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Technical => Engine Tech => Topic started by: jpc647 on August 04, 2008, 12:59:30 PM

Title: 1987 turbo coupe high idle
Post by: jpc647 on August 04, 2008, 12:59:30 PM
My 1987 turbo coupe has a high idle when in park and nuetral. Its only after its been driven a little bit and is warm.

Am i supposed to let the engine idle high after i've been driving the  car for turbo cooling purposes?

I tried letting the car idle for a couple of minutes but it didn't idle down. Any ideas?


John
Title: 1987 turbo coupe high idle
Post by: Chuck W on August 04, 2008, 01:35:44 PM
Is it throwing any codes?
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 04, 2008, 02:42:10 PM
No. the engine light does come on if i accelerate hard and let off the gas. It stays on for a couple of seconds and turns off.
Title: 1987 turbo coupe high idle
Post by: Chuck W on August 04, 2008, 02:45:48 PM
What is your definition of "high idle"?  They will idle higher in Park and Neutral normally.

The IAC valve may be sticking (the canister-looking thing bolted to the intake near the throttle body).

Odd that you're not seeing any codes, but getting a CEL.
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 04, 2008, 03:48:04 PM
A high idle is around 2000. Maybe a bit under. It only does that if the car has been driven with the turbo spooling. If i dont put my foot into it it wont do it. If the turbo spools up once itll idle high. Is this supposed to happen? How long does it usually idle like this?

Is it safe to shut the car off when its doing this? Whats its purpose?
Title: 1987 turbo coupe high idle
Post by: Chuck W on August 04, 2008, 03:53:30 PM
There is no purpose, something is not working properly.

You say you did run codes and got the "11" "All clear" code?

Remove the IAC and clean/blast the valve out with carb cleaner.  Sometimes they hang up.

Check your TPS voltage at well.
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 04, 2008, 08:06:27 PM
I haven't checked for codes, but seeing the check engine light only comes on and off occasionally i figured it wouldn't be throwing codes.

I cleaned out the IAC to no avail. It may have helped a little bit. I put 60 miles on the car and the check engine light only came on twice. For about 10 seconds each time. I was doing 50-55 at about 2000 rpm. It comes on if i let off the gas, and the car starts to decelerate.

Where is the TPS on these cars?

and it has nothing to do with the throttle linkage. Its bottomed out, and in park the tach still winds up to around 2000.

I figured this might be to let the engine spin after the turbo spools. I read somewhere on this site never to just shut the car right off after driving it. But maybe its more serious.
Title: 1987 turbo coupe high idle
Post by: 88TurboCoupeman01 on August 04, 2008, 08:20:35 PM
Ya your suppose to let  the turbo stop spoling by letting the car idle for a minute or two before u cut the car off this goes for all Turbo Cars.
Title: 1987 turbo coupe high idle
Post by: Chuck W on August 04, 2008, 08:55:44 PM
Run codes.  Otherwise you're just guessing. Period.  Until you run codes and at least get that info, no one else is going to be able to help you either.



There is NO coding in the stock ECU that raises the idle for turbo "cool down". 

And the turbo doesn't  "spool" at idle....
Title: 1987 turbo coupe high idle
Post by: ipsd on August 04, 2008, 11:36:57 PM
If the light has come on and went of there still might be a codes stored. The tps is on the throttle body on the back side. Check and make sure that it is set at about .97volts. Then the only other thing that comes to mind would be that maybe the temp sensor is dead or the wires to it are shorting and causing it to think that is it cold. Never can tell best to get out there and look into it like we've told you.
Title: 1987 turbo coupe high idle
Post by: Chuck W on August 05, 2008, 07:09:53 AM
Codes will be stored with or w/o a CEL...
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 05, 2008, 10:11:57 AM
Alright. Now autozone only has a code reader for obd2. Do i have to take it to a garage? do they make a cheap code reader for the older cars?
Title: 1987 turbo coupe high idle
Post by: Chuck W on August 05, 2008, 10:20:31 AM
You don't need a reader....

Go HERE (http://www.turbotbird.com/) and read the procedures for getting codes on the Tech Articles page....
Title: 1987 turbo coupe high idle
Post by: *MAYHEM* on August 05, 2008, 08:38:12 PM
Codes, codes, codes, codes....
 
JeSUS!!!
 
With all the turbo cars on here I'm sure somone has run into this problem before. Why can't some one just say, "Hey, that happened to me one, turned out the IAC was sticking."
 
No. Everyone has to have CODES so a computer can tell you something that someone already knew.
Title: 1987 turbo coupe high idle
Post by: Chuck W on August 05, 2008, 09:31:47 PM
I gave him the IAC option...he tried it...no dice. 

Working on an EEC4 car...you are shooting in the dark without the codes, 2.3T, 5.0 or not.  They are called diagnostic codes for a reason.

We could continue to guess...he could continue to throw parts and time at it...and maybe, eventually the problem might be found.

Coming in looking for a solution to an engine issue, CODES should be almost as mandatory as what car you are working on, period.
Title: 1987 turbo coupe high idle
Post by: TurboCoupe50 on August 05, 2008, 09:54:06 PM
Quote from: Chuck W;230778
Coming in looking for a solution to an engine issue, CODES should be almost as mandatory as what car you are working on, period.

X2... Just like when you pick up your dry cleaning, "no tickie, no laundry"
Title: 1987 turbo coupe high idle
Post by: ipsd on August 05, 2008, 11:05:25 PM
Sometimes it is just best to GET UP GET OUT THERE AND DO IT! Codes aren't a guarantee they are there to give you and idea on witch circuit to look at. That by no means that if it says MAF is out of range that it is the MAF that is bad. What they are saying is that the MAF signal is not within spec according to the other sensors that they have info to compare it against. Why else could it tell you MAF and it turn out to be the TPS. Because the MAF reading was off according to the amount of of signal that it is getting from the TPS. So yes codes help A LOT! You still need to do some good ole checking to find out what is what before you just start dropping $$$ on parts. Why do I here so many times that the code said this and I replaced that part and now I still get the same Code. Because you use bought the part and didn't do the right thing and test to find out witch part in that circuit is really making that code come up. That is why, and that is why a real mechanic will find the problem and fixes it. The shade trees are the parts swappers. So what do you wanna be.
Title: 1987 turbo coupe high idle
Post by: Superdavesds on August 06, 2008, 12:06:11 AM
HERE HERE IPSD. That was a great explanation. I have been victimized too many times by being a parts swaper. I wright programming for a living and if ever I could be smart enough to right an engine manegment program, my fault program would tell you what is wrong. I seriosly think that these systems are designed to confuse so that you will buy the extra parts, stay confused and get a mechanic, or just go buy a new car. I try my best to wright my programs where no one else can read them. That away I have value to my employer. They think I am smart. With the help of these forums I am getting smarter. Although my car still runs like . lol
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 09, 2008, 01:29:34 PM
After finding a code reader,I got some codes from my 1987.

15, 21, 22 and 14 were reported.

It was wierd the codes went 15, 21, 22 15, 21, 33, 14, 14.

I looked up the codes:
14: Profile ignition pickup circuit failure
15: Read only memory test failure
21: ECT sensor faulty
22: Barometric pressure/Map sensor faulty.

Not to sound stupid, but I'm more worried about codes 21 and 22. What should I check to correct this problem? Any suggestions?
Title: 1987 turbo coupe high idle
Post by: ipsd on August 09, 2008, 02:12:50 PM
ECT sound like that coudl be it but you'll never know unless you test the reading that the sensor is giving.
Title: 1987 turbo coupe high idle
Post by: Blackout on August 09, 2008, 02:33:00 PM
Codes are essential. 

Throwing parts at a car is just wasting money.

To me, FWIW, it sounds like the TPS voltage needs to be re-set.  Also, the base Idle has to be re-set.  The IAC actuator may not be working right, clean valve or not. The ECT or IAT could be giving bad info to the computer. Your fuel pressure regulator could have ruptured..  See how expensive just throwing parts at a car is?  Check the codes, it will at least set you in the right direction.

From the code you have, the ECT could be the culprite.  Start off my VERIFYING that the base idle/tps is set up correctly.  If it is, the next step would be the ECT.  The absolute bottom on the list would be the BAP.  They don't go bad very often, and you would need a meter that can read frequency in order to test its output.  I wouldnt worry about the 14 for right now, get the other stuff figured out and then go from there.
Title: 1987 turbo coupe high idle
Post by: Chuck W on August 09, 2008, 04:04:03 PM
Was the car up operating temp when you got the codes?

Double-check your TPS voltage as mentioned and perhaps look deeper into the ECT.  I've rarely known those to fail though.
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 09, 2008, 04:08:27 PM
The car must have been at operating temp. It was driven for over an hour for a distance of approx. 50 miles.

My temperature gauge rarely moves. After that trip it was barely over the blue line on the bottom of the temp gauge.
Title: 1987 turbo coupe high idle
Post by: 88TurboCoupeman01 on August 09, 2008, 04:26:41 PM
go pick up a code reader from AutoZone for around $100 bucks then get the Ford OBD I addaptior from Auto Zone to. Or buy the Ford OBD I addiptor and let Auto Zone connect to the code reader.
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 09, 2008, 09:41:55 PM
I already have the codes. See page 2.
Title: 1987 turbo coupe high idle
Post by: Chuck W on August 09, 2008, 10:08:44 PM
Quote from: jpc647;231333
The car must have been at operating temp. It was driven for over an hour for a distance of approx. 50 miles.

My temperature gauge rarely moves. After that trip it was barely over the blue line on the bottom of the temp gauge.


OK, well check your TPS setting and see what you get.

The ECT has nothing to do with the gauge, however if the engine is not warming up the cooler coolant temps could be affecting things.

How old is the T-stat?  It may need to be replaced.
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 09, 2008, 10:25:40 PM
The T-stat is only about 3 months old. How do I check my TPS?

Also, right now its about 60 degrees outside and I tried to start the car to move it. IT idles at about 1000 rpm for about 15 secs kinda rough and dies. I've tried three times. If I step on the gas, it dies immediatly. Maybe htis helps. lol
Title: 1987 turbo coupe high idle
Post by: Chuck W on August 09, 2008, 10:48:09 PM
Go back to the link on the NATO page I listed earlier.  There is a procedure for setting your TPS/idle adjustment.
Title: 1987 turbo coupe high idle
Post by: ipsd on August 10, 2008, 10:04:55 AM
this place will tell you how to test just about any sensor on a ford.
http://www.fordfuelinjection.com/
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 10, 2008, 03:12:25 PM
I adjusted the tps according to the NATO website. The problem is still here. I haven't checked codes again, but it still revs up to around 2000rpm after being driven a little and it warm.

Only sometimes this happens thought.
Title: 1987 turbo coupe high idle
Post by: Vbelisle on August 12, 2008, 08:20:18 PM
Quote from: jpc647;231458
I adjusted the tps according to the NATO website. The problem is still here. I haven't checked codes again, but it still revs up to around 2000rpm after being driven a little and it warm.

Only sometimes this happens thought.


Im also having the same problem with my 88 tc and i took mine to ford for a week because i know people that work there and they could not find the problem
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 12, 2008, 10:30:23 PM
The problems appears to occur most often is the RPM's are brought above 4000. Tonight I took on a modded maxima and it happened again. If i drive normally it doesn't appear to do it. At least this is the current prognosis. I also replaced the thermostate becuase it appeared maybe to be sticking open on occasion.
Title: 1987 turbo coupe high idle
Post by: softtouch on August 13, 2008, 05:13:41 PM
I added an extra spring to the throtttle linkage on my 3.8 because it didn't always return to idle.
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 13, 2008, 09:21:20 PM
did it return sometimes and not others? Did the extra spring solve your issue?
Title: 1987 turbo coupe high idle
Post by: softtouch on August 14, 2008, 02:12:02 AM
Quote from: jpc647;231857
did it return sometimes and not others? Did the extra spring solve your issue?

Yes and yes.
Title: 1987 turbo coupe high idle
Post by: jpc647 on August 14, 2008, 11:03:32 AM
Mine appears to be bottomed out. If i push down on it, it doesn't move. But i can try it. Thanks for the advice.