my names is Jordan I go by tiny I have recently purchased a 03 monte carlo ss 3.8l v6 with 200,00 miles on it. it is a beautifull car. I paid $500 for the car because the previous owner did not want to deal with an of the problems the car has (which is very few) first problem high idle , the car occasionally will idle anywhere between 1200 to 3000 rpm. I absolutely hate shutting the car off when it revs that high (but I am not gonna let it run all night) I hooked up my scan toold because there was no check engine light on. the only codes it pulled was evap (ac doesn't work) so I'm assuming this is why there is the code. And the last code was from the CAT but I could not read the code. with the key on while my code reader was hooked up the tp% was jumping anyhere between 4 and 25% s I'm making the assumption the tps is bad. the previous owner informed me he recently had the tps replaced (but new parts can go bad as well)I did a volt drop and the meter Is all over the place backing up my thinking that it Is the tps. the MAF sensore checks out good. so I need some help now. I really need to get this high idle problem fixed. I have done a cyl leak down test all checks out , Vacume tested and no leaks. can the IAC effect the idle? second problem the temp gauge is all over the map (not reading appropriately) so I'm assuming replace it? third problemfuel gauge reads full all the time I have no idea what that could be. fourth and final issue the bright switch for the headlights doesn't work. Replace it ?? I really need some info asap I really o appreciate the help!

 

Bump
There are smarter people than I here, someone may have some advice for you

 

Well it is hard to work on a car with so many issues when you don't know what has started them or why or when.

So I guess the easiest issue is the problem with the Gas Gauge. That sounds like you have a short to ground somewhere in your gauge wiring. That is what it tells me when it is always full.

About the Temp issue with your car on the cluster reading all over the board. This could be related to a couple of things. One bad wiring. However I think it could also be low coolant in the car as well. So I would when cold take cap off look to see that it is full. Start car with cap off and let it warm up. Once you see the pump start to where it take the liquid away from the fill hole, Add more fluid. Once full cap it off.

I don't like to SPEND money on hardware. However I have seen others with High Idle over a bad PCM IN no way am I saying this is your issue. however may want to keep that in mind. It wouldn't hurt to see if you can find a replacement if the price was low enough.

However you may want to check over the Plugs and wires to make sure they are up to par. Also looking over the car for leaks in the VAC is good idea as well.

An issue with the EVAP isn't anything related to your AC. So it could be that you need a new gas cap. Or the gas cap wasn't put on right, Could be Purge Sol, or Charcoal can or any number of things. What EVAP code is it. That may help tell you where the problem is.

James

 

I had a high idle on my Monte for a while. My solution was changing the spark plugs & spark wires.

I would also check your air filter and throttle body to make sure they're not too dirty. If they are, replace your air filter and clean your throttle body.

I did all of this to my Monte and it went from a high idler to idling between 600-700 RPM's. She now purrs in idle.

 

Thank you for the help and the ideas. Took cap off let car run topped off fluid gauge seems to be working properly now. Tested the resistance in all spark plug wires they all checked out. Took out plugs all looked good reinstalled ran a spark tester strong spark in all cylinders! The car did sit for awhile so maybe the tb is dirty. Ive i remove it from the car and remove the sensor and clean it as long as everything is reinstalled correctly can i just put it all on and done? Or does it have to go through a relearn cycle? Did another vacumme test found one hose bad replace car seemed to idle great until it got up to temp now it rev to 3k eeek!