Cold Idle Problems

[95GTV8]

I have a 1995 GT with the mods listed in my sig. This problem has only occured when it's cold out, i live in washington state, so when the temp is from 30-50's my car is unhappy. I turn it on, and i have to have all accessories off, warmer, stereo, even tho my battery guage reads fine, if i don't let it sit for atleast 45 seconds idling it just craps on me. If i try to put it in gear and start maneuvering out of my driveway before the 45 second grace period, when i have to change from 1st to reverse, the second i stop the car to do this, and im not accelerating the car dies, and then i have to just rev the thing, and keep the gas up while maneuvuring out of tight spaces. It's a big pain in the ass and then sometimes it will die if im idling at a stoplight. My question is, why if i don't let it sit for 45 seconds to 1 minute will it crap out on me the after i put it in gear and then once i take it back out and im not giving it gas. I think 45 seconds is a long time to wait aswell. Now the idle is like this, i turn it on and it idles fine for a little while, then it starts to get low, and then a sudden surge up to bout 1200 rpm, then back down to 600 etc, slowly this evens out and the surges decrease in length and it idles at about 700, which seems low. It's a huge pain in the ass trying to get out of my driveway, when i have to make tight maneuvers but i also have to be flooring it to keep the car alive.

If anybody can help me with this it'd be greatly appreciated. Merry Christmas!

 

[mo_dingo]

Have you cleaned your MAF and IAT sensors lately??? If not, you really need to. They are very sensitive.
Scott

 

[95GTV8]

allright i'll try and find some info on the IAT, i know how to clean the MAF with some electrical contact cleaner so i'll get to it. ty.

 

[legalize420]

the idle going up and down is called surging/hunting ( most call it surging ). go to the 5.0 tech section and there is a sticky of thing that should be checked. i have hot start surging now and im hoping the coolant temp sensor just needs to be changed. i just ordered it yesterday, maybe i should have got the IAT also . either way good luck, and check out that stick as a starting point .

 

[HISSIN50]

The fox ACT is not nearly as sensitive or likely to cause issues as the SN95 ACT (hence why the fox guys dont recommend it all-that-often compared to the SN95 crowd). The sensor is in the lower intake on a fox, vs the air tube on the SN. Scott's idea to clean it is very good (checking the ECT is good too).

I would pull codes first. 45 seconds - 1 minute might be about the time it takes for the O2's to light off - and that might help get the fuel trim a little cleaner to help with the surging. What is your warm idle setting?

Good luck.

 

[95GTV8]

warm idle setting? I'm not quite sure what you mean. When i drove the car in the summer, it started up fine, and i could immediately put it into gear and drive away and it wouldn't ever die. If your asking what my idle was when it was warm out, it was about 900 during the summertime. During their summertime their was idle surging either.

 

[mo_dingo]

Oh good point, you should verify your ECT voltage and compare it to the temperature of the engine. There should be a graph somewhere here.

But yeah, maf and iat is where I would start. Another would be if you haven't done a tune up, you should. Check out all the plugs/wires/cap/rotor contacts and such.
Scott

 

[drakesdad]

In the boat with you, used the car start last night and listen to the surging idle go up and down until it got so low it stalled, three times. Then it stayed running after that. I think I will try the cleaning of the maf as well.

 

[95GTV8]

well, i've gotten a tune-up recently, but i will begin with the MAF, and the IAC, i've noticed the IAC is on the throttlebody, and i have a 65mm FMS TB, with all that stuff on it, so i will throw that on there, and make sure to get it all cleaned out 1st. Only problem with the TB is, on the side where thers the metal swivel thingy, it's where the line connects to it, and opens it and closes it, it was broken and re-attached. It looks like it was re-soldered/welded back on, so i need to make sure it's strong enough so that it doesn't snap off with the pressure from the line.