1995 GMC Jimmy bad idle

GMC GUY

MEMBER
1995 GMC JIMMY
6 CYL
4WD
AUTOMATIC
313,000 MILES

I have a 95 Jimmy the wont idle, But when I give it gas it seems to run good, when I go to brake it seems like the brake booster is not working and the truck want to stall. Could it be the sending unit in the gas tank not working properly. Or could be something totally different.

2 Replies

SWILLIAMS

MECHANIC
597 POSTS

Could be a large vacuum leak causing both problems. Check the EGR function and check the brake booster as well.

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Friday, November 14th, 2008 AT 9:39 PM

ASEMASTER6371

MECHANIC
52,797 POSTS

Good afternoon.

This was a common problem back in the day.

The EGR valve gets stuck open from carbon not allowing the valve to close. This causes a massive vacuum leak and there is not enough vacuum to the booster and you get a rough idle.

Remove the EGR and check for any carbon.

Roy

NOTE: Do not try to disassemble the linear Exhaust Gas Recirculation (EGR) valve. It is serviced only as a complete assembly.

REMOVE OR DISCONNECT
1. Electrical connector.
2. Valve to flange attaching bolts.
3. Linear EGR valve.
4. Flange gasket.

CAUTION: The linear EGR valve is an electrical component. Do not soak it in any liquid cleaner or solvent, as damage may result.

Clean:
Linear valve gasket surface.

INSTALL OR CONNECT
1. Flange gasket.
2. Linear EGR valve.
3. Valve to flange attaching bolts.

Tighten
Valve to flange attaching bolts to 24 Nm (17 lb. Ft.).

4. Electrical connector.

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