Have you got a chance to check the relay this time?
Here is a way to test the relay just in case:

https://www.2carpros.com/articles/how-to-check-wiring
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Monday, September 20th, 2021 AT 12:48 PM
Tiny
JUNIORDRITSAS
  • MEMBER
  • 14 POSTS
Yeah, I couldn't find where testing the relay was at on the page.
Was this
answer
helpful?
Yes
No
Monday, September 20th, 2021 AT 1:53 PM
Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
Sorry about that. I have sent you the wrong link. Try this please:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Thanks.
Was this
answer
helpful?
Yes
No
Monday, September 20th, 2021 AT 2:58 PM
Tiny
JUNIORDRITSAS
  • MEMBER
  • 14 POSTS
Yeah, I just went out and squirted some gas in the carburetor, I get nothing.
Was this
answer
helpful?
Yes
No
Monday, September 20th, 2021 AT 4:01 PM
Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
If spraying fuel does not start the engine, then you might not have spark. As you know the two of the basics for engine start is spark and fuel.

Do you know if you are getting spark to the plugs. You can just pull one of the plugs and crank to see if it sparks.
And also if your pump is coming then it should be getting some fuel.

Lets take a step back, let me know what you have tried so far, this way we can figure out the next best step.
Was this
answer
helpful?
Yes
No
Monday, September 20th, 2021 AT 9:48 PM
Tiny
JUNIORDRITSAS
  • MEMBER
  • 14 POSTS
Well, I went out and bought a cap and rotor, ignition control module, going to put them in today.
Was this
answer
helpful?
Yes
No
Friday, September 24th, 2021 AT 11:21 AM
Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
Let me know how it turns out.
Was this
answer
helpful?
Yes
No
Friday, September 24th, 2021 AT 12:27 PM
Tiny
JUNIORDRITSAS
  • MEMBER
  • 14 POSTS
Sorry for the delay, but kind of stayed away from the truck for some time, today I swapped out the fuel relay, got it running, but went out a hour later, no start, only when I stepped on the gas pedal.
Was this
answer
helpful?
Yes
No
Tuesday, October 19th, 2021 AT 8:52 PM
Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
So, what is it doing now? Does it just carks over and not start?
Can you hear the fuel pump kick in?
Was this
answer
helpful?
Yes
No
Tuesday, October 19th, 2021 AT 9:01 PM

Please login or register to post a reply.

Related Engine Not Running Content

Sponsored links