Failing fuel pump

1,845

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

27,535

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

1,845

The injection spider was replaced back in july of 2015

1,845

nice steady cruzz

27,535

first things first.. is the filter new??

74,765

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 of 1 people found this helpful.
19,545

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 of 1 people found this helpful.
1,845

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.

74,765

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

19,545

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.

1,845

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

S-10

Looking for a Used S-10 in your area?

CarGurus has 1,251 nationwide S-10 listings starting at $1,600.

ZIP:

Chevrolet S-10 Experts

  • #1
    Andrew Olsen
    Reputation
    2,460
  • #2
    John Saffrahn
    Reputation
    1,040
  • #3
    Trebor66
    Reputation
    1,030
View All

Related Models For Sale

Used Ford Ranger
145 Great Deals out of 5,392 listings starting at $800
Used Chevrolet Silverado 1500
2,245 Great Deals out of 168,632 listings starting at $1,000
Used GMC Sonoma
5 Great Deals out of 414 listings starting at $2,200
Used Toyota Tacoma
563 Great Deals out of 44,573 listings starting at $1,790
Used Ford F-150
2,561 Great Deals out of 198,634 listings starting at $1,500
Used Dodge Dakota
86 Great Deals out of 3,682 listings starting at $1,999
Used Nissan Frontier
327 Great Deals out of 23,237 listings starting at $2,495
Used Chevrolet Blazer
3 Great Deals out of 1,076 listings starting at $950
Used GMC Sierra 1500
1,003 Great Deals out of 65,787 listings starting at $1,975
Used Dodge Ram 1500
357 Great Deals out of 10,827 listings starting at $1,500
Used Chevrolet Camaro
431 Great Deals out of 30,654 listings starting at $1,450
Used Chevrolet C/K 1500
884 listings starting at $1,900
Used Chevrolet Tahoe
714 Great Deals out of 41,440 listings starting at $1,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.