Question : no fast idle

[91DOHC284]

howdy

ok so i've had my 92 cutty sitting for almost a year now. I was starting it every month and letting it run for a bit, but about 6 months ago i went to start it and the battery was dead so i just left it. bad move. today, i finally jumped it and it would only give me a fart unless i started it with a little throttle. if i keep my foot on the gas it will run fine above 1500 rpm. if i take my foot off it will idle at about 250rpm (no typo) for about 10 sec then die. its like the fast idle for cold start isnt working. i didnt run it till it warmed up to see what the idle does when its hot. figured i should figure out whats wrong with it before i screw over something else.

so, any ideas? what sensor(s) control the cold start idle?

also, the gas is a little rotten, it was pretty smelly, and the engine has had a miss for quite some time, but i dont think that is related... im pretty sure that has to do with the coil packs...

any input appreciated

[55trucker]

Hi there.....what environment conditions are you exposed to there?....has the car been sitting in sub freezing weather with a dead battery on hand? (that will cause the plates to warp ruining a battery).....before you boosted the car did you replace the battery with a good one? If the battery has NO charge to it at all, the alternators regulator can fail as the alternator is Not designed to supply current to a dead/no battery situation. The battery is actually the controlling item that determines how much current the alternator has to put out to keep the battery sufficiently charged and the system running. A dead battery situation can cause the alternator to go to *full field* to try to charge the battery and this can cause the alternator to fail. If this has happened then you are not running on proper system voltage, and the various sensors will not function properly, which is why it is advised to never try to start an ECM controlled car with a completely dead battery, always put in a fresh one. Which asks the question....do you have any codes entered into the ECM?.....do you know how to *read* them without a scanner? As for the fuel, fresh fuel never hurts, if you can't pump out the old try to mix the old with new (a lot of new)

[91DOHC284]

as for environment, well, im in canada and we just got through the roughest winter up here that i have ever seen. so yes, the battery has been sitting in sub zero temps, but it is only one year old and i have seen batterys go through a lot more torture and still work than this battery has ever seen. and when i jumped it, i jumped it off a running car and did not disconect the jumper cables while the car was running, so the cutty was using the battery of the other car, so i didnt overload the altornator.

as for the codes, well, there are a fair few. i cant remember all of them, but the car always ran good enough with the codes, just wouldn't pass emmisions testing. they werent anything serious the car couldnt function without or anything, but the miss the car has was screwing with the codes quite a bit too. i do know how to test without a reader but i have access to a very high quality reader. however i cant get the car to the reader at the moment as the tranny is blown

but i think the most serious code was the intake temp sensor. the other ones were offspring from the miss, causing the computer to read faulty information and code sensors that are brand new (map sensor, etc)

anyway im thinking maybe the temp sensor is the problem, what with sitting for so long with no fluid movement, it may have gotten all corroded up.
any other ideas? i just need to get it home again, its only a few blocks away, and i have 1st 2nd and 5th gears so it is drivable so long as i can get it to idle properly again

[55trucker]

Well, since you've a manual trans at least you can slip the clutch to move the car....the engine will not idle? ...that is via the IAC circuit only?....if you have your foot on the throttle keeping the throttle body out of the IAC circuit can you keep the engine running?...(just so you can move the car from A to B)...if you can clear the stored codes so you can start fresh that would help...(if the battery was completely dead they may be gone from memory).... don't give up on the temp sensor just yet.......if you have an ohmmeter handy check the sensor for its resistance values....cold (as in -40C should read approx 1kilohm and 130C should give a value of approx 70 ohms). If you believe the battery is still good, try to put a slow deep cycle through it to bring it back to life. Yeah bad weather..... same here where we are...cold and lots of snow that we don't usually see...beginning to suffer from Cabin Fever (so's the car).

[91DOHC284]

well im going to put a battery charger on it and its a very weak charger so it will take about 3 days to fully charge the battery.

like i said, i managed to get it to idle at about 250rpm for about 10 sec without my foot on the gas, but i had to very gently ease the rpms down till my foot was off the gas. with my foot on the gas it will run fine above about 1500rpm. I dont know if thats in the IAC range or not. when i started it there was no codes at all so with the battery being dead it must have wiped everything out.

anyway ill try to find some time to get some work done on it and test some things. see if i can get it to idle before i bring it home. i will undoutadly have more questions fairly soon, and i will update what i find.

[pocket-rocket]

also, the gas is a little rotten, it was pretty smelly,

I wouldn't be shocked if this had something to do with it too.

[91DOHC284]

as stinky as rotten gas is, on numerous occasions i have taken vehicles to emmisions testing with rotten gas and had better results than with fresh gas. i know it sounds strange, but honest to god it really does burn cleaner. but im not saying it cant cause problems. i dont know what effect it has on injected vehicles but on drip pot engines it seems to work just fine, cept for the smell

[pocket-rocket]

I would think it's from the fuels lack of volatility is why emissions seem to test better. Take out the stuff that makes it go bang (the stuff that produces the nasty things sniffers check for) and as the volatile stuff gets lower, so does the production of the things that are checked for. If the tank wasn't full when it was parked, I would also think you have a good amount of water in the tank. Cold weather + low tank = lots of interior tank surface for condensation to form, creating water in the tank. Did you manage to try to pull any codes from the computer while messing with the car?

[Schurkey]

the battery was dead

What are the chances that the ECU no longer remembers where the Idle Air Control valve is, because that's stored in volatile memory and without battery voltage that info is gone. I bet all you need is for the ECU to re-learn the IAC position.

http://60degreev6.com/content/Idle_Relearn