Rough idle and sluggish

twstice · #1 02-11-2005, 07:32 PM

I have a '95 grand prix gtp with the 3.4 DOHC. Whenever i come to a red light, or stop for a little bit, when i take off it kind of sputters untill i get above ~1200 rpms, then it is real smooth. But the odd thing is, when the engine is real warm like 180-190-200 degrees, i can come to a stop for a minute then take off and it's just as smooth as it can be. Also when my car is idling, i can just touch the gas peddle barely and completely take my foot off and it revs up to about 1100 and sticks there for about 10 seconds, then slowly eases down to 800-900 rpms (and sometimes sputters and/or fluctuates between around 550-800 rpms, it even just died one time.) Im guessing maybe the IAC valve and TPC maybe even EGR valve problems. Thanks ahead of time for Any suggestions.

twstice · #2 02-11-2005, 07:38 PM

sry, not TPC, i meant TPS (throttle position sensor) lol

BIG-L · #3 02-11-2005, 07:59 PM

Could be a problem with the MAF,try unpluging it when the car is cold and see if the problem goes away.

~Larry~

twstice · #4 02-11-2005, 09:44 PM

ahh, ok, i never thought of that, i will try it and let you know what happens

twstice · #5 02-11-2005, 10:11 PM

ok, i tried that, and the engine would idle at about 600 rpms barely runnin and when i'd tap on the gas it would still stay barely revved up over 1k for about 10 seconds and then idle back down

SUERED · #6 02-12-2005, 10:50 PM

Hello,

This just happened to my sister-in-laws '95 GP. Likely you have a clogged fuel injector. You need to go to a GM dealer parts counter and buy GM part #1050002 Top Engine Cleaner 15 oz can. This can states it is a carb/engine cleaner, but you can pour it into your gas tank. We had a half tank of gas when we installed this. Within 25 miles, problem solved and engine sounded as smooth as silk. It had sounded like it was running a cylinder short and was bucking. I was told that Seafoam also would work. I bet this is your problem.

John R

twstice · #7 02-13-2005, 12:16 AM

Ah, awesome, i will try that and let ya know how it goes.

twstice · #8 02-13-2005, 02:57 AM

I just noticed that on the rear right side of my intake, the little black vacuum box where two different vacuum hoses go in to it (not the one that is actually a sensor) but the one that bolts right in to the side of the intake right there, ....well the metal one looks like it is just sitting in the hole where it is supposed to be on with a rubber connector, LOL. would this cause some idle problems? j/w, cuz ima get that replaced asap. (anyone know what it is called so i can save some time of searching for the name?)

SUERED · #9 02-13-2005, 10:57 AM

Oh, That cleaner is about $7.00 a can. It is ackward to pour into the tank but I am sure you can manage. By the way--what's the mileage on the GP? The other issue is the condition of your fuel filter. If you have over 50,000 miles and it was never changed---that might be part of it too.

John R

twstice · #10 02-13-2005, 07:09 PM

the mileage is almost 119,000. and the fuel filter is new, i recently changed it in hopes of that helping too, lol. But im not sure really where i can get that cleaner. I live in Corinth, MS, and not really sure where around here i could get that, unless O'Reilly, Autozone, Advanced, or NAPA would sell that?

twstice · #11 02-13-2005, 07:11 PM

Actually, i think Brose and Copeland automotives here are GM dealers, i will check there.

twstice · #12 02-13-2005, 07:28 PM

Oh, this is off the subject, but i just thought of this....i cant figure out what the bolt is called, but i will try my best to describe it. OK, imagine lookin under the car, and the rubber boots (like 4-6?) that hold basically the whole front end on the unibody. ....well whatever bolt that is, i am missing one on my driver side. I talked to autozone and they said it would more than likely have to be a dealer item, so if anyone could let me know what that bolt is called i could ask the GM dealer about buyin one. Thanks.

jon95se · #13 02-13-2005, 08:29 PM

are you taling about the subframe mount? if your missing that. get it replaced soon.

one other thing i would check is your idle air controller.

twstice · #14 02-13-2005, 10:24 PM

yea, that sounds like the right bolt. i will ask about that too. and i will check the idle air control valve as well.

twstice · #15 02-14-2005, 08:37 PM

Ok, i just got the Top Engine Cleaner today, and i bought a set of spark plugs, and as soon as i get oil and filter i will do all of this and let you all know how it goes. I read at another place that the spark plugs could foul and a fresh oil change would be needed after running this through the engine, but i dont know where to put it, lol, gas tank? oil filler? ? anyway, i will be searching, if anyone knows plz post it, maybe itll save me some long searching. Thanks ahead of time ( This is for the 3.4L engine, remember, not sure if that makes a difference, but doesnt hurt just to be sure, lol)

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