Question about 2000 GMC Jimmy

2 Answers

Hi I have a 2000 gmc jimmy with a rough idle here is the story I bought this truck with a blown intake gasket and a misfire. I replaced the intake gasket during disassembly I noticed that the #4 spark plug wire had been rubbing on the ground strap and looked like it had been arcing so I did a complete tune up plugs,wires,cap,rotor. I got it all back together started it up and noticed it has a rough idle but if you give it gas it clears up and runs grate it is setting code P0303 so I swapped plugs no change swapped wires no change. I know these engines have problems with the poppet nozzles getting clogged so I replaced the injector unit with the upgrade MFI unit but did not fix. When I was replacing the injector unit I noticed alot of carbon so I checked the EGR valve it was not stuck open and the pentle moved up and down without sticking. I also looked at the MAF sensor it did not look dirty also checked PCV valve it looked like it had been replaced I shook it and it did not stick. I checked fuel pressure key on engine off 60 psi with the engine running it has about 55 psi that may be a little low but would that cause a misfire on cyc 3 only? I don't think so but I guess any thing is possible. thanks for reading if any one has any thoughts I am open to suggestions.

Posted by on

Ad

2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • GMC Master
  • 1,150 Answers

Suggestion.....I had same problem with my 2000 Jimmy. For your info, aftermarket distributor caps for this engine have a design flaw that causes internal arcing. Buy an AC Delco brand cap. I chased this problem for a month, went through several brands of aftermarket caps, prior to finding this info out.

Posted on Mar 03, 2017

Ad
  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • GMC Master
  • 12,467 Answers

55 psi that may be a little low but would that cause a misfire on cyc 3 only? NO that would affect all cylinders not just one . Do a compression test on # 3 cylinder .

Posted on Mar 02, 2017

Ad

2 Suggested Answers

6ya6ya
  • 2 Answers

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

Hi,
a 6ya expert 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 repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

  • 14585 Answers

SOURCE: 1999 GMC Jimmy 4.3 gets P0303 (#3 misfire) Changed

Yes . You need an ohm/ volt meter. First check the injector, at the leads of the injector you should have 11 to 15 ohms. At the injector plug with the ignition on you should have 12 volts at one of the wires. To check for fire at the plug put the meter leads on the plug leads and crank the engine. the voltage should spike. My guess is that you have a bad wire on the #3 injector. All the injectors will have 12 volts with key on. The ECM grounds the injectors according to where the crank/cam sensor is. On your vehicle it fires 2 cylinders at a time. This is why I say you have a bad /broken wire. At the #3 injector plug you can also check for ground to the ECM. Instead of putting both leads to the plug you have to first find the ECM wire, then put the meter leads to that wire and ground on the battery. Again it should spike in ohms

Posted on Sep 05, 2011

Testimonial: "I didn't solve my problem yet but his advise was very helpful!"

Add Your Answer

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

1 Answer

What causes my 2000 GMC jimmy envoy 4.3liter vortex to misfire when fueling?


misfire when fueling ???? You leave the vehicle running while fueling ?

Apr 05, 2017 | 2000 GMC Jimmy

1 Answer

Will intake gasket leak make the lifters tic when first starting


I dont think and intake gasket will cause lifter noise. It may cause a rough idle and or a miss at idle on cold start up . as the engine warms up the miss or rough idle will decrease . As for the lifter noise this could be cause by the lifter bleeding down or poor oil presure . On your model of engine there is no adjustment on the rocker arms for lifter noise . They are a 0 lash type .

Mar 06, 2011 | 2001 GMC Jimmy

2 Answers

98 gmc jimm 4x4 4.3l v6 replaced plugs, wires and distributor cap and rotor. Still getting P0304 code and rough idle. Higher rpms flatten out roughness but take off feels off. Any help??


spray carb/choke cleaner all around intake gasket mating surface on heads. (while motor is running) If rpms change you have a bad intake gasket.

Feb 07, 2011 | 1998 GMC Jimmy

1 Answer

Recently I had my 2000 gmc 2500 6.0 liter truck start running rough. I changed the spark plugs, checked the coil packs and replaced the fuel pumpand fuel filter. Still no change....Any suggestions?


ROUGH IDLING CAN BE CAUSE BY MANY THINGS.I AM LOOKING AT LEAKING VACUUM HOSES OR INTAKE MANIFOLD GASKET LEAK.DIRTY FUEL INJECTORS AND WORN ENGINE VALVES WILL CAUSE ROUGH IDLING.ALSO LOW IDLE SPEED CAUSE ENGINE TO RUN ROUGH.

Apr 18, 2010 | 2000 GMC New Sierra 1500

1 Answer

95 gmc jimmy rough idle fuel in exhaust drives


Purchase new egr valve gasket with screen on it. The motor as it get older produces more carbon it then begins to break off and when the valve opens it get caught in there. i have cleaned mine several times and finally found the gasket at napa for around 22 bucks. All you need it 10mm wrech and 10mm socket with ext. takes around 10 min to do.

Jan 10, 2010 | 1993 GMC Jimmy

3 Answers

2001 GMC Jimmy Idling rough


HI
P0300 is multiple misfires.
P0171 is lean burn on left bank 1 means drivers side
02 sensor is faulty. Your vehicle is over fuelling that is why your are getting P0300 code and the rotten egg smell. Good idea is to replace both 02 sensors.

Apr 04, 2009 | 2001 GMC Jimmy

1 Answer

Severeal cylinders misfire


Sounds like the TPS (throttle position sensor) usually located where the throttle body meets the intake manifold. It may need re-calibrating or renewing.

Feb 06, 2009 | 1991 GMC S-15 Jimmy

2 Answers

I blew a manifold gasket & my 2000 gmc jimmy 4x4,4.3 and it severly overheated.Now it has a rough idle after being fixed.A code scanner is showing a DTC 300,Random Multiple Misfire.


Its common for spark plugs to get severely fouled after intake manifold leaks due to coolant entering cylinders. Sounds like you had experienced this because you stated a severely overheated engine. This is the first place to start... there could be other issues but this is the order to go in.then p.c.v valve, wires and mass airflow sensor. Hope this helps.

Aug 24, 2008 | 2000 GMC Safari

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

Related Topics:

201 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts

yadayada
yadayada

Level 3 Expert

76846 Answers

Freddy

Level 3 Expert

1311 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22246 Answers

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

Answer questions

Manuals & User Guides

Loading...