Question about 2000 GMC Jimmy

1 Answer

Bucking at speeds over 60 or after it has rained

The garage wants to replace the air pump and i think it has somthing to do with the tune up I just did. Maybe the bosch spark plugs could be the problem. Not only does it buck after a few bucks at 65 it will downshift into a passing gear and wont shift back up until i slow to 50 or 55 for a few minutes. What should i do ?

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 702 Answers

If you can find a place will be scan your system for you that would be good. Where ever you take it, have them look at the O2 sensors switching. You may have an O2 sensor being really lazy or not working at all. I don't think your air pump has anything to do with your problem. You may be experiencing a torque convertor lock up problem as well. Definitely get a data stream done before changing any parts that you don't need replaced.

Posted on Nov 01, 2008

  • Lee Quiroz
    Lee Quiroz Nov 01, 2008

    One thing I failed to see, check the distributor cap for moisture in it especially after it rains. I didn't see the "after it has rained" comment. the convertor most likely has nothing to do with what is happening. I don't thing your O2 sensors have anything to do with it either now. Double check the timing on your truck instead.



1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

When accelerating from 60-70, it is jerking o r bucking

all cars do that, called misfire , all do it never tuned up.!
what mileage on that engine, from last tuneup.? and total miles
100k,? what?
if that is engine buck and not transmissions slip or unexpected shifts.
then that is called MISFIRE<
and #1 cause, is bad spark plugs.(warn out as ALL DO)
there are 49 more causes, but most times not on newer cars.

ever get that car serviced, ?
all cars buck ignored, all. for 100 year in a row. (gas)
if the spark is good.
we use a scan tool and watch for DTCs during the buck.
the Scan tool will tell you , if the ASD relay drops causing said buck and why.
there is no other ways... to fix, not bad spark plug bucking
takes tools.

I have 2010, same engine, in my priv garage. (Grand Cher)
and its got fresh spark plugs in it.
the are not easy to change out. ask.
has COPs in the way. and more...

use the best spark plugs you can find, to make them last longer and not have to pull those cops too often.
also the cops have boots that can carbon foul.
but the service shop knows all this stuff. let them>?

Nov 23, 2015 | 2012 Jeep Liberty Sport 4dr SUV 3.7L V6...

2 Answers

1994 crown victoria engine races

Problem with idle speed. The idle is controlled by the pcm (engine computer) through the operation of the Idle Air Control valve or motor. But several other sensors are also at work, like the throttle position sensor, the coolant temperature sensor, the MAP sensor or the Mass Air Flow sensor. The computer monitors all engine conditions to optimize performance and driveability-this includes keeping idle speed correct.
Would probably help you if you could see what all those sensors are telling the pcm-so you need a scanner capable of giving live stream data. And don't forget, your '94 is OBD-1, not OBD-II like all cars since 1996 on have. A garage should have such capable scanners, but they are kind of high end, not your typical cheap code scanner.

May 07, 2017 | 1994 Ford Crown Victoria

3 Answers

Cranks over but wont start

fuel pump went out just like mines

Feb 01, 2013 | 2002 Pontiac Montana

1 Answer

My 1996 sentra is bucking and kicking while driving and dies when idling at lights. I have replaced air, fuel filters as well as wire and plugs. Check engine light does not come on. Fuel economy goes from...

idle control valve will need cleaning, also the mass air flow as well ( mas air flow cleaner only recommended) and the air temp sensor. may need cleaning or replacing, it could also be the spark plugs or leads. it could also need the egr cleaning as well, and sometimes it can be from were you get your fuel. if the garage you get your fuel from when its rain and you fill up and then have problems there could be water in the fuel as some garages don't know that ground water is getting into the tanks under ground.

Aug 04, 2017 | 1996 Nissan Sentra

1 Answer

Car bucking at speeds above 60 mph

could be sensor has failed or could be in need of tuneup...

Aug 16, 2012 | 2000 Volkswagen Beetle

1 Answer


12 yrs for a injector too old. really need to replace. the nozzle gives unacceptable spray pattern. that's why not get the proper performance of the engine.

Dec 30, 2010 | 1983 Volkswagen Rabbit Pickup

1 Answer

Vehicle sputters or shake at cruise speed.

Jealousy ?

Seriously though, I would plug it into a garage diagnostics machine before replacing parts.

Just ask for a tune / emissions test & say there is a fault at cruise.
They should be able to see a faulty sensor or odd readings to pinpoint the cause, and will be cheaper than a new coilpack.

Sep 22, 2009 | 1997 Ford Expedition

1 Answer

1989 Plymouth Horizon

replace the egr valve and the PCV valve possible a new air filter also

Mar 09, 2017 | 1989 Plymouth Horizon America

Not finding what you are looking for?
2000 GMC Jimmy Logo

Related Topics:

85 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts


Level 3 Expert

77499 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22306 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6927 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides