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computer, gas, someone must know


rockfangd

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my 94 cutty 3100v6 is making me very angry so i need some advice. This post may be a little long but i need to be very specifc. So for starters last week i started my car with the car starter just like any other day, came out to te car revving at 3000 rpm, and ipossible to drive. The ses light was on. so come to find out it was the CTS (coolant temp sensor) went bad and was telling the computer it was like 40- so it made the engine go full throttle. So i changed the sensor with a new one. car was good as new, ran better even, so now this is a week later and i go out to start the car this morning and it shot right up to 3000 again, I am like wtf. So i walked to my local parts store and exchanged the sensor for a new one and also bought a IAC, figured i would kill 2 birds with 1 stone, so tonight i did the 2 sensors and started the car up. good right, of course not, now it is revving at 2000 rpm and the SES light comes and goes. things i have done recently are

1.IAC replaced

2. throttle body thoroughly cleaned about 15 days ago

3. new TPS.

4. new CTS x2

5. only use mid grade gas

6.new coil packs and wires and plugs

7. tried to do the idle relearn but it revs too high and tries to take off even with the brake on.

the car shifts fine and does not knock or backfire. If anyone has ever had this problem please post anything, I really need my car and this has never happened before, if i am not specific enough please tell me., Is my computer bad, i have no idea, I try to do the diagnostics on it but it is a 94 and i cannot seem to be able to get the right scan tool for the obd :sad:. Thanks to everyone in advance for all the help

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well i did take it off when i cleaned it but i reused the gasket because it looked good, and it ran fine after i did the job, Maybe i could change it though if it could fix this prob. Thanks

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I would agree that it sounds like a vacuum leak, but you really need to know what the SES is on for.

 

If its a 94 then you should just have to short 2 pins at the ALDL connector, and retrieve the codes via the flashing SES light. You can look the code definitions up online.

 

Definetly replace the throttle body gasket either way... you should always replace it if you take it off. You can check for vacuum leaks by spraying brake cleaner all around the throttle body, at the UIM gasket, and the LIM gasket while it is running (preferable at the lowest idle you can get it at). It will idle down/rough and you will get a pungent smell from the burning brake cleaner if there is a vacuum leak where you are spraying. You should also remove each vacuum hose connected to the UIM one at a time, and plugging the port on the UIM, see if the idle corrects itself. If you find a port that does, trace the hose that was connected to it for leaks.

 

On 3100's, there is a vacuum tee that connects into the UIM right next to the throttle body, and is held down by the accelerator cable bracket. It supplies vacuum to the PCV valve and the evaporative emmissions system. The grommet in the UIM is prone to going bad, and will cause high idle. A piece of a spark plug boot makes an excellent grommet.

 

Also, have you checked the accelerator linkage itself for binding? Are you sure the butterfly in the throttle body is closing all the way?

 

If you find no vacuum leaks, your code may be the key to telling you what is causing the high idle.

 

I remember on a 90' GP, had erratic high and low idle, with a flashing low coolant light and intermittent speedo.... it was the ECM

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I would agree that it sounds like a vacuum leak, but you really need to know what the SES is on for.

 

If its a 94 then you should just have to short 2 pins at the ALDL connector, and retrieve the codes via the flashing SES light. You can look the code definitions up online.

 

Definetly replace the throttle body gasket either way... you should always replace it if you take it off. You can check for vacuum leaks by spraying brake cleaner all around the throttle body, at the UIM gasket, and the LIM gasket while it is running (preferable at the lowest idle you can get it at). It will idle down/rough and you will get a pungent smell from the burning brake cleaner if there is a vacuum leak where you are spraying. You should also remove each vacuum hose connected to the UIM one at a time, and plugging the port on the UIM, see if the idle corrects itself. If you find a port that does, trace the hose that was connected to it for leaks.

 

On 3100's, there is a vacuum tee that connects into the UIM right next to the throttle body, and is held down by the accelerator cable bracket. It supplies vacuum to the PCV valve and the evaporative emmissions system. The grommet in the UIM is prone to going bad, and will cause high idle. A piece of a spark plug boot makes an excellent grommet.

 

Also, have you checked the accelerator linkage itself for binding? Are you sure the butterfly in the throttle body is closing all the way?

 

If you find no vacuum leaks, your code may be the key to telling you what is causing the high idle.

 

I remember on a 90' GP, had erratic high and low idle, with a flashing low coolant light and intermittent speedo.... it was the ECM

anyone know exactly how i can diagnose the SES light on my 94. Also i can probably do the idle relearn but is it safe to have it in gear and held for 5 minutes, i do not want to do more damage. Also why would it run fine for almost a week then comletely go nuts again. Also i hear absolutely no hissing from under the hood and i have moved lines to try to see if idle changes but it doesnt. ???/

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On 3100's, there is a vacuum tee that connects into the UIM right next to the throttle body, and is held down by the accelerator cable bracket. It supplies vacuum to the PCV valve and the evaporative emmissions system. The grommet in the UIM is prone to going bad, and will cause high idle. A piece of a spark plug boot makes an excellent grommet.

 

My gf's Regal has that exact same problem. The seal/grommet has worn away. I already used some gasket material to make a makeshift gasket, but it still moves around.

 

Do you have a picture of this spark plug boot trick?

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well there is a line that has been funny for the 3 years that i have had the cutty. it goes from the air cleaner to directly below the coil packs at the rear of the engine, is that what you are talking about, it has never caused a prob but i know it is only setting in the hole, also linkage is fine, pcv valve and line is fine, butterfly valve seems to work freely

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My gf's Regal has that exact same problem. The seal/grommet has worn away. I already used some gasket material to make a makeshift gasket, but it still moves around.

 

Do you have a picture of this spark plug boot trick?

 

No pictures, but its simple. Take any sparkplug wire from a 3.1/3100, cut about 3/4" off the very end of the end that is meant for the plug. Then take out the top two 10mm bolts that are holding on the accelerator cable bracket and bend the bracket enough to give you access. Pull out the tee and discard the old grommet. Push your new grommet into the hole about halfway, then push the tee in and push it all in flush. Reassemble and your good to go.

 

well there is a line that has been funny for the 3 years that i have had the cutty. it goes from the air cleaner to directly below the coil packs at the rear of the engine, is that what you are talking about, it has never caused a prob but i know it is only setting in the hole, also linkage is fine, pcv valve and line is fine, butterfly valve seems to work freely

 

No that line is just a breather tube, it won't affect how it runs. The grommet I am talking about is directly on top of the intake plenum, right next to the throttle body. The black bracket for the accelerator cable is covering it. Follow the tube connected to the PCV to the top of the throttle body, that is where the grommet is located. Its a high failure item.

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My gf's Regal has that exact same problem. The seal/grommet has worn away. I already used some gasket material to make a makeshift gasket, but it still moves around.

 

Do you have a picture of this spark plug boot trick?

 

No pictures, but its simple. Take any sparkplug wire from a 3.1/3100, cut about 3/4" off the very end of the end that is meant for the plug. Then take out the top two 10mm bolts that are holding on the accelerator cable bracket and bend the bracket enough to give you access. Pull out the tee and discard the old grommet. Push your new grommet into the hole about halfway, then push the tee in and push it all in flush. Reassemble and your good to go.

 

Thats pretty similar to what I had done originally actually!

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thanks for the ideas.what i am going to do is when i go to take off the TB to put on the new gasket i am going to upgade to the 3400 TB, i ordered the new gasket and a thermostat at the same time. Is it true that the thermostat is a difficult job on my 94?

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Is it true that the thermostat is a difficult job on my 94?

 

Nah its not bad. There are two 13mm bolts holding on the housing.The top bolt has to come all the way out. The bottom bolt has to come about 3/4 of he way out. The housing has a slot cut in the bottom hole to make it easier to remove the housing.

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well i got some relief from the situation. When i put the new IAC in There are 2 steps that i had to make sure to do to reset the ECM. I had to turn the key to on for 5 secs then off for 10 secs. then start the car :mrgreen: problem solved A dur. lol. Then it states to drive it at 40 mph for at least 5 mins and it will automatically adjust. Thank god, but the last time i thought i had it fixed i thought wrong. I even added my Ram air that i have been waiting for, so the only thingi have to do is to build a surround box to keep the heat out :mrgreen: little bit of a power increase. still does 95 like its nothing but i do not want to break something lol. also if someone knows what this connector in the last pic is for on the ub3 cluster please post. thanks

 

[attachment deleted by admin] Removed to free up storage space.

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