1996 Chevy Tahoe running rough at low RPMs

STEWWOP

MEMBER
1996 CHEVROLET TAHOE
V8
4WD
AUTOMATIC
50,000 MILES

My 96 tahoe runs rough(spits an sputters) between 1600 and 2100 rpms. Idles smooth when just sitting and runs like a champ anything above 2200 rpms. And it appears it gets worse as the truck runs longer/hotter. Recently replaced the fuel pump, just replaced the fuel filter, replaced the plugs and wires and cap 20,000mls ago. Just had a new transmission put in it and they replaced one of the O2 sensors. Could it be my fpr or my egr, or my iac valve, or another O2 sensor, something having to do with the throttle body? I don't have any codes pop up so I don't know where to begin. Don't want to start droppin a bunch of unnecessary parts into it.

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,755 POSTS

Without the light, it becomes a guessing game. My concern is that the light isn't coming on. If the engine is missing, it should. I realize that you replaced the fuel pump and filter, but is the pressure good at the fuel rail? Have you checked the regulator? Have you removed the EGR to see if it is full of carbon and sticking?

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Friday, December 11th, 2009 AT 10:08 PM

STEWWOP

MEMBER
4 POSTS

I just did. It did have quite a bit of build up on it that just might have been causing it to stick. I'm going to take it for a ride and see what happens.
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Sunday, December 27th, 2009 AT 5:04 PM

STEWWOP

MEMBER
4 POSTS

I just replaced the egr valve last night, at almost $200.00, and it still runs rough today. Spittin and sputterin at low throttle speeds. It ran well there for a couple weeks after I cleaned the egr valve, the throttle plate, and the mass air inflow, but there was also a really cold snap here in MN, it is now startin to warm up again and the problem is back. Maybe coincidence I don't know, but I fear it is going to cause other prob's if I don't get it figured out.
HELP!
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Saturday, January 16th, 2010 AT 4:26 PM