weird idle

[95escahoe]

Hello I have a 95 Tahoe, picked it up last july when I got it it seemed to idle a lil weird at a stop the tach doesn't jump around or anything just doesn't seem that smooth at times, and when u start going its fine, so I replaced the plugs, wires, cap and rotor all with a/c delco parts and have them gapped the right ammount, and its still doing it....any idea as to what my problem might was thinking maybe the timing is off? or maybe egr or is there an igntion coil or anything that can go bad? thanks for the help

btw everynow and then my check engine light comes on but goes off maybe that has something to do with this too, most of the time when this happens there is no light on.....

 

[BattelWagun]

Well, I definitely would've inquired about that idle when you bought it. I'm doubting the timing could be off, do you know if it ever had any work done? (I.E. a new cam, timing chain, etc...) Also, the EGR isn't uncommon thing to go bad, but the light usually stays on when it fails, and theres always he possibility of a weak spark from the coil. If it is a weak spark you may be having a misfire, check your plugs, are any burnt up?

I've also heard of things like MAF's going bad etc. but I'm not too experienced in that area.

 

[95escahoe]

Well, I definitely would've inquired about that idle when you bought it. I'm doubting the timing could be off, do you know if it ever had any work done? (I.E. a new cam, timing chain, etc...) Also, the EGR isn't uncommon thing to go bad, but the light usually stays on when it fails, and theres always he possibility of a weak spark from the coil. If it is a weak spark you may be having a misfire, check your plugs, are any burnt up?

I've also heard of things like MAF's going bad etc. but I'm not too experienced in that area.

Engine wise pretty sure its all stock has no cam, gonna check the plugs, when I took the old ones off they were fine, thanks for the info

 

[oldsalt]

Sounds like an idle air control valve problem.

 

[AtomicHoe094]

Cenzo- no mass air flows on the 95 TBI trucks..

deff not the egr.. Figure out the code, put a jumper wire (paper clip) in and see what happens on the dash and come back.. sounds like a misfire tho

 

[retorq]

Check for vacuum leaks ... If it's not throwing a code then there is a good chance it's something mechanical, low fuel pressure, bad injector, vacuum leak, burnt wire, weak coil, etc.

 

[BattelWagun]

Cenzo- no mass air flows on the 95 TBI trucks..

Oh yeah... I forgot that 95 trucks were TBI...

In that case, check fuel pressure, vacuum, and spark strenth.