Chihuahuamaster

Greetings forum members. My 91 pickup w/ 22re keeps dying at idle only after reaching normal operating temperature.

I searched the forum and someone suggested cleaning the EGR with sensor safe carburetor cleaner.

I took off EGR valve and sprayed it down good with cleaner also removing some carbon that was built up inside the metal tube on the bottom of EGR where the vaccuum line connects. It had quite a bit of carbon. I did not have a vacuum pump to activate EGR and clean simultaneously.

Unfortunately, I am still having the same dying at idle problem.

Does anyone have any suggestions what might be causing this? The pickup has 365,000 original miles.

Co_94_PU

iTrader: (-1)

EGR valve should not be open at idle, the quickest way to find out if there is an EGR system problem is to temporarily block it off. cut a tin can up to place between the valve flange and plenum port.

If that lets it sustain idle then you can debug the system. Other wise your idle screw is probably in to far.

For the EGR, check the vsv (if your model year has one, it'll be listed on the vacuum map under the hood), or the modulator, and that the EGR valve fully closes.

Chihuahuamaster

Is the plenum port the area where the EGR bolts up top to the throttle body?

Co_94_PU

iTrader: (-1)

Yes..

sorry got overly specific. "The rear of the upper intake" probably makes more sense for you?

Throttle body, is the removable bit at the front that houses the throttle plate (with the springs and stuff on the side) and not part of the upper intake.

The plenum, is the tube between the throttle body mount and the upper intake runners.

Runners, are the individual tubes leading to each cylinder.

Google define: plenum
"an enclosed chamber where a treated substance collects for distribution."

Chihuahuamaster

Could this problem be related to a bad engine coolant temperature sensor?

Chihuahuamaster

Again, has anyone had any experience with a bad coolant temp senor and the related symptoms? Thanks.

yota tay

I'm having this exact issue but mine isn't dying. I made sure the tps is in specs, changed ect, O2 sensor, plugs, wires, cap, grounds????? Im thinking maybe the dashpot needs adjustment? Also cleaned TB and valve underneath and checked vacuum leaks and verified proper operation of afm and egr. All above checked out fine. Maybe my exhaust leak is causing my O2 sensor to go wack?

yota tay

Does the truck drive or does it die as soon as it warms up? Remove and soak the idle air control valve and throttle body in carb cleaner. Check and make sure all grounds are present, clean and tight. Check O2, ect, tps, afm with a electric meter for resistance per fsm. Make sure your coolant is full and last but not least check the timing. Yours may have clogged or bad injectors.

Chihuahuamaster

The pickup truck still drives. It only dies when I pull up to a stop sign and don't have my foot on the accelerator.

Terrys87

iTrader: (1)

The only sensors I have ever seen go bad is the Throttle Position, O2, and Cold Start Sensors. The TPS can get a good cleaning and still pass test and fail. It is usually just worn out. I replace it if I suspect it is bad. The Dash Pot can be bad as well but really is not a sensor.

From my experience, I clean the Intake System including the EGR. I have never had a bad EGR but it is so dirty that it needs a good cleaning. I just use a long vacuum hose and am able to do test on it to see if the valve is operating with just the vacuum of my lungs. Then I clean all of the other sensors with a brass tooth brush and make sure all vacuum lines are clear. Pages 1 and 2 on my 85 truck build in my signature shows quite a bit on the sensors.

After a good testing and cleaning of the sensors, I replace the spark plug wires from ebay with Denso. I get my plugs, cap, and rotor from Toyota. A fuel filter and air filter from my local part store and then I do a complete tune up by the manual including the valves. Haynes has a good procedure if you do not have a Factory Service Manual.

After all of the above is done, then I start seeing if I have any other issues. Usually the above will solve 90% of any problems I may have. You will be surprised at how old some of the consumable parts that I have listed are and can cause several issues. I have seen it many times.

The AFM has never thrown a code on my unless it is not hooked up and I have had some bad AFMs. You will need to get a multimeter and follow test in the Haynes Manual to see if it will pass. Make sure the flapper moves freely.

Burp the system by raising the front end as high as possible and let air out of the cooling system with the radiator cap off and let the thermostat cycle 4 or 5 times.

Currently l would suspect your Dash Pot.

yota tay

​​​​​Either your dashpot, throttle body or injectors.