Why Does It Die??

[Rads]

I finally got my 85 running and I need to tune it. I have Turbo Link but, I don't know much about what reading I should be getting. I have the TSP set at .39 volts at idle. Right now I can only get the car to run if I remove one of the vacum lines. I think the problem lies in the IAC. I get a reading when the car first starts but, as the car idles down the IAC drops to 0 and the car dies. I have tried to adjust the IAC set screw but, there is a fine line between running at 2500 RPM and the car killing. I have tried two differen t IAC's and both do the same thing. Any help would be great!! Thanks

 

[cool 84]

What mods do you have?

 

[SLOW_85]

TPS needs to be .42-.44
.39 is prolly ok, kinda on the low side. What's your wot reading?
Needs to be above 4.5 volts. Check with the motor not running.
I usually set mine @ .42
What vacuum line are you removing? Might have some routed wrong.

 

[Rads]

I checked wot and it was fine. When I pull any vacum line off it will idle better. It idles best with the vacum line from the intake off.

I have the following mods: adj, fuel presure reg., Intercooler (aftermarket), 36# injectors, stock turbo that has been reamed out, Turbo Tweek chip (just put this in this week).

Thanks for the responses!!!

 

[SLOW_85]

Could be the aftermarket intercooler causing probs with the idle.
Really should idle worse with any vacuum line pulled.
I assume the chip matches the injectors.
Have you tried resetting the ecm. Un-plug the orange wire lead off the battery. Then plug back in.
That will clear the ecm and it will learn new perimeters.
Also will cause the car to run rough for awhile till it adjusts again.

 

[Rads]

The chip was custom built to my specs. so I think I am OK there. I will try to clear the ECM. I'll let you know if it works. Thanks again!!

 

[BRAD_PADGETT]

RAD- I would get a scan tool so that you can give the members real info. Without a scan tool you are "Fying Blind" with and any info you give on this site will be bogas. The advice you receive without scan tool readings will only empty your wallet. Just my two cents- Brad the CPA.

 

[cool 84]

Could be the intercooler. When I first got mine, problems were lack of throttle response off idle, surging at idle, stalling at idle, and a bad hesitation and somtimes stalling when revved from idle. I ended up moving the throttlebody to the pressure side and it cured the problem.

My theory was that when you rev it or even when the computer tries to kick up the idle, the gas gets there before the extra air and causes the stalling/hesitation. By moving the TB to the pressure side near the intake, you eliminate this problem.

 

[SLOW_85]

Here's the quick reference quide from gnttype.
scan numbers should be close to these.
http://66.94.229.32/myresults/mycac....com/myweb?ei=UTF-8&dg=0&tag=auto+folder&b=40
If you can get some t-link info, that would be helpful.

 

[TurboBuRick]

Could be the intercooler. When I first got mine, problems were lack of throttle response off idle, surging at idle, stalling at idle, and a bad hesitation and somtimes stalling when revved from idle. I ended up moving the throttlebody to the pressure side and it cured the problem.

My theory was that when you rev it or even when the computer tries to kick up the idle, the gas gets there before the extra air and causes the stalling/hesitation. By moving the TB to the pressure side near the intake, you eliminate this problem.

Don't you mean moved the MAF?

 

[cool 84]

No, on a hotair the throttlebody is before the turbo. Which means when you add an intercooler you now have 15' of plumbing plus the intercooler between the TB and engine. Throttle response is not good to say the least.

 

[Rads]

Thanks for all the responses! I cut the power to the ECM last night to reset the ECM and it did not make it any better. I will get some info. from Turbo Link and seeif it makes sense to you guys.

Slow 85, thanks for the wed site. I must be doing something wrong because all I get when go to that site is a personal yahoo page. Is there a certain place I should look? Thanks again!

Cool '84 do you have pics on how you moved the throttle body. I would really like to see how this is done. Thanks!

 

[SLOW_85]

Slow 85, thanks for the wed site. I must be doing something wrong because all I get when go to that site is a personal yahoo page. Is there a certain place I should look? Thanks again!

GNTTYPE.ORG site is still down.
I have most it cached on my web.
Hopefully they will get it back on-line soon.

 

[tenright]

Slow 85, thanks for the wed site. I must be doing something wrong because all I get when go to that site is a personal yahoo page. Is there a certain place I should look? Thanks again!

Sounds like your computer is runing like your car lol

Post a list of your turbo link scan readings after the engineis warm...most importantly, BLM, tps, and O2, also need to know your fuel pressure with the vacuum line off.....

 

[BRAD_PADGETT]

Rads- You really have to post your mods in your signature as well as real scan tool numbers. Otherwise you are only going to get bad info here and empty your wallet. IMO and after market intercooler on a hot air is a tuning nightmere. Thats why I avoided it at all costs. With todays technology the Razor Alky kit has rendered the hot air intercooler a dinosaur. Might think about dumping it because nobody makes them nor does anybody know how to tune it. Just my 2 cents. Brad

 

[cool 84]

Rads- You really have to post your mods in your signature as well as real scan tool numbers. Otherwise you are only going to get bad info here and empty your wallet. IMO and after market intercooler on a hot air is a tuning nightmere. Thats why I avoided it at all costs. With todays technology the Razor Alky kit has rendered the hot air intercooler a dinosaur. Might think about dumping it because nobody makes them nor does anybody know how to tune it. Just my 2 cents. Brad

The intercooler is no tuning problem at all. You just can't have the TB behind 15' of plumbing. Once you eliminate that problem you'll find better throttle response than it had stock without the intercooler. Alky is great but it doesn't take the place of an intercooler. I think this guy is on the right track still.

 

[darkred87T]

Right now I can only get the car to run if I remove one of the vacum lines.

It sounds like it's running rich. My car has a similar problem and I know it's way too rich. When I pull a vacume line off, it actually smooths the idle out for a few seconds before the ecm loads it up again. Did you check for vacume leaks?

 

[Rads]

Sorry for not getting back sooner. I am working on getting numbers from turbo link (having a problem with my networking). The car does seem to run very rich. Here is the odd thing, the motor runs very rich and almost seems to have a miss when the MAF is hooked up. If the MAF is disconnected the motor idles and runs well at low rpm but, as soon as you try to work the engine it starts to bog down. I have checked all the vacum line and they are fine. I will have some hard numbers soon from T.L. Thanks for the responses

 

[tenright]

Thats a good place to start, if your car runs better without the MAF that is a really big MAF is bad sign...Just a guess but did you buy a rebuilt MAF? cause about 1 out of 10 of those are good...Best way to insure you have a good MAF is to convert to a translator and LS1 MAF.....You will probably spend just as much trying to get a good rebuilt MAF as you will to convert.

 

[darkred87T]

I bought an LS1 MAF and translator for mine thinking it was the problem and it wasn't. Not that it's a bad investment or anything but your problem could be else where. There is a sure fire way to eliminate a vacume leak. With my 87, I pulled the rocker assemblie off to shut the vales, disconnected and plugged off the PCV line and took off the EGR and selaed off the port. Then, I got a 2" rubber cap to go over the throttle body. I then took an air hose and inserted it into one of the vacume lines with about 10PSI. I know this sounds crazy, but if air doesn't bleed off, you definitley don't have a vacume leak. I hope that made sense. Unfortunatley, my car seems to have good vacum so I probably have some other problem. I would eliminate the possibilty of a vacume leak first.