How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Vladgmru Your Own Question
Vladgmru, Automotive Electrician
Category: Chevy
Satisfied Customers: 2668
Experience:  I've been working with American made cars since 1992.
Type Your Chevy Question Here...
Vladgmru is online now
A new question is answered every 9 seconds

I have a 1997 Chevy K1500 5.7L (gasoline). Tonight when I

This answer was rated:

I have a 1997 Chevy K1500 5.7L? (gasoline). Tonight when I was driving home it experianced a problem. No abnormal indications on the gages. No abnormal sounds. I swear it kinda hicuped and gradually slowed down. Almost like it was starved for fuel. I could let it sit for a few minutes and it would restart. Again no abnormal indications. Within another few minutes it would die again... Looking under the hood, I noticed nothing. Oil was good. There was condensation in the tailpipes which was clear with no strange smell like oil or coolant. No leaks underneath. Fuel filter was replaced two years ago. I'm thinking fuel pump? Then again I'm not a mech.
My name is Vladimir.
The situation you described could be a fuel pump issue.
The fuel injection system in your truck requires at least 55-60 PSI of fuel pressure.
To be sure that it is indeed the pump problem, fuel pressure must be checked with a special gauge.
You should check the fuel pump relay, it is located in the fuse/relay box under the hood.
Remove it and inspect its terminals for any burned mark.
These relays( and sockets) tend to burn since these fuel pumps draw high current ( about 8-9 Ampere).
Here is the relay location view:
Customer: replied 8 years ago.
The neighbors are going to think I'm nuts... lol

Okay, I have the relay with me. OMRON # XXXXX D00

Five pins total. Two on the diagram side, three on the non-diagram side. I'm looking at the set of three.

The the first pin on the left, as I look at the non-diagramed side, appears to have a burn mark. I can see a small dot of copper vs the silver coloring of the pin. and what appears to be the burn mark above it. The middle pin in this set of three also appears to have a burn mark however, it does not have the copper coloring like the other pin.

I suppose that these pins have nubmers. Isn't it?
The important pins are # XXXXX and #30, they should be clean without any heat damage.
Check the corresponding "female" terminals in the relay socket( fuse/relay box housing), if it damaged as well, you have to replace these "female" terminals or a new relay will burn too.
Customer: replied 8 years ago.
You are correct, we're looking at number 87a (left looking at from the non-diagramed side) and 87 (middle). I'll have to check the female terminals when it's daylight outside. (3 a.m. here).

85 87 87A
86      30

I'll get back to you as soon as I can. If I can find my meter is there an go/no-go for ohm readings?
I think you don't need to use a multimeter.
#87 should have +12 power all time
#30 gets +12 power when relay's contacts close and it feeds the fuel pump
#86 is ground for the relay coil
#85 is the control circuit for the relay coil from the PCM ( Powertrain Control module).
If you jump #87 and #30 "female" pins, the fuel pump should operate.
Do not jump these pins if you are not 100% sure with numbers.
That seems to be a wrong pins legend.
85 87 87A
86 30
Here is the correct bottom relay view:
Customer: replied 8 years ago.

85 87 87a

86 30


OMRON 12172234 D00

I'm looking at the relay again. It is as I've laid it out above.

I tried to draw it out on Word but the image will not copy so you can see the drawing above.

Between 30 and 87a there is a diagonal connector line.

87 has three dashed lines and single connector coming down from pin 87

Between 85 and 86 there is a


| |

_|__ |

| | ______

| | | | < -- Diagonal line in this box from bottom left to upper right

|___| |_____|

| |

| |


I'm check the fuse/relay box under the hood. By location I have the correct relay pulled. It is also the only five pin relay in the fuse/relay box.

I wonder if there was an upgrade to the relay or someone (prior owner) put a different one into the fuel pump relay slot.

What you are talking about, is a diagram printed on the relay body.
My picture( was given above) represents the relay terminal location.
Look directly into the relay's terminals and then on my picture.
Does it make sense?
Customer: replied 8 years ago.
lol Yes it does.

Now we're on the same page.

Happy Thanksgiving!

So, I am waiting for your checking results.
Take note, that relay socket in the fuse/relay box has got a "mirror image" of terminal numeration.
Happy Thanksgiving!
Customer: replied 8 years ago.
Okay here's what I found out:

1. I drew out the diagram you sent, then held it up to a mirror...

2. Looking straight down on the socket for the relay the pin numbers come out like this according to the mirror 87 86 /|\ Front of vehicle
85 30

3. I found 12.35 volts on pin 87 (driver's side front female) with key on or key off.

4. I used the Fluke meter leads to jump from 87 to 30 and did not hear any clicking or noise. (key on or off).

5. Just to make sure I then used a piece of electrical wire and jumped 87 to 30. I hear a click and then the whine of the fuel pump. (Key off)
What about burnt sign on #30 or #87 female terminals?
1it is OK
2It is OK
3It is OK
4Your Fluke leads are not a jumper wire, unless you set up the Fluke for current (Amper)measurement .
5.It is Ok that the pump is running when you supply the power.
The question is, does the pump produce enough pressure? Only a fuel pressure gauge can tell.
I have forgotten to tell you about another problem place on these vehicles, it is a fuel pump module connector. One of two wires/pins( A grey +12, or a Black ground) might be burnt. Unfortunately, it is very hard to remove this connector without removing the fuel tank.
Vladgmru and 2 other Chevy Specialists are ready to help you
Customer: replied 8 years ago.
There are no signs of corrosion or being burnt on the female sides.

Looks like it's off to someone with more specialized tools. Smile

Thank you Vladimir. I have enjoyed this conversation and you teaching me

Be blessed, if there is a way to do so I'll let you know what is found out.

[email protected]
Thank you for the accept.
I am glad to be helpful and you are always welcome!
You can continue replying in this topic, but please do not post any private contact information ( such an E-mail ). We are not allowed to do so.
I am looking forward to hear from you.
Customer: replied 8 years ago.
Opps, sorry, I didn't realize that.

Thank you very much for the assistance.