1999 GMC Sierra Fuel Pump/relay

ADSMTZ

MEMBER
1999 GMC SIERRA
V8
4WD
AUTOMATIC
206,800 MILES

I have read a lot of fuel pump questions. My problem for about 8 months.

I turn the key on, motor turns over fine.
I have to turn the key off and start it again. (Kind of like the old diesel motors with glo plugs). I hear a clicking and the fuel rail pressuarize and it fires right up. I have changed every relay under the hood, side panel and by the brake pedal.

changed the spark plugs (new style)
changed fuel pressure regulator
Checked Map sensor and O2 sensor

No codes, It runs great when it starts. Been like that for a while.

Should I check with fuel pressure gauge.

4 Replies

RASMATAZ

MECHANIC
75,992 POSTS

When the fuel pressure checks out test the ignition switch

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Monday, June 21st, 2010 AT 6:04 PM

ADSMTZ

MEMBER
3 POSTS

The first time it was only 25 psi.
Cycle the key it got up to 34 or so.
Third time I cycled up to 55 psi
Everytime after that it was 60 plus.

It seems to drain or lose prime after it sits for 10 minutes or so. I have to cycle through the keys to get the pressure up.

After it starts, it does not hessitate or give me any problems on the road.

New Fuel Filter and Fuel Pressure regulator relaced as well as all new relays.

Is this my fuel pump?