Won't idle, won't rev past 2700 rpms

eboutin88

New Member
Jan 18, 2009
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I am new to the supra, I have mainly tinkered with V8's in my nova. Saw one of these supras and wanted to fix one up. I drove over to Niagara falls, NY from vermont to pick a 87 supra. The supra had a manual boost controller for a mod and that was it. Boost turned up high I thought for a stock fuel and air system. Boosting up to about 18 lbs which was at 4000 rpms and would I assume fuel cut. I drove it home babying the car because I did not think it would be safe to try and hammer on yet. I got home parked the car, and tried to start the car and it would not idle. I took the afm off my other car that ran fine until the head gasket blew. After installing that afm the car would start but would cut out in nuetral at 2700 rpms. Vehicle is responsive until rev goes beyond 2700 rpms. Also the idling is rough. I thought maybe it would be the tps and I changed that, calibrated it with a multimeter and it still wont idle. I then replaced the isc and still wont idle. At the same time this issue occured I started to hear a ticking which sounds like a valve. Not sure motor only has 1500 miles on it. I am stumped, check engine light is not on, and I cant figure it out. Any help would be greatly appreciated.
 

eboutin88

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Jan 18, 2009
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is there a way to check afm with multimeter

I think the tps is ok, replaced and checked with multimeter but will check again might not be calibrated right
 

eboutin88

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Jan 18, 2009
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just talked to a buddy of mine who works as a service manager. He recommended that I should check the timing, he thought that maybe the timing belt skipped and caused the timing to be off. Sounds look it would make sense with the ticking that was all of a sudden, and rough running.
 

eboutin88

New Member
Jan 18, 2009
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just talked to a buddy of mine who works as a service manager. He recommended that I should check the timing, he thought that maybe the timing belt skipped and caused the timing to be off. Sounds look it would make sense with the ticking that was all of a sudden, and rough running.
 

thevork

ShoarmaTeam Member
why would you fiddle with the afm if you don't know whether that is the problem or not?
First set the TPS right. Then put the original AFM back in. your car still won't idle even with the other AFM so probably that is not your problem.

My best guess is that you have a huge vacuum leak and that your trip home made the leak big enough to cause you trouble.

I'd put the original parts back (minus the tps maybe), set the TPS and check for vacuum leaks.
After doing this, you can try unhooking the ICSV (it's on the intake mani, near the throttle body) and see if it changes anything.


Checking timing is not an option when your car won't idle, not without visual inspection.
 

kracin

Sleeper
Apr 1, 2007
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aiea hawaii
so you boosted it a couple times before you drove it back to your place? you may have loosened up an intercooler pipe.

but other than a possible intercooler pipe blowing off, your afm sounds like the culprit.


and you would "fiddle" with the afm first because a clear symptom of a bad afm, or an afm thats causing trouble is not revving over 2500ish rpm. tps wont cause that unless the damn thing just fell off all together.
 

thevork

ShoarmaTeam Member
kracin;1390189 said:
and you would "fiddle" with the afm first because a clear symptom of a bad afm, or an afm thats causing trouble is not revving over 2500ish rpm. tps wont cause that unless the damn thing just fell off all together.

That is correct however there is no sign that changing the afm helped in any way.
Could he also rev to 2500 on the old afm? It's not clear that he tested that.

Even more, if he didn't test that it's very possible that he swapped out a good afm for a bad one causing the 2500rpm cutoff. Who knows ? only the TS can tell. ;)
Diagnosing a car by just throwing parts at it is never a good way to start fault finding and may cover up other culprits.