Rough Idle Nightmare
Thread Starter
Intermediate
Joined: Oct 2002
Posts: 29
Likes: 0
From: St. Louis Mo.
Rough Idle Nightmare
Help........
My 89 coupe has a rough idle. I've replaced air filter, fuel filter, Disb. Cap & Rotor, Ign. Coil, Pvc Valve, IAC Valve, readjusted idle per manual and this site, checked tps (.54volts) and still roughhhh.
I'm going crazy....I bought a EGR & EGR solinoid which I plan to install this weekend. I'm also thinking MAF(how do I test the MAF?) and maybe the ECM. I've also read in several posts that several people have their TPS set at .64volts. The manual says to set it between .54 and .75 should I move it up to .64volts?
The car runs great but when you come to a stop it feels like it may die. I'm getting frustrated.
Thanks
Bruce H
:cry
My 89 coupe has a rough idle. I've replaced air filter, fuel filter, Disb. Cap & Rotor, Ign. Coil, Pvc Valve, IAC Valve, readjusted idle per manual and this site, checked tps (.54volts) and still roughhhh.
I'm going crazy....I bought a EGR & EGR solinoid which I plan to install this weekend. I'm also thinking MAF(how do I test the MAF?) and maybe the ECM. I've also read in several posts that several people have their TPS set at .64volts. The manual says to set it between .54 and .75 should I move it up to .64volts?
The car runs great but when you come to a stop it feels like it may die. I'm getting frustrated.
Thanks
Bruce H
:cry
Instructor
Joined: Nov 2001
Posts: 117
Likes: 0
From: Macomb MI
Re: Rough Idle Nightmare (Bruce H)
I have the same rough idle on my 87 coupe. Changed plugs, wires, cap, rotor, intake manifold gaskets, removed throttle body and cleaned IAC. Still runs rough at idle, feels like it wants to die. when you figure your problem out please e-mail me @ jimbo10494@aol.com, I will do the same if i figure mine out.
Instructor
Joined: Nov 2001
Posts: 117
Likes: 0
From: Macomb MI
Re: Rough Idle Nightmare (Bruce H)
I have the same rough idle on my 87 coupe. Changed plugs, wires, cap, rotor, intake manifold gaskets, removed throttle body and cleaned IAC. Adjusted the TPS, Still runs rough at idle, feels like it wants to die. when you figure your problem out please e-mail me @ jimbo10494@aol.com, I will do the same if i figure mine out.
Thread Starter
Intermediate
Joined: Oct 2002
Posts: 29
Likes: 0
From: St. Louis Mo.
Re: Rough Idle Nightmare (jimbo10494)
Will Do JIMBO,
If I find the problem I'll let ya know.....I've checked the timing and it was right on the money. I'm going for the EGR valve next and then the o2 sensor. I should add that I have never got any codes for the rough idle. I'm running out of ideas, then it's off to the shop(OUCHHH)!!
Bruce H
:eek:
If I find the problem I'll let ya know.....I've checked the timing and it was right on the money. I'm going for the EGR valve next and then the o2 sensor. I should add that I have never got any codes for the rough idle. I'm running out of ideas, then it's off to the shop(OUCHHH)!!
Bruce H
:eek:
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Drifting
Joined: Aug 2002
Posts: 1,775
Likes: 125
From: Birmingham AL
Re: Rough Idle Nightmare (Bruce H)
.54V is correct for TPS. Check the resistance of your injectors. One of mine went bad and caused this. Its a common problem for the L98. With the harness unplugged, the original greenish-gray Multec injectors should read 16-17 ohms. Onee of mine was at 2.9 ohms. I unplugged it and the car ran great. Maybe time for new injectors.
Burning Brakes
Joined: Apr 2002
Posts: 755
Likes: 0
From: Patterson CA
Re: Rough Idle Nightmare (Bruce H)
I had the same problem for a long, long time along with an annoying code 33. I replaced all the common parts. .54v is correct for the TPS +/- .8v closed, and about 5v wide open. My TPS was set to .54v but wide open I could only measure a little above 3.3v. Thanks to the advice of this forum I replaced the TPS and both problems are gone. TPS is now set at .54v closed and about 4.65v wide open. Some people here were skeptical about the TPS being related to the code 33 but since 65Z01 said it could be related, it was worth the $35 risk to me to buy a new TPS from Autozone.
Just my .02 :cheers:
Just my .02 :cheers:
Drifting
Joined: Feb 2000
Posts: 1,994
Likes: 0
From: Charleston, WV
Re: Rough Idle Nightmare (VetBoy89)
even though the book says you may read up to 5 volts you never want to get there. when you are above 4.65 v or so the ecp senses what is called the deadband area and will sometimes set a code. same for the low side.... less than about .4 volts will set a code ........ Also I have gotten leary of the aftermarket tps....... they aren't sealed as good as the DELCO ones and will screw up after a good engine detailing...... They HATE Armorall.... :lol: :seeya