Ok, I need some help here. 1994 Camry, 5sfe. On startup engine revs to approx. 2200 rpm for about a minute then the idle begins to oscillate between 1700 and 2200 rpm about every second. After a few more minutes, it goes back to the high idle and back to the oscillation again. When engaging transmission in forward or reverse, the idle settles down to about 1100 to 1200 rpms (still a little high). Turning the AC off and on doesn't seem to affect it much. Most of my travel is interstate, so when I'm cruising along and coast, like getting on the exit ramp, the surging (oscillation) comes back while in gear. The surging goes away when I come to a stop or accelerate or just cruising, as long as there is steady pressure on the accelerator. There is also a jerk of sorts it seems in the transmission when I let off of the accelerator and when I reapply the accelerator when cruising. It seems to have lost it's cruising - coasting smoothness. Just in the past couple of days, it's starting to run a little rough (like is missing a little) while cruising and I think it's losing a little power because of it. This forum is such a great resource, I'm thankful for the smart Toyota advice. I'm going to check for vac leaks, clean the IAC & throttle body, change the fuel filter, plugs, rotor cap & button. . . any ideas are very much welcome.

 

I took my bd to the vet 3 days ago, because she wouldnt put on weight. The blood tests came back today. She has something wrong with the way she takes in protein and fat. I think it might be hereditary

 

OK, I did all I mentioned above, found a bad vac hose. The high rpm on start up went away but the surging continues. I need some suggestions... any ideas?

 

You state the surging goes away if there is pressure on the on the pedal, is this still true with the vac hose fix?

You might try moving the throttle pulley at the throttle body to simulate the pedal action and determine if this fixes the surge. Determine if the throttle pulley is being held fast against the throttle stop and not freely rotating slightly.

If missing check for a cracked coil.

A failing computer coolant sensor can cause all kinds of idle issues.

Clean the IAC valve.

The Autozone website should have info on checking various components for this model in the sites vehicle repair guide section.

 

--You state the surging goes away if there is pressure on the on the pedal, is this still true with the vac hose fix?

It's very similar to what was happening before the cleaning and tune up. It smoothes out when sitting at a stop, foot on the brake, in gear but idles at about 1300-1400 rpms. And yes, it also smoothes out with pressure on the pedal.

--You might try moving the throttle pulley at the throttle body to simulate the pedal action and determine if this fixes the surge. Determine if the throttle pulley is being held fast against the throttle stop and not freely rotating slightly.

No movement of the throttle pulley noted and yes simulating pedal pressure by turning the throttle pulley manually does make the surging go away.

--If missing check for a cracked coil.

Doesn't seem to miss in my current tests, the only time I have noticed any sort of miss is high speed driving. I haven't done this yet since my repairs this weekend.

--A failing computer coolant sensor can cause all kinds of idle issues.

I haven't checked this yet.

--Clean the IAC valve.

I disassembled and cleaned it thoroughly and also the throttle body and replaced gaskets. The bad vac hose came from the bottom of the IAC. One thing I stumbled upon was when I hold my finger over the hole that leads to the IAC at the bottom of the throttle body opening, the surging stopped and the idle leveled out at 2000 rpm

 

Is the foot on the brake required to the engine to stop surging or just for safety. If required check the power assist can, could be leaking. Disconnect the vacuum hose to the can and plug, then determine what happens.

 

I have similar issues with my 94 Camry except it has a rough idle at a stop and it is good every other time.

 

Clean IAC valve. Check for vacuum leaks.

 

I cleaned throttle body and IAC with throttle body cleaner, but I did not take the IAC off to clean it. I was not able to loosen the screws to get it off and I don't want to strip it. It doesn't look original. I did a visual check for vacuum leaks and was unable to find any. Any tips besides using carb cleaner to find them? Thank you

 

I have a 1994 Camry 4cyl w/68k miles - CA emissions with a lot of engine vibration at idle and sometimes in Neutral and Drive. I was driving along at 55 mph when the car died on me - it started right back up and hasn't done it since, but I am concerned. I have now changed coolant temp sensor, fuel filter, air filter, cleaned throttle body and IAC, changed 3 of the 4 motor mounts, thermostat, full tune up, PCV valve, did a test on EGR valve and it appears to be working, timing belt, water pump...could it be the timing is off...vacuum leak? if so I haven't been able to find the leak...my friend is going to run a compression test and run a different test to see if he can find a vacuum leak....could the O2 sensor cause this issue? I am open to suggestions....also the old plugs looked good when we took them out.....please help! Thank you! In His name....