2001 GMC Jimmy 4.3L rough idle lean condition

130

Asked by Dec 05, 2013 at 10:32 PM about the 2001 GMC Jimmy 2 Dr SLS SUV

Question type: Maintenance & Repair

I have an 2001 gmc jimmy 4.3 l while driving home it started running rough and stalled out but would start back up but idles rough and when I put in gear it runs worse and stalls I found there was a fuel leak in the upper manifold and the fuel pressure was 53 psi. with a bad misfire on 1 and 2 cylinder I replaced the spider and the pressure regulator. it still idles  rough and the long fuel trims show 25%  so its requesting more fuel a lean condition but goes to normal when you bring the RPMs to 1000 and up I have looked for vacuum leaks and can't find any. fuel pressure is now up to 55 psi. could the pump cause this or what do you think this is.

8 Answers

130

I had replaced the spark plugs and wires no change in the way it runs. I also tried the unplugging the MAF and there was no change. I did find a leak in the exhaust just past the O2 sensor so I will be fixing that next. if any one has any thing to add I'm open to other fixes

5 of 5 people found this helpful.

is there not a fuel pressure regulator...accessing, accessing...

3 of 3 people found this helpful.
130

the new spider I bought came with a new fuel pressure regulator on it already

2 of 2 people found this helpful.
130

I put in the new fuel pump and the pressures are right and it acts as it should now when you snap the throttle but it still is missing and running rough at idle its showing a lean condition at idle but then my starter went out so I need to fix that to continue the diagnosis any other help my ears are open

3 of 3 people found this helpful.
19,505

roy, the spider assembly has a regulator on it. make sure the intake plenum (tubing between maf and throttle body) is in good shape. Any air entering here will cause a lean condition. Your fuel pressure is spot on. Also take your brake booster line off and plug it. I've had a leaky booster before.

2 of 2 people found this helpful.
130

just an update the distributer cap was cross firing on the in side on 1 and 2 cylinders causing the miss fire but with the spark test you would still have spark just not firing at the right time causing a miss fire on those two cylinders. causing a lean condition. replaced that and it runs good now

3 of 3 people found this helpful.

as long as I'm a guessin' fool...am going to suggest an intake air temperature sensor may be playin' hell with the mix~ http://www.autopartswarehouse.com/sku/GMC/Jimmy/Standard/IAT_Sens or/2001/SIAX32.html? apwcid=productads&003=27846857&010=apwSIAX322001gmjiiase&gcl id=CNOckZ2F4LsCFa9cMgodpXEA2Q

2 of 2 people found this helpful.

another zinger is the Idle air control~ https://www.google.com/#q=2001+GMC+Jimmy+4.3L+idle+air+control&tbm =shop

4 of 4 people found this helpful.

Your Answer

Jimmy

Looking for a Used Jimmy in your area?

CarGurus has 319 nationwide Jimmy listings starting at $2,500.

ZIP:

GMC Jimmy Experts

  • #1
    Andrew Olsen
    Reputation
    310
  • #2
    1oldman
    Reputation
    270
  • #2
    tennisshoes
    Reputation
    270
View All

Related Models For Sale

Used Chevrolet Blazer
4 Great Deals out of 1,075 listings starting at $950
Used GMC Yukon
428 Great Deals out of 22,353 listings starting at $1,995
Used GMC Sierra 1500
986 Great Deals out of 66,547 listings starting at $2,495
Used Chevrolet Tahoe
696 Great Deals out of 41,238 listings starting at $1,995
Used GMC Envoy
50 Great Deals out of 2,146 listings starting at $1,482
Used Ford F-150
2,479 Great Deals out of 193,508 listings starting at $799
Used Ford Explorer
877 Great Deals out of 67,246 listings starting at $1,295
Used Chevrolet S-10
15 Great Deals out of 1,260 listings starting at $1,600
Used Chevrolet TrailBlazer
93 Great Deals out of 4,576 listings starting at $1,300
Used Toyota Tacoma
568 Great Deals out of 43,788 listings starting at $2,200
Used GMC Sonoma
3 Great Deals out of 473 listings starting at $1,000
Used Oldsmobile Bravada
212 listings starting at $3,700
Used Ford F-250 Super Duty
312 Great Deals out of 45,034 listings starting at $1,700

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.