Hello I Have a 89 GMC 2500 and it hesitates when you start moving but once you get past the intial start it runs fine. You can hear it miss when its idling also. Anyone know what causes this?

Asked by JasonNID Mar 10, 2014 at 07:20 PM about the GMC Sierra 2500

Question type: Maintenance & Repair

The following has been replaced: Spark plugs and wires, Distributor cap and rotor, oil pressure gauge switch, fuel filter, and  inspected ignition cables

3 Answers

31,245

? Spark or fuel. Is it flooding or leaning out. If it's lean Check the injector spray pattern. If it looks weak check the fuel pressure, I think they are 10 to 13 psi. If the fuel is good check your plugs and the spark at each plug. It may be the pick-up coil or weak ICM. If it's rich (flooding out) the pressure may be too high, NFG regulator in your throttle body???

The Injectors sputter spray when you first apply the gas then it sprays as it should. The spark plugs are clean. I will check the coil and ICM and NFG and see if that's the problem.

31,245

LOL, NFG = No F$%#in Good. Check the spark at the plugs -> pull them out one at a time and ground them to the motor and start the truck. Should see a bright blue spark. If the injectors are spraying incorrectly when the sputtering happens that's were I would look. Once you get it moving it's good but what about if you give it lots of gas, like if you were going to pass someone. That would indicate low fuel flow, plugged fuel filter, partial failure of the fuel regulator or weak pump. Check the first two first as the in tank fuel pump is a dirty job.

1 people found this helpful.

Your Answer:

Sierra 2500

Looking for a Used Sierra 2500 in your area?

CarGurus has 2 nationwide Sierra 2500 listings and the tools to find you a great deal.

Postal Code:

CarGurus Experts

  • #1
    Rowefast
    Reputation
    180
  • #2
    Gene Arnett
    Reputation
    170
  • #3
    mikeatpriestlake
    Reputation
    70
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used GMC Sierra 2500HD
17 Great Deals out of 1,640 listings starting at $9,988
Used Chevrolet Silverado 2500HD
16 Great Deals out of 1,285 listings starting at $8,995
Used GMC Sierra 1500
148 Great Deals out of 7,258 listings starting at $3,950
Used Ford F-250 Super Duty
24 Great Deals out of 1,204 listings starting at $7,995
Used Chevrolet Silverado 1500
202 Great Deals out of 5,975 listings starting at $2,975
Used RAM 2500
55 Great Deals out of 2,180 listings starting at $14,962
Used GMC Sierra 3500HD
17 Great Deals out of 1,384 listings starting at $11,950
Used Ford F-150
321 Great Deals out of 14,968 listings starting at $1,712
Used Chevrolet Silverado 2500
2 listings starting at $12,500
Used Dodge RAM 2500
23 listings starting at $9,975
Used Ford F-250
6 listings
Used GMC Yukon
16 Great Deals out of 929 listings starting at $1,225
Used RAM 1500
439 Great Deals out of 15,809 listings starting at $5,000
Used Chevrolet Silverado 3500HD
11 Great Deals out of 881 listings starting at $21,999
Used Chevrolet Silverado 3500
4 listings starting at $29,975

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. Content will be removed if CarGurus becomes aware that it violates our policies.