Mechanics

MY CAR IDLES TOO HIGH AT START.

1995 Buick Century • 165,440 miles

My 1995 Buick Century idles too high after I start the car. I find no vacuum leak However I do have a check engine soon light on and I don't know if the Idle position sensor is doing it. I have a the newer 3.1 V6 SFI Engine not the V6 3.1 MFI. Before all this, My Car was given to a friend of my wife's and we told her now to let no body, and I mean no body to touch the car for any reason. Well, she didn't obey, and her children tried to steal it and they tried to jump another car and the positive + jumper connector touched the air cleaner cover, (metal) and cause a engine fire and instead of diconnecting the negative wire connector - they looked on and let the wire burn until they got some dirt and stopped the fire, in 2 different places. My wife and I had the car towed to our house and there I bought a whole complete engine wiring harness and replaced the burnt one. Does that make you mad! Help me with this problem and get this car up and running again like it once did. Also can it be the ECM? How can I check if its bad? Thx u.
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Ao7777
July 22, 2012.




With what you describer, yes, I believe the ecm is fried. I would replace it as if it is not bad now, it will be.

The idle air control may be your issue with the cold high idle.

Roy


ASEMaster6371
Jul 22, 2012.
Thx u ASEMaster6371. You still didn't answer the question about how to check if the ECM is good or bad? I may have to borrow a ECM with serv number that matchs mine to see there any difference. Thx u.


Tiny
Ao7777
Jul 22, 2012.
You cannot unless you have the equipment. A real scan tool that can monitor sensors. Looking at the inputs and outputs and there needed and real values.

Roy


ASEMaster6371
Jul 22, 2012.
Is the Idle air control is the Throttle position Sensor? If not, tell me were it is located. Also, what should I start 1st? Get an ecm or get a new TPS? I believe the TPS is working, need to know how to test the TPS.


Tiny
Ao7777
Jul 22, 2012.
To test the tps get a dvom. There are 3 wires one is a ground one is a 5 volt ref voltage. And one will be the signal wire. There is no adjustment for it on this car. The koeo voltage will range from about.2 volts to about 4.9 volts at wot. The best way to test it is with a grafing meater.


Djcl
Jul 23, 2012.
So far, I found the fuel leak, from the fuel intake hose, so I replace both the intake and relief lines. As soon after I started the car, I did smell some fuel yet no leaks from the hoses until after I discovered a fuel leak from under the plenum intake manifold but not from the hose were is screwed on at. Can a injector be leaking and cause the idle to idle high (vacuum leak)? I had some small trouble putting the plenum intake manifold on lining up the holes before screwing down the screws. Yet nothing seemed to binding before installation of the plenum.
What did I do to cause the fuel leak?


Tiny
Ao7777
Aug 5, 2012.
I forgot, when I started the engine, I had the TPS disconnected and yet no change in idle. However, I shut off the car and reconnected the TPS and disconnected the IAC valve and again started up the car and the idle seemed much lower but when I reconnected the IAC valve, the idle shot up again like it was doing before. Can the IAC valve be the problem or that fuel injector leak?


Tiny
Ao7777
Aug 5, 2012.
Hello, I am back. I changed the ecm and still the problem exists. I have a friend who is a mech and he told me that the TPS is the problem. I bought a obd1-obd2 scanner and its on the way. I will find out what is the problem is.
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Tiny
Ao7777
Aug 18, 2012.
I recieved the Scanner and get to find out, through tech support, that the scanner I bought cannot read the ecm for this car. I need to know what scanner or code reader do I need to read the codes.


Tiny
Ao7777
Aug 23, 2012.
I had a lot of dought about their answers about my new scanner. However, I found out that my obd1 scanner does not work and has now power. It also has a factory Security Alarm but I removed it. But my 12 pin connector has no power and only has 3 wires coming out from the back of the obd1 connector. No "B" terminal, I have a obd1 scanner and does not read it.


Tiny
Ao7777
Aug 25, 2012.

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