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Discussion Starter · #1 ·
Hello. I have a very nice 1989 4Runner 4X4 DLX with 22RE engine and 5spd trans. I am third owner and this vehicle has been VERY WELL maintained and garage kept most of its life. It has 204K miles.

Here is my situation - the truck runs like a top, but it idles rough after it warms up. When I first start it, it idles up and idles smooth, I assume because the choke is engaged. But once it warms up, the idle RPMs slow down and the idle becomes very rough, at least to me it seems to be rough. The gear shifter shakes somewhat and it appears as if the engine is going to die any second, but it has yet to do so. I have never seen a motor idle rough and appear to be dying, only to run like a top when you give it gas.

Here is what has been done maintenance wise since the vehicle was purchased.

150k...changed heater core, timing chain and clutch
166k...plugs, plug wires, shocks
169k...clutch master cylinder, belts, hoses and thermostat, front crank seal, flush rad, valve cover gasket & cam seal, vacuum lines & changed brake fluid, sending unit for fuel guage
173k...rear brakes
192k...steering stabilizer
195k....front brake pads
198k....alternator
201k....water pump


I realize alof of the past maintenance has nothing to do with the idle but just listed it anyway.

My question is what further maintenance would you suggest me do in an attempt to clean up the idle?

Any ideas/suggestions will be very much appreciated.

v/r
AndyTN
 

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There's no choke on EFI motors - just a cold start injector, which is probably not causing your issue since it only fires for a few seconds at startup.

Your plugs should be replaced every 30k miles or 3 years, so if not changed since 166k, those need replacing. Best plugs for the motor are the Denso W16EXR-U, available from most Autozones, or rockauto.com, or get the Toyota ones from 1sttoyotaparts.com - those are Densos. Gap to .032", a teeny bit over spec.

I don't see distributor cap and rotor on there - they should be replaced when you change the plugs.

I also don't see oxygen sensor in the list. Those need to be changed at least every 90k miles. Engine won't run right when that's not sending accurate signals to the computer.

Rough idle on 22re often caused by dirty throttle body. See these threads:
http://www.toyotanation.com/forum/showthread.php?t=289679
http://www.toyotanation.com/forum/showthread.php?t=288993

Another common cause of rough idle is failure of the TPS - throttle position sensor. Check the factory manual for instructions on checking - especially make sure IDL & E2 have continuity (less than 2.3k ohms) when throttle is closed (idle position). If you don't have a manual, google 1993 toyota pickup service manual. If IDL & E2 don't have continuity, that will mess up a number of functions of the computer and will cause poor idle as too much fuel is being injected. Try to adjust the position of the sensor to see if you can get the IDL-E2 contacts to close; otherwise you'll have to replace it.

There's a typo in the 93 manual's VTA - E2 specs. With throttle closed, should be .47k to .81k ohms, not .47k - 8.1k ohms as listed in that year manual. Resistance between VTA & E2 should change smoothly as the throttle is slowly opened and closed, with no spikes or dropouts.

Other service items listed in second link above.

Probably your valves were adjusted when your timing chain was replaced, but if not, that should be done. There's some info on that referenced in the second link above.

Good luck. Let us know if you have other questions, and please let us know how you make out.
 

· TN Member
1986 Toyota Camry
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269 Posts
ok its probably your idle set screw...the same thing happened to me with my 22re about three months ago...

just adjust it and you should be fine...
 

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Discussion Starter · #6 ·
Update with few more questions

Update on what I did and what the truck is still doing/not doing. First off, thanks for all of your help thus far. I am a shade tree mechanic at best so bear with me.

Per your suggestions, I replaced cap, rotor, plugs (gapped .032), plug wires and O2 sensor, all OEM from Toyota.

The idle seems to have improved somewhat. Overall, the motor sounds good idle wise, but the slight miss that is sporadic can be heard if you listen to the exhaust pipe. Below is the unique situation which leads to the roughest idle where it appears the truck is about to die:

Last night I drove the truck to my mom's house, approx 5 miles one direction, the truck runs like a champ all the way there and all. I park it for thirty minutes while I visit with her. When I leave I crank the truck to leave. I do not pump the gas pedal, I just turn the key over and crank it and it starts but boy is the idle rough. I let it idle till it sounds like it is just about to die (prob 30-45 sec), then I pump the gas pedal and it idles up and I drive it home and it runs like a champ. I really think had I not pumped the gas pedal, the truck would have died on me. But I know it would have started again and drove home like a champ like it always does. This behavior bedazzles me to say the least.

Any ideas as what is still causing this rough idle, particularly "at start up after it has been driven and sitting for short period of time."

I tried to describe exactly what I am experiencing. If I missed the mark or you have add'l questions, shoot from the hip. :)

Any ideas/suggestions will be very much appreciated.
 

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Did you check the tps?
 

· Registered
89 pickup
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Do the 22RE's have a base idle you can set? (air valve unplugged) or do you adjust with everything hooked up? Sounds like you might maybe possibly have a low idle? Anyone?
 

· The Mada
1991 Toyota Pickup
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130 Posts
I am having the same problem. Went to the store and shook like an earthquake when I was about to leave the parking lot. Started to die when I was at a light, my lights dimmed truck made high pitched whistle that it always makes when its about to stall/die.
 

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Sorry for the old-thread-resurection (I'm new here)

So what's the story here? This is happening to me as well in my 94 P/U 2wd 22re (141k).

I replaced the plugs, wires, cap and rotor and tossed in a can of seafoam. Haven't checked the TPS.
 

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Read number 2s commentary on how to test your Throttle Position Sensor. As you advance the throttle your meter should show a smooth transition in resistance through the whole range of the throttle. This is easier to see on a volt ohmmeter with a needle instead of a digital meter. Because your gas pedal typically sits at idle or the same spot when going steadily down the highway, these spots on the sensor resistor wear the carbon away. This breaks the electrical connection to your engine computer, causing the ruff idle.
 

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Read number 2s commentary on how to test your Throttle Position Sensor. As you advance the throttle your meter should show a smooth transition in resistance through the whole range of the throttle. This is easier to see on a volt ohmmeter with a needle instead of a digital meter. Because your gas pedal typically sits at idle or the same spot when going steadily down the highway, these spots on the sensor resistor wear the carbon away. This breaks the electrical connection to your engine computer, causing the ruff idle.
This will be seen on the meter by the smooth transition being interrupted by erratic behavior, those are the bad spots. If bad, take the sensor apart and you will see the worn out spots.
 
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