North American Turbocoupe Organization



How to fix a intermediate high idle.
Ritchie Thomas Offline
Junior Member
#1
I'm tackling problems one at a time on this car. I've got my flooding problem fixed now I want it to idle right. Ever since I have had it, it would idle between 1000 to 2000 rpm. It doesn't bounce but idles around 1000 when I start it up. After getting the car moving, when I push in the clutch, the idle is around 2000. If I stab the throttle, it goes back to 1000. I've changed the TPS and set the voltage at around .95 and also set be base idle (before setting the tps) by unplugging the ISC and setting the idle to 700. When I plug in the ISC it jumps back to 1000.00. Any ideas?
1987 Turbocoupe
Reply

TurboCoupe50 Offline
Posting Freak
#2
First be sure you have no vac leaks... You can try setting base idle lower, say 550-600 and/or lowering TPS voltage a little more(.85-.90)... If your meter isn't in good calibration(or possibly weak battery)the voltage may be higher than you think...

Problem could be as simple a pulling the battery cable for a few minutes, so it will start a new idle learn cycle...
1988 Turbo Coupe331 AOD

1972 Comet GT

1969 Fairlane Cobra 428CJ 4-Speed
Reply

Bill S. Offline
Senior Member
#3
idle air bypass could also be sticking open a cleaning couldn't hurt and its fairly easy Smile

Good luck!
'88 TC T5
'85 XR7 Roller
Mods on hold pending swap.
Stinger header & mBC on shelf
Reply

Kev Offline
Posting Freak
#4
My tbird has done this since I first bought it 8 years ago. I have tried all the fixes along with clean IAC, new IAC after that, new TPS set at .91 to .98 trying to find a happy place, new vacuum lines, vacuum gauge to make sure there are no leaks, new battery, new alternator, pb blaster in the throttle cable, new injectors, clean the fuel system, new fuel pump, and I'm sure there was other stuff that I tried that I have forgotten about, but I still get normal idle at startup, high idle after driving and then pushing in the clutch, and a normal idle after I stab the throttle quickly. I have just learned to live with it. So much so that if I drive another manual tranny vehicle besides my bird, I still stab the throttle quickly when coming to a stop with the clutch pushed in. Big Grin If you figure it out, I'd love to hear it!

Kev
Kev
1988 TC 5spd
Reply

Ritchie Thomas Offline
Junior Member
#5
Thats not what I wanted to hear but glad I'm not the only one.
1987 Turbocoupe
Reply

Matt S Offline
Posting Freak
#6
A new VAM erased all hanging high idle issues for me since 2004. However, just a couple days ago it did it again once. :confused: . I just could be time for a tune up and iac cleaning though, it's been about 15k miles.
Sold it Sad*
Reply

Pete D Offline
Administrator
#7
Check for crud build up around the throttle blade inside the throttle body. Clean the grounds for the engine and EEC
Pete Dunham


Reply

TurboE Offline
Posting Freak
#8
Exactly, clean out the throttle body. I know it sounds rediculous but it WORKS! Use carb cleaner and a green scotch pad and clean it up inside. I had the exact same issue, and that fixed it. I was glad too, because at the time i was in high school and it was a cheap fix, and i didn't have to use one foot on the clutch, and one foot on the brake and gas at the same time. I was told this by a ford mechanic i knew at the time.
-88 TC Black
5spd, Precision SC50 T3/T4, QH/SD Tune, Gillis, AFPR, 255FP, WB O2, K&N, Ported E6, 3" DP, ATR 2.5" Duals, 3:73 Rear, Konis, Eibachs, 18" Voxx Wheels, X Drilled Rotors.
-06 G35 Coupe Diamond Graphite
-97 Pathfinder
Reply

Ryan H Offline
Posting Freak
#9
My car has a new VAM, new IAC, new TPS, new ECT, and everything intake wise is super clean (read: pressure washed with detergent and dried before re-assembly). It has a 255HP fuel pump and Kirban set to stock pressure. Base idle is set correctly. My car has the same issue... I am with Kev, either just stab the throttle or blip the key off and on and the idle sinks back down to where it's supposed to go. I don't understand what these things are thinking sometimes, but oh well! Its a Turbo Coupe thing that I just live with. I'm on my 4th one now and they've all done it. Big Grin
'88 TC Smile Walbro 255HP, Stinger FMIC, PIT BOV, Pro 5.0, Kirban, RR cam, FRPP strut tower brace, T3
Reply

TurboCoupe50 Offline
Posting Freak
#10
You guys must be doing something wrong, I don't remember any of my 7-8 "driver" TCs having this issue(all but the now 5.0 TC were 5 speeds)... BUT I don't subscribe to the .9999v TPS setting either... I usually had mine around .80-.85v, no high idle and the ole ass-o-meter can't tell the difference... In the case of my 5.0 TC, in spite of what all the Mustang rags say, neither can the time slips from the dragstrip... I've run TPS voltage as low as .65v on it with no issue... It did seem lean when cold at .57v(low as my slotting would allow), but the EEC soon learned to compensate...

BTW my older daughter had a '88 5 speed TC for about four years and you know women(esp my daughter), would not lived with such a problem even if dad said it was normal...
1988 Turbo Coupe331 AOD

1972 Comet GT

1969 Fairlane Cobra 428CJ 4-Speed
Reply





Users browsing this thread:
1 Guest(s)



Theme © iAndrew 2018 - Software MyBB