1992 Celica 2.2 idle problem - Toyota Nation Forum : Toyota Car and Truck Forums

Nova_Guy · 09-14-2008, 09:10 AM

My 1992 Toyota, Celica had developed a really weird idle surge. The idle surges between 500 to 750 rpm. The surge goes away with the AC on and it idles steady at 900 Rpm. It also has a slight off idle bog that may just be another symptom of the weird idle.
I did the diagnostic test today and it doesn't flash any codes. I pulled the EGR valve off and cleaned the gunk out of it and it didn't make any difference. I tried to check the timing and it idles so bad the timing bounces 7-10 degrees with the surge. When I did the jumper to check the timing it would kill the engine. The plugs and wires are new with in a couple thousand miles. It runs fine above idle and pulls to redline easily in the lower gears.
Yesterday when I was messing with it I had the car running with the air boot from the air cleaner to throttle body off. I sprayed carb cleaner into throttle body and it seems to clear up a little bit. Then it went back to surging again.
I tried to pull the TPS off yesterday and of course the bottom screw stripped out. Now I will have to pull the throttle body off to get the screw out.
I wish it would throw a code so I could have it give me a clue.

The Haynes manual I have is worthless as far as troubleshooting the issues I'm having. Anyone have any ideas, besides driving it off a cliff?

92-gt · 09-21-2008, 02:55 PM

check your idle air control valve

streetrider · 09-21-2008, 03:01 PM

I've had a car do the same thing with a intake gasket leak.

and yes haynes is worthless. Chilton is better and oem toyota manuals are the best.

Nova_Guy · 09-21-2008, 05:32 PM

I have tried about everything to fix this car. I went to a local salvage yard and bought a used throttle body, idle air control valve, absolute manifold pressure sensor, EGR valve vacuum modulator, water temp sender, fuel pressure regulator, AC amplifier & idle up VSV, the VSV valve for the EGR valve, the BVSV for evap system. None of the stuff I replaced made any difference in the way the car runs. I figured even if the part was bad at least it would make a change in my idle quality and I could narrow the problem down. A new idle air control valve was 185.00 at Advance Auto Parts. I only spent $44.00 on my used parts.
I have sprayed carb cleaner on and over every hose under the hood chased down every line to make sure it was on correct place.

I found this manual online and have tried T/S some of the parts I bought to make sure they worked or that my old part was working. I have a Haynes manual and on I bought off ebay and this one. None have pointed me towards a fix. My next step is a factory manual or a dealer repair.
http://www.onlinefreeebooks.net/automotive-machinery-power-equipment-ebooks/toyota/toyota-celica-repair-manual-pdf.html

The crazy part is on the back of the intake there is a vacuum splitter. It screws into the intake. One port goes to the fuel regulator the other goes to the absolute manifold pressure sensor. If the line going to the pressure regulator is pulled off the car runs great. If you put the line to the other side of the intake to another port the car still runs fine. As long as the port beside the absolute manifold pressure sensor is leaking it runs fine. I moved the absolute manifold pressure sensor to another port on the intake and it goes back to the initial problem of surging. The car holds right at 20lbs of vacuum idling and runs great as long as the port is a vacuum leak.
If I use my vacuum pump and put about 10 lbs of vacuum on the absolute manifold pressure sensor the car runs good. The intake has almost 20lbs of steady vacuum. That tells me there isn't and intake leak. I think it has to do with the absolute manifold pressure sensor. I replaced it and it didn't make any difference.

***new echo owner*** · 09-21-2008, 06:39 PM

What is your fuel pressure? It sounds like you are running lean, since you were able to make it run better with 10" of vacuum, which simulate an acceleration condition.

N.E.O.

Nova_Guy · 09-21-2008, 07:21 PM

I'll check it and post it in a couple of days. I'm going to be busy for the next few nights after work.

Nova_Guy · 10-23-2008, 06:19 PM

Well I finally figured out what was wrong with my car. The weather has turned colder and the heat worked but not real well. I was thinking about this and I remembered the idle air control valve has water running through it. I think the water temp was to cold to make the valve thermostatic spring work right on the idle air control valve. The temp gauge is just at the halfway mark on the gauge now. Before it was at the 2-3 mark point before.
After I replaced the t-stat the car runs at the center of the gauge and the heat air is much hotter. It was the original t-stat in the car. That fixed the idle to the point it would idle with the vacuum leak plugged. Then I unplugged the absolute manifold pressure sensor and swapped it with a another one I bought. I had suspected it was bad from the beginning of this mess. The car idled perfect and runs down the road like it did before this whole mess started.
It took a while but I learned a lot about how the EFI works on the car and what the sensors do what.