1992 Corolla w/ rough idle - Toyota Nation Forum : Toyota Car and Truck Forums

eggadeath · 10-29-2007, 12:08 PM

I bought this car off of a grandmther about 2 months ago. It only has 85k miles on it. It also runs perfect until I pull up to a light. After stopping at the light it runs fine for a few seconds and then starts to hesitate and wants to stall. If the car is not warmed up it will stall. I've also noticed a strong smell of gas coming from the car. I can really smell it when i go into the garage in the morning. Also seems to getting poor mileage.

I've replaced air filter, plugs, plug wires, dist. cap and button, also ran codes and no problems arose.

Any suggestions would be greatly appreciated.

tashirosgt · 10-30-2007, 10:04 AM

I don't recognize those symptoms as defining a particular source of trouble. So, my suggestion is that you start with the simplest checks. Is the sensor that goes into the side of the box that holds the air filter plugged in? Is the PCV valve clogged?

If you can make the car run rough when it idles, use a timing light and check that you are getting spark on each wire when this happens. You can hold a length of pipe or stick against each injector and listen to see that it is firing. Also do a compression test. These would be checks for something that is causing combustion to fail.

***REN69*** · 10-30-2007, 11:14 AM

The fact that it "smells like gas" didn't trigger any flags that this could be fuel system related? check your fuel filter as it could be clogged, it could also be a failing fuel pump.

90 GP · 10-30-2007, 06:34 PM

Check for fuel leaks in the gas lines under the hood and back to the gas tank.

Donald · 10-30-2007, 06:41 PM

Check for wet spots under the injectors. Those "O" rings and grommets get real brittle after a while and allow fuel leaks at the top of the injector and air leaks at the bottom.
Had the same problem with my '92.

eggadeath · 10-31-2007, 11:26 PM

I forgot to mention that I did replace the pcv valve. And yes of course I think its fuel system related. But was seeking a little advise before I tried every solution under the sun. Ill try the fuel filter. Ill do all the others as well and see what happens.
Thanks again.

Donald · 11-01-2007, 04:10 PM

In a case where you are smelling fuel, I would look for a leak first.

eggadeath · 11-01-2007, 05:12 PM

I checked the injectors and they are functioning. I checked the plug wires with a timing gun and they are firing. There is no gas around the O-rings and no leaks visible when car is running or stopped.

Over all the car runs great except at stops. Seems to be starved for fuel when in drive at stop lights, symptom lightens up when I put the car in neutral. The over all problem gets better as the car warms up.

jmaz87 · 11-22-2007, 05:36 PM

that sounds more like the IAC valve on the intake just before the butterfly-valve there are two parts the top has a screw to adjust the idle you might want to bring it up some and the lower is supposed to have a diaphram that opens and closes, mine was frozen open so i filled it with thermo-silicon and put it back together(i only need the screw now) and it runs fine.
stuck open i was idling at 2000 so it is stuck shut it would stall!

stagnot · 06-25-2008, 10:58 AM

did you ever find out what the problem was? i also have a problem like yours.

jmaz87 · 06-25-2008, 11:19 AM

you might smell gas because your gas cap is not sealing properly and I still think it's the toyota equivelent of the IAC valve in american cars...

i had a similar problem you can either get another Throttle body from a junker or you can take it off and unbolt the valve ass. and (don't recommend) i filled the sucker with RTV and that way your idle-adjustment screw and your timing are the only things affecting your idle... mine has not failed in a year since.