93 gran prix bucking dying

Justin101 · 07-25-2006, 06:58 PM

i have had it a year and dont want it but we need it!! What it is doing is bucking, ill come to a stop light and it will buck form 1,000 to 2000 rpm till i come to a stop. then i come to a stop and it will dye, ill put it in nuetral and still does it. so my wife just drives gas brake but it's getting old. we replaced the throttle position sensor, map sensor,air intake sensor. still doing it although we replaced the tps and it stopped for, um a month, so i figured another sensor , ( so i thought i was getting a good man made american part) so i bought a code reader! $$$$$$$$$$ it is saying throttle position sensor, so i tested the voltage all good going to it, everybody tells me that you can get crappy throttle position sensors. this sensor is in a bad spot to change its on the 3.1 if anybody knows where it is at. i have yet to clean the throttle body it is black and carboned up but i dont want to do it i want to know if you can get a bad throttle position sensor!! and is there a better way to change that beside hire skinny guys with little fingers no offense! and has anybody had this kind of problem also it is whinning in 2nd and 3rd gear fluid is fine though !

Justin101 · 07-25-2006, 07:14 PM

Someone please reply to this please!!

maxwedge · 07-25-2006, 08:32 PM

Quote:

Originally Posted by Justin101

i have had it a year and dont want it but we need it!! What it is doing is bucking, ill come to a stop light and it will buck form 1,000 to 2000 rpm till i come to a stop. then i come to a stop and it will dye, ill put it in nuetral and still does it. so my wife just drives gas brake but it's getting old. we replaced the throttle position sensor, map sensor,air intake sensor. still doing it although we replaced the tps and it stopped for, um a month, so i figured another sensor , ( so i thought i was getting a good man made american part) so i bought a code reader! $$$$$$$$$$ it is saying throttle position sensor, so i tested the voltage all good going to it, everybody tells me that you can get crappy throttle position sensors. this sensor is in a bad spot to change its on the 3.1 if anybody knows where it is at. i have yet to clean the throttle body it is black and carboned up but i dont want to do it i want to know if you can get a bad throttle position sensor!! and is there a better way to change that beside hire skinny guys with little fingers no offense! and has anybody had this kind of problem also it is whinning in 2nd and 3rd gear fluid is fine though !

Um sounds like you are fighting yourself here, what is the reason for not cleaning the TB. Have you had a full function scanner on it and read the tps inputs at idle, clean the idle air control? Backprobe terminals c and b with a high impedance dvom throttle closed it should be .5-1.2 v, open the throttle slowly the voltage should move smoothly to 4.5v. This is all basic diagnostics for this condition. A sticking egr can cause an idle stall also. If you are not comfortable doing these procedures take it to a pro. BTW, I would condsider it unreasonable to expect an answer here in 15 minutes!

richtazz · 07-26-2006, 07:00 AM

If the TB is carboned up, it could be a sticking IAC valve also, there is no point to changing out parts when a known problem exists. Like Max said, quit fighting yourself and clean the TB, EGR passage and IAC bore first.

Justin101 · 08-09-2006, 07:39 PM

Hey guys i thank you for your info um i started doing all this, i cleaned the throttle body, it was carboned up, so i cleaned it then i felt that the egr passage was clogged so i cleaned it, then cleaned out the egr, put it all back together and reset the ecm, it scans fine now but the bucking and flat spot is still there, oh i also replaced the tps just to do it while it was out and easy to get to. i bought a digital multimeter and it is broke so i got to take it back and get another one, other than that i havent got anything else to say but if you do please repond, ido know that you must drive 40-50 miles for the brain to record new info so im gonna go do that ! thanks oh i also cleaned the iac bore to and sprayed it the metal parts of it and tried to clean it up to.

Justin101 · 08-10-2006, 08:55 PM

Ok i read it after forty miles and know it is saying that its the mass air flow or the manifold absolute pressure sensor, then it say note: engine misfire or unstable idle may cause this code. it doesnt misss or hesitate at all though. guys im clueless as to whats going on here. so im gonna have to break down and go get it in to a big wig if you guys have anything to say please comment, it will help even the slightes info.thanks

richtazz · 08-11-2006, 06:57 AM

check the vacuum line to the MAP sensor for cracks. The codes you are getting all point to a vacuum leak somewhere.

Justin101 · 08-29-2006, 03:01 PM

well I found out what it was! oh the humanity, it was the EGR , yep thats what it was, runs and drives like a dream all for 290.00 thats all.i went and had it tested and one of the things inside was stuck open so i went and bought a new one, and got bored and tore the old one apart and got it unstuck , pretty carboned up, but know it works to so i have the old one as back up, but just wanted to say thanks top everyone who had helped me!

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