High Idle at start

[redhotrod]

Hey guys and gals, I need your help.
My car is running totally like crap. When I first start it, it idles way high, around 2600 rpms, then it wants to stall out real quick. I noticed Both my exhaust turbo gaskets are leaking, (the uppipe on the turbo and the downpipe on turbo gaskets.)
Would this make this problem? Are these gaskets available from retail auto parts stores? Any part # if so?
Another question I got is I will be putting on a ta-49 after christmas. Is the ATR 2.5" downpipe bigger than the original downpipe? And will it work on a ta-49 on a hotair?

 

[xxninja]

you would need to fix your your gaskets but that wouldnt control your high rpms at start-up.


most of your high idle issues come from
A) your TPS setting
B) your IAC setting
C) your Maf

do you have access to a scantool?
so you could read the values of the things i mentioned?
if these are not set at the proper values it will throw your idle off alot
i would assume your TPS and IAC are probli out of whack
find a way to measure these values with a scan tool or with a digital voltmeter
look up "setting tps & iac" in the search option

my car, when warmed up idles at like 700-750 rpms

if you find out your values, post them and some1 will steer ya in the right direction





also, dont even think bout that turbo until you get that car tuned properly
new parts dont fix existing older problems

 

[xxninja]

also.......

that t49 isnt exactly gonna slide into place
you Are gonna hafta do some modifying to get it to work and fit

that turbo is designed for the 86-87 cars without that stupid adapter that the hot-airs use, to connect it to the intake.


it can be done, but will take some effort, quite a few guys have done it

 

[redhotrod]

Yep, I have a scan tool, but it isn't helping me much. TPS is at .40v, IAC comes down to 40ish when the idle clears up, but still runs rough. I did find out it seems to operate better with the oxygen sensor unplugged. Whats up with that? With it hooked up, it does get readings jumping all around. Oh, and I did fix my exhaust leaks last night.

I understand that the ta-49 fits the intercooled cars. I just have everything stock (heads, intake, turbo) ported open as much as I can. Plus I have a big camshaft, (comp 212). I want streetability still but more power. I will be putting in some remanufactored 42.5 lb injectors also, but these will be the original pintle style, not disk. Some guy in Florida has a good deal on rebuilt injectors.
Fitting any turbo on my car shouldn't be to much of a hassle for me. I've seen people on here actually fit -60 turbos on their hotairs or bigger.
For the MAF sensor, it gets readings on t-link but I'm not sure if its working correctly, I've heard of tapping on it with a screwdriver or whatever, but it doesn't seem to change anything. How else can I check the MAF?

 

[fireberd350]

i think the ideal TPS range is .44 +/- .2 so try that.
Your IAC's seem good.

The o2 readings are also supposed to jump all around while idling. That is normal.

I think if you tap the MAF it shouldn't do anything. If the car stutters than its bad, however, I wouldn't completely rely on that test. Your MAF could be bad. I have a stock 84 MAF if you need one. Does it pull 255 on the scan tool under WOT?

And the ATR pipe is bigger than the stocker but not as big as a 3"
so thats your call, depending on how deep your wallets are.

also, Is it the stock chip?

 

[redhotrod]

this car ran pretty good for a while, haven't changed anything. Just one day I had to beat on it a little bit to scare a monte owner of what v6 power is capable of and unfortunetly on my behalf, I did something wrong.
I haven't drove it since, just fire it up and move it around in the yard.
The IAC is wayy high when first started, but so is the rpms. Once it warms up a little it will run at a lower idle, just real rough.
I noticed last night when I fixed the up pipe gasket, thats 2 1/2". What size is the stock downpipe? 2 1/4?
I just had a Joe Lubrant 93 chip in my original ecm, but just tinkering around, I hooked up my 86 ecm with a Red Armstrong chip. Both run the same, actually, the 86 ecm throws the rpms up a bit more at first start, I'm thinking because of the MAF though.
Any other Ideas all?

 

[WFO]

sounds like a vacuum leak to me.check all your rubber hoses.

your tps is set too low.42-.46 at idle.anything over 4.4 at wot.

 

[redhotrod]

Hey WFO, I'll get you a pepsi on the rocks and its all on me

Finally got it! Yep, a vacuum leak! My turbo mounting bolt fell out! The one above the adaptor. Idles nice and smooth now. Thanks everyone for the help!

Anyone know the size on the original downpipe?

Why does the tps gotta be around .42? Whats wrong with .40? My high is set at 4.80
This Reds chip I have says I have 58.+ advanced timing? Is that right for idle?

 

[WFO]

[happy gilmore]I AM THE SMARTEST MAN ALIVE!!! [/happy gilmore]



the stock dp is a crinkled up piece of sh!t,probably is about 2.25"...

if you just want to swap it out i'd go with atr's stainless 2.5".chris wilson went 117 mph with his so they flow some air...