Funky idle and turbo cooling question.

[LoveMySupra]

I finally got my 88 running. Idle after a cold start is fine but after a minute the idle starts to dance between 1400 and 1800. Repeatedly without missing a beat, back and forth..
Is this bad for the turbo cool down process of letting it idle before shutting off the car?

Thanks in advance,
Chris

 

[hvyman]

No it shouldnt be that bad on the turbo. The whole deal with that is oil temp. You want the oil to cool down and same with the turbo. If you can drive the car slowly at 1200 in gear for a mile or 2 or a min or 2 that would do the same thing as letting it sit and idle. In short you dont want to do a hard pull then pull over and shut the engine off. Also if you run synthetic its not really a problem but still a nice thing to do for your engine.

I would start by checking codes.
Might come up with 51 for the tps idle circuit.

Heres how you check. Even check if there is no light.
http://www.cygnusx1.net/Supra/TechTips/engine_error_codes.aspx

 

[jetjock]

^ Nicely done. They don't get much better than that...

 

[hvyman]

Why thank you sir.

 

[LoveMySupra]

On day one I had code 14 but it was seeming to start fine. Then after a few starts it was cranking a little extra longer. Now when I turn the key to start I hear two clicks from the passenger kick panel and the starter doesn't even engage. The last time it was running, I unplugged the isc and nothing changed so I figure at this point the isc is dead and the engine is making it idle this was as a default..
Is the check engine light on the 88 anything like the check engine light on the mkii supra where it will not blink if the tps is out of adjustment?
I was able to read code 14 from the check engine light.
I'll go check the codes again right now and search the forums for a no start condition. If my memory serves right, I have heard that gm engines with a bad crank sensor will not start for a few tries until it lands on the correct spot and it uses the signal from the cam sensor.. is the 7m anything like that?

Thanks so much for all the help!
Chris

 

[Nick M]

^ Nicely done. They don't get much better than that...

Who knew a stoner could be that focused, even if it is Yoda.

 

[jetjock]

True is that. But good he did...

 

[hvyman]

I dont even smoke anymore. For the most part.

14 Ignition Signal

Diagnosis
No "IGF" signal to ECU "A" times in succession.
A = 6-8 (7M-GE)
A= 3 (7M-GTE)
Trouble Area
Igniter and ignition coil circuit
Igniter and ignition coil
ECU

Id look at the battery as well if the starter is not working.

 

[LoveMySupra]

I had unplugged the ecu clearing the 14 code, not that that is how I went about clearing the codes but I was just checking if it was the ecu... Checked the codes and they are clear.
Checked my battery fluid and ALL cells were half filled. A little top-off, a fast charge and now a slow charge is in progress. Checked to see if it would start and it does. I didn't let it idle long enough to show me if it is still acting all buggy with the idle.
Again, THANKS FOR ALL THE ASSISTANCE!
Much appreciated!

 

[hvyman]

Its generally easier and safer to just pull the efi fuse for 30 sec+. If you really want to take a wrench to do it pull the battery ground off for 30 sec+. Always take the ground off first then take the postive off. Postive goes on first then the ground. But taking off the battery ground will make you lose your radio presets and then the ecu has to relearn idle.

 

[LoveMySupra]

So the no start problem is the battery. I swsapped batteries with my mkii and viola, no starting issues yet. Idle is still bouncing. I just think my mkiii has a heart beat. LoL

 

[LoveMySupra]

Its generally easier and safer to just pull the efi fuse for 30 sec+. If you really want to take a wrench to do it pull the battery ground off for 30 sec+. Always take the ground off first then take the postive off. Postive goes on first then the ground. But taking off the battery ground will make you lose your radio presets and then the ecu has to relearn idle.

I usually pull the ground from the battery to clear codes. Pulling the efi fuse is new to me and
that's really quick and easy. I have another ecu and was seeing if there was a problem within the ecu pertaining to code 14.
I've driven it now for about 50 miles and there are no codes.