My RS 5.0 is starting back up with the idle problems again. It doesn't like to start up without a little gas. Sometimes the car won't idle by its self, and I have to give it a bit of gas and idle it manually at approx 1200rpms till it warms up. After it warms up it idles at around 1000rpm When it's like this I often find myself stalling when turning into an intersection or while turning out of my drive way.

When it's not like that, it's starts up and idles at 2500-2800rpm until it warms up (at least accoring to my crap speedometer), and even then its between 1200-1500rpm. When it is like this It doesn't stall.

I have recently changed the oil, and given it a full tune up with Rapid Fire spark plugs, and I haven't modded the engine in any way. It was running really good right after I gave it the tune up, and it stopped running rich. About 3-5 weeks later it started with the idling problems and it's running on the rich side now.

Anyone got any advice for me? Thanks!

 

Vac leak? If not is IAC functional? Throttle shaft to TB worn?

Idleing at 2800 means it is getting air from some source other thanopened butterfly..

 

Definitely check all vacuum connection, had the same problem with not having the vacuum connections hooked up right, and when i did, they were cracked and leaking, swapped out to new lines and all good. Let me know if it helps.

 

no codes????

 

I'll def. check the vac lines. Don't know how to read codes 92. Sorry. Not sure where those show anyway.

 

look above the tach on the dash when the car is running.

 

You mean in the Engine Check light and IMFL Rest area? Are those the codes your thinking of?

 

Mine was doing the same thing. I found several vacuum leaks and I replaced the TPS and poof all better. I love my car but I miss a carb.

 

after you start the car and it is running does the check engine light stay on or go out.

 

Take car to an AutoZone or Advance auto and have them check codes....Free

 

Sometimes it stays on for a little while and then goes away. I'll take it to Auto Zone to check for codes.

 

When it goes on and off, its normally a sensor. My map sensor did this and made it so the car idled like ****. All due to me swapping the engine and didnt hook up the vacuum lines correctly, and leaving one on the TB open... not my proudest moment.

 

they can't help you because you have an OBD1 system

you need to simply use a paper clip on the ALDL port and read the flashing codes

 

Forgive my incompitance. ALDL port?

 

asking is learning, nothing wrong with that

I may be acronym challenged however I believe it's

Assembly
Line
Diagnostic
Link

if you are in the drivers seat it should be near your right knee

try doing a search here on this site for flashing codes but, and this is memory because I have not done it for a while so double check me to be safe

the top 2 right pins get jumpered with a paper clip or piece of wire

turn key to run, CEL light should flash once, then twice, and then move on to any other codes such as flash 4 times and then 3 times

it will keep flashing as many codes as were stored and then return back to 12 and start all over again.......or is it 22?

that's why you need to confirm my memory

 

Thanks. I'll try that later.

 

Well, car is getting a bit wrse now. I little tiny bit of white smoke is coming out of the tail pipes at start up and often when warming up, and the idle is even higher. I'm going to check the codes tomorrow and do a sea foam treat ment to try and clear any cloged or gunked vacume lines/fuel system.

 

I bought a 91 Cmaro with 3.1, It died every time I stopped. There was black soot in the tailpipes so I replaced the O2 sensor, that fixed it.

 

Yah. Just read the codes. 12, 13, 11, 14, posible 21 (I don't remember reading this but it would make sense with the symptoms I've experianced and the code 23), 22, 23, 24, and maybe a 25. Most of those can be ignored. But, code 23 (Throttle body position sensor error), would explain the high/off idle. And the Oxygen senor error (code 13), would also explain allot. The Oxy sensor I can take care of, the throttle body position sensor I have no experiance with.

 

13 and 14 yes you need them. 12 means ecm is working. 21, 22,23,24 these all need to be taken care of.

 

How do I take care of the the throttle body position sensor?

 

the tps is located to the right of the IAC on the throttle body, replace it and the code should clear if that's what was causing the issue

 

do you have a meter?? remove the old one and install the new one with the battery disconnected. this all sure seems like a harness issue. like a feww bad grounds and the pink and black wire that gives ignition power all over the engine has a break in it.

 

Do you have a multi meter? If so you can check TPS with a jumper/adapter made by yourself to attach meter. Look for smooth voltage linear increase from .50v or so to 4.5 as you open throttle. key on engine off. Somewhere here is the diagram of the leads you need to jump to. I forget.

 

Yes. I have a meter. Wait, what? That whole last bit confuses me. When you start getting into car electronics my brain blows a fuze.

 

You attach the multi meter to 2 of the 3 leads to TPS. with key on engine off or engine on it will read .50 or so at throttle closed. Then sloooowlllly open the butterflies and it will smmooothly increase in V's to 4.5. If it is erratic on the opening of BF's then TPS may be defective.

 

That I can understand. Thanks mate.

 

Hmmm. I got confused somewhere. Can someone tell me where the TPS is, just so I can be sure I'm doing this right.

 

attached to side of the throttle body where the linkage is. drivers side

 

Ah.

 

uhh. For some reason I'm not seeing it.

 

I can't find it.

 

you should post up a picture of what your seeing and we can highlight it for you

 

It should be right in the area where i circled red. There should be a black sensor with two torx screws that attach it to the passenger side of the throttle body. Good luck!!!

 

Yup, standing infront of the car, it's on the pass side of the throttle body, it looks kinda like a black half circle, has a connector plugged into it

 

Thank you. You can see where I'm getting confused. I know where that sensor is. It's EXACTLY WHERE I THOUGHT IT WAS. On the PASSENGER side. Uhg. Alright. Lets try this again.

 

Sorry mine was on drivers side but that is a Vette. My 7.4L TB is in fact on pass side!