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Simonhla
06-22-2008, 03:56 AM
So my car at idle has become my nemesis.......Before the rebuild I just did it was stalling on idle all the time. I discovered I had a cracked head and an engine with a lot of miles. During the rebuild we fitted a new idle air control valve because the old one was shot (it also has a new transmission). Once it was done it of course started stalling again on idle unless I kept the rpm's up.

Took it for a proper diagnostic and they told me my throttle position sensor was out.....ok.....so i replaced it. Got in the car yesterday and it died on ignition. Let it sit a few moments, same thing. Pulled the battery and took to autzone......"bad battery" comes back the test.....ok....bought a new battery and then went down and had the charging system tested. Everything is tip top, should be because the alternator is new too.

Drive the car home and it idles like a beast again. 80% of the time normal at about 900rpms, 10% of the time at about 1600 or 1800 rpm's and 10% of the time very very low (400-600rpms) and it nearly stalls out. It did in fact stall out on reverse. The diagnostic did not show me that i have any other problems.....so what the dickens is going on?

The only thing I know that is not stock on the car at this point is the timing which has been advanced 5 degrees to 15. Stock on these vehicles is 10. What should I be looking for to check that could be doing this? I am at my wits end......a month of rebuilding etc I just want my car back!!! arrgghh.

quark
06-22-2008, 02:03 PM
Have you consideret that your idle circuit in the ecu is dead? I know that the last place to look is in the ECU, but you have been everywhere else. If the maf gives a unstable signal, then that could be the problem also.

Simonhla
06-22-2008, 10:54 PM
No i hadn't considered that but i figured it would have come back on the diagnostic from the dealership.

Tomorrow I am checking MAF, MAP, vacuum lines, injectors and new TPS.

brak
06-23-2008, 05:59 AM
Vacuum leak is the first thing that comes to mind.

I had a similar problem a few years ago. idle would randomly drop to nearly nothing. I replaced all the vacuum lines, and the problem went away.

Simonhla
06-24-2008, 01:05 AM
Ok an update to this is that today it stalled whilst I was at about 20mph and accelerating................I am baffled. Any help??

Gidget
06-24-2008, 01:38 AM
are you getting enough fuel? check pump and injectors/filter.. that was/is my problem.

Galcobar
06-24-2008, 02:28 AM
Have you done a compression test?

Simonhla
06-24-2008, 06:27 AM
I am meeting my mechanic tomorrow to go over some things. I am definitely looking at the fuel thing. I think that could be it. As for a compression test I haven't done one no but he just rebuilt the engine for me so I am assuming that it is in tip top shape. Plus this was a problem before the rebuild too.

From everything I have read I am leaning towards a vacuum leak but he remains to be convinced.

METDeath
06-24-2008, 10:29 AM
I am meeting my mechanic tomorrow to go over some things. I am definitely looking at the fuel thing. I think that could be it. As for a compression test I haven't done one no but he just rebuilt the engine for me so I am assuming that it is in tip top shape. Plus this was a problem before the rebuild too.

From everything I have read I am leaning towards a vacuum leak but he remains to be convinced.

Ah... you made an assumption, know what that means?

Means you made an ass out of you and umption!

Personally though, I would do a check on all the vac lines, and compression test.

Simonhla
06-24-2008, 07:29 PM
Yes assumption is the mother of all F ups you are right. I just figured there were more likely places to start than a compression test. Gonna start with Vac lines today.

Galcobar
06-24-2008, 11:10 PM
When I had the lower end of the cylinder head rebuilt, I expected the same thing -- actually, so did my mechanic. Suprise, burning oil persisting a lot longer than the usual break-in time. Turned out he'd installed a bad set of piston rings, first time in 20 years he'd seen it he said.

That said, the fact it keeps stalling out at different engine speeds and loads makes me wonder about a wonky fuel supply as well.
http://www.celicatech.com/93rmsour/1993/93celica/fi/fuelpump.pdf

andy
06-24-2008, 11:42 PM
i bet you have one of your vsv's hooked up backwards.

Simonhla
06-26-2008, 12:45 AM
Ok so checked Vac lines and gaskets today and there is no leak that can be found.
No codes are coming back on the diagnostic.
The idle is still fluctuating and it will occasionally stall on acceleration.
It's back at the stealership because I am baffled.
It's been to 5 mechanics and no one knows what's wrong.

Simonhla
06-28-2008, 10:41 PM
So after convincing the dealership to give me another diagnostic forfree (What can I say I'm persuasive....the british accent helps!) we found the problem.

Despite the IACV being new and despite it not giving any codes back they found that the spring operated plunger inside was sticking, causing the many problems. They greased it and it is working well for the time being. I called A1 Auto from whom I ordered it and they were great, they have priority shipped me a replacement without any questions. I don't have to send back the faulty one until i've swapped it out which means the car stays on the road!!

Finally, the relief!

hemlocke
06-28-2008, 11:04 PM
Glad to hear it.

Rix86
06-29-2008, 12:19 AM
Get a factory IAC valve, and stop fucking around.
seriously, the first one failed, how many more do you want to replace?

Simonhla
06-29-2008, 12:34 AM
Well thanks for your input Rix. Unfortunately after rebuilding the engine, putting a new transmission in, new tires, new wheels and new a/c compressor I am dangerously low on cash. Hence my cheapness. This one was $115 and the OEM part os around twice that.

In a few months once I have digested the expensive I have just laid out, I will indeed "stop fucking around" and get the OEM part. For the time being though I am going to take the free replacement and hope it is not defective.

Rix86
06-29-2008, 01:14 AM
Well thanks for your input Rix. Unfortunately after rebuilding the engine, putting a new transmission in, new tires, new wheels and new a/c compressor I am dangerously low on cash. Hence my cheapness. This one was $115 and the OEM part os around twice that.

In a few months once I have digested the expensive I have just laid out, I will indeed "stop fucking around" and get the OEM part. For the time being though I am going to take the free replacement and hope it is not defective.
Understandable. :lolhittin
1st toyota parts might be a bit cheaper than you local dealership...

DeeCee
06-29-2008, 02:09 AM
idle contol screw on the throttle body maybe?