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 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

10,395

? 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.

10,395

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 of 1 people found this helpful.

Your Answer

Add photo

Related Questions

Sierra 2500

Looking for a Used Sierra 2500 in your area?

CarGurus has 164 nationwide Sierra 2500 listings starting at $3,195.

ZIP:

Search GMC Sierra 2500 Questions

GMC Sierra 2500 Experts

#1 Rowefast
Rowefast
Reputation 160
#2 tennisshoes
tennisshoes
Reputation 90
#3 JOHNG123
JOHNG123
Reputation 60
View All

Related Models For Sale

Used GMC Sierra 2500HD
125 Great Deals out of 12,841 listings starting at $2,995
Used GMC Sierra 1500
788 Great Deals out of 68,701 listings starting at $1,800
Used Chevrolet Silverado 2500
13 Great Deals out of 246 listings starting at $3,900
Used Chevrolet Silverado 2500HD
298 Great Deals out of 28,514 listings starting at $1,500
Used Chevrolet Silverado 1500
1,914 Great Deals out of 183,082 listings starting at $1,495
Used Dodge Ram 2500
125 Great Deals out of 5,076 listings starting at $2,999
Used Ford F-250 Super Duty
324 Great Deals out of 44,694 listings starting at $1,450
Used Ford F-150
2,167 Great Deals out of 195,111 listings starting at $290
Used Ford F-250
462 listings starting at $4,690
Used GMC Sierra 1500HD
3 Great Deals out of 117 listings starting at $4,995
Used GMC Sierra 3500
4 Great Deals out of 230 listings starting at $8,999
Used Toyota Tundra
458 Great Deals out of 34,712 listings starting at $2,500
Used Dodge Ram 1500
420 Great Deals out of 10,945 listings starting at $1,000
Used Chevrolet C/K 2500
199 listings starting at $6,499
Used Ram 2500
129 Great Deals out of 29,083 listings starting at $7,490

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.