Failing fuel pump

1,535

Asked by Jan 06, 2016 at 07:39 PM about the 2000 Chevrolet S-10 2 Dr STD Standard Cab LB

Question type: Maintenance & Repair

2000 S-10 V 6  with 255,432 miles. Check engine light on with code PO 300
(random misfire) and PO 171 (system too lean)
Replaced fuel filter ,checked for vacum leak with gage (needle steady at idle)
changed MAF sensor . While driving at about 70-74 mph tach at about 2100
rpm the engine will stumble and the tach will show a slight drop in rpm's. Not
continuously.The fuel pump was replaced in 2007 that was 113,000 miles
ago.Could the out put from the fuel pump be decreasing causing this type of
problem?

10 Answers

19,235

sure..but under a load or a nice steady cruze??? also check...wiggle any/all elect conections you can find.

1,535

The injection spider was replaced back in july of 2015

1,535

nice steady cruzz

19,235

first things first.. is the filter new??

37,985

I'd check the fuel pressure at the schrader valve, it should be 56 to 63 lbs. just to be sure. The common thing for the random miss-fire, and a lean condition is a intake manifold leak. Try taking some carburetor cleaner and spray along the intake gaskets, plenum , base of throttle body, If the rmp's increase, then there is a vacuum leak.

1 out of 1 people think this is helpful.
16,255

Make sure there is no air entering the tubing after the maf sensor. All clamps are tight, the pcv hose is in good shape. No cracks anywhere and the plenum is seated good and tight on the top of the throttle body.

1 out of 1 people think this is helpful.
1,535

I did notice that the "O"ring that seals the top of the throttle body was flat from age.Think I should start with a new "O" ring. That would produce a lean mixture.

37,985

Anywhere there is vacuum. Spraying carb cleaner would have picked this up. Increase in RPM's...

16,255

Yes, it will cause a lean code if air enters there because of that o ring. The problem with the carb cleaner test is there isn't vacuum there. It doesn't always work for the plenum before the throttle body.

1,535

Update: Used starting fluid and sprayed areas of possible vacuum leaks. No leaks where found. Sprayed area around base of intake and throttle body. Still no increase in RPM's. Did notice that the "feeling" of the engine stutter is at 2000 rpm's. Highway speed of about 70 -74 mph. Could my throttle position sensor have a bad spot at that point?

Your Answer

Add photo

Related Questions

  • Fuel pump 1 answer

    I have a 96 Chevy s10 6cyc. Vortec engine Well when the temp goes up meaning the weather the fuel pump makes a loud buzzing sound and the truck dies. My temp gauge is normal ,I don't understand it...

    1996 Chevrolet S-10 2 Dr LS Extended Cab SB

    -

    Maintenance & Repair

  • Can the ignition control module on a 1997 Chevy S-10 be tested on a testor , be passed as OK and still be failing when installed on the engine? 2 answers

    Truck would start, but would not run when throttle was opened. Replaced fuel pump, Pressure regulator,and filter. It started right up, responded to throttle just fine, and I took it out for a test ...

    1997 Chevrolet S-10 2 Dr LS 4WD Extended Cab SB

    -

    Maintenance & Repair

  • Fuel pump interchange 2 answers

    Fuel pump interchange

    1996 Chevrolet S-10 2 Dr STD 4WD Standard Cab LB

    -

    Maintenance & Repair

  • replacing fuel pump 2 answers

    replacing fuel pump in a 97 S10 pickup and with this said new fuel pump came a new wiring harness. i would like to know how to attach these together.

    1997 Chevrolet S-10 2 Dr LS Extended Cab SB

    -

    Maintenance & Repair

  • is my fuel pump failing? 5 answers

    periodically my 2005 optra 4 door LS will give me trouble starting. i know its a fuel problem through various trial and error. when i tried to start it the other day, it wouldnt. i had my girl friend ...

    2005 Chevrolet Optra

    -

    Maintenance & Repair

S-10

Looking for a Used S-10 in your area?

CarGurus has 1,646 nationwide S-10 listings starting at $995.

ZIP:

Search Chevrolet S-10 Questions

Chevrolet S-10 Experts

#1 Andrew Olsen
Andrew Olsen
Reputation 2,060
#2 John Saffrahn
John Saffrahn
Reputation 890
#3 Trebor66
Trebor66
Reputation 880
View All

Related Models For Sale

Used Ford Ranger
223 Great Deals out of 7,061 listings starting at $1,450
Used Chevrolet Silverado 1500
2,763 Great Deals out of 150,217 listings starting at $1,259
Used GMC Sonoma
9 Great Deals out of 510 listings starting at $1,500
Used Toyota Tacoma
801 Great Deals out of 34,292 listings starting at $2,988
Used Ford F-150
3,487 Great Deals out of 207,667 listings starting at $1,273
Used Dodge Dakota
156 Great Deals out of 4,409 listings starting at $1,500
Used Chevrolet Blazer
4 Great Deals out of 1,394 listings starting at $1,399
Used Nissan Frontier
460 Great Deals out of 22,239 listings starting at $2,350
Used GMC Sierra 1500
1,197 Great Deals out of 58,876 listings starting at $2,495
Used Dodge Ram 1500
547 Great Deals out of 13,072 listings starting at $1,800
Used Chevrolet C/K 1500
3 Great Deals out of 1,057 listings starting at $1,999
Used Chevrolet Camaro
630 Great Deals out of 39,689 listings starting at $2,995
Used Chevrolet Tahoe
1,082 Great Deals out of 32,101 listings starting at $1,495

Used Cars For Sale