Hskr8

Hi, new to this forum, and recently bought a 94 toyota pickup 4WD with a 22-RE EFI engine with only 60K miles on it.

I changed the oil when I bought it, and have been getting good gas mileage (17-18 mpg, mixed) but I am having a wierd idle problem when the engine is warm.

On a cold start, the idle is higher, as it should be, so no problem there. Throttle response is good, power is good. After the engine is warmed up, and usually notice this after I have driven somewhere, stop at a store, come back out and start up again, the idle seems a bit rough, and the rpm's are too low. I upped the idle very slightly, and that hasn't helped. The engine hasn't stalled on me, but sounds as if it is going to. The stick shifter will vibrate pretty healthily, but not too viloent, just more than it should.

From what I have been researching, this could be the IAC? but not sure how to clean it, test it, or even where it's located. My Haynes manual is not showing me much of anything.

One other thing, which may be related, or may not be, is my temperature guage seems to only go up slightly. It does start out at the bottom on a cold start, and it does rise as the engine warms, but only reaches maybe 1/8 of the scale of the guage. I turned the heater on max and the guage did rise to almost 1/4, so not sure if it is a thermostat problem or not. I did spend some time checking the heat of the upper radiator hose from a cold start, and it remained cool from initial startup and didn't get warm until about 5 minutes of the engine idling, so I think the thermostat is closed and opens when warm like it should.

Again, this could be unrelated to the warm idling issue, but if anyone has any insight as to what is going on or what I should check, it would be appreciated.

Thanks in advance,
Hskr8

seaflea

Bump!
Hopefully some one will chime in with a good answer. I have the same problems on mine. I have converted to a 92 t-body and upper plennum, so I wonder if it has something to do with the t-body.

Sounds like youre cooling issue is not an issue at all. Except that it gets warmer if turn on the heater? thats odd I would think it would get cooler.

Oh yeah, Welcome to the board

Hskr8

Thanks seaflea!

yes, it seems counter intuitive that by turning on the heat, the temp guage would go up... at the time, I was checking to see that the air was hot, which it was, and just figured that the guage wasn't accurate, as I do think the thermostat is working and not stuck in the open position.

Really there are no other symptoms, as the heater works great, as does the AC... so I'm just thinking the guage isn't calibrated right or something, as nothing else leads me to believe there is a problem.

The warm idle issue is still a problem, and not quite sure what to do to fix it. Turning up the idle might prevent a stall, (which I haven't had), but isn't really a fix either...

mike_d

i'll answer the easy problem first: on the 22re, the heater core return is just before the thermostat, so when you turn on your heater it outputs cold water on the thermostat, so the thermostat stays cold and the engine heats up. check out roger brown's website (www.4crawler.com) for an easy fix. it's in the cheap tricks section.

now on the the rough idle. my uneducated guess is that the load from the fan is causing the rough idle. i know that on my 22re, i have a perfectly smooth idle at 750rpm when the engine is warm, but not so hot that the fan is engaged. when sitting in traffic and the engine starts to heat up and the fan engages, the idle goes down a bit and it's rough.

since you're engine temp is never getting up, then you may have a problem where the fan clutch is enganged all the time, so it's keeping the engine too cold and adding extra drag causing the rough idle. a quick test, when the engine is cold, try to turn the fan by hand, it should spin with little resistance. now warm the engine up to operating temp then shut it off and try to spin the fan by hand. there should now be a lot of resistance.

check out this discussion on the fan: https://www.yotatech.com/forums/f2/fan-always-38411/

Hskr8

Ok, cold engine (80 degree day) I can try to spin the main fan, and it's easy to spin, but offers some resistance... I spin it as hard as I can, and it goes maybe an inch past the point where my finger leaves it. Again, it won't freewheel, but it's easy to turn. Also made sure I was turning it in the driection that the fan blades would go to blow air over the engine... from left to right as you are standing in front leaning over the hood.

Started her up, let her warm up...

for S&G, I pulled the hose off the most forward valve cover nipple... I don't think this is the PCV, as there is no unit underneath. Definate hissing sound when off, plugged the tube with my finger, no change in idle, (which dropped only slightly when I unplugged it) Plugged the nipple on top of valve cover, engine acted like it was going to die, but did not... so there is definately vacum at this forward nipple. Hooked that hose back up.

Unplugged rear nipple on top of the valve cover, and I see a silver peice underneath, so thinking this is the PVC valve... as soon as the hose comes off, the moter dies.

I put it back on and start back up.

idling a little rough, but not as much as usual.

I wait a few minutes, then shut it down.

Try to spin the fan, expecting there to be much more resistence, and it is actually less resistance.

It alsmost frewheels

I spin it as hard as I can, left to right, leaning over it, and when my finger leaves the blade, the fan travels roughly 3/4 of a turn... far more than the inch or so earlier.

seems counter intuitive to what you posted Mike, but just trying to be as detailed as I can.

I only removed those hoses to check for any effect, as well as to check for vacum issues.

mike_d

i checked on my way out of work today, just to double check against what you said. the fan was stiff to move when the engine was cold. pretty much like you described. then when i got home, i tried it again, the fan was much harder to move, it pretty much stopped as soon as i let go of it. maybe some more people can test theirs and post their experience.

Hskr8

ok we have the exact opposite issue then... same fan resistance when cold, but different when warm.... not sure what the fix is, but at least we have something to go on....

hey, what is this fan clutch thing? is there a way I can test mine outside of what we have already done?

mike_d

the fan clutch is the part that controls if the fan is engaged or not. it's the cylinder-like object between the fan and the water pump. the metal is formed like a heat sink on the outside so that it can adjust to the engine temperature quickly. i don't know of any other way to check it. the only thing that my factory service manual says about the fan clutch is to check it for "damage and silicone oil leakage" they don't say how to check it or anything like that.

Hskr8

ok, did some more testing this morning... fan blade spins with resistance, I get about an inch of after spin... on cold start, the fan blows mucho amounts of air for about a minute, maybe less, then settles in to normal speed.

this time I let the truck idle for over 20 minutes... checked that the upper radiator hose got hot when thermostat opened. Turned on the heat, only slight temp rise.. no change in fan speed. Turned on A/C, idle went up, fan speed went up, temp guage dropped slightly.

shut it off, tried to spin fan, and this time it's more resistant, but very similar to cold. Instead of an inch of movement, I get about half an inch, so maybe the fan clutch is flakey or something. yesterday I thought I had warmed it up enough, (10 min idling) and it spun allot more freely.

My understanding is it should move freely when cold, and resistant when hot...

from yesterday to today, the only difference is I let it idle allot longer, and it's not as hot outside this morning... maybe 65 degrees outside.

the only constant, is when cold, it doesn't seem to spin freely, and the fan travels only an inch or so after I spin it.

was a little concerned that the fan would turn on after I shut it off, (don't want to lose any fingers) but so far, I haven't noticed that the fan has ever turned on after shutting off the motor.

It was definately hot under the hood, so I'm wondering if my guage is just goofy, or if there is a temp sensor that needs replacing... again, the guage works, meaning it starts out low and climbs, so it's not a fuse or anything, but I'm leaning more toward something in the temp sensor.

paranoidandroid

My corolla has the same problem. temp always at the lower 1/8th of the meter. Was told it was a faulty sensor, but I'm too lazy/cheap to replace

PirateFins

Your fan sounds just like mine. You need to get the silicone fluid, and gasket from the dealer so you can r&r the clutch assembly. When cold the fan should turn free (not free wheel, but have little resistance), when hot it should be hard to spin. Don't worry about choping fingers off with the motor off, it is a belt driven fan, motor off = no spin. The way it works is when @ normal operating temp the fan spins at low rpm's, when extra cooling is needed because the motor is heating up the silicone fluid expands and engages the clutch and spins the fan @ full pulley rpm's.

Ok the fan is out of the way. Now to your ruff idle. Test out your cold start injector system. It sounds like it is open or leaking, and when you are @ normal operating temp, it is causing a rich condition.

SlimJim248@earthlink

22re's don't run warm. I wouldn't even worry about your thermostat. My 89 has the original thermo in at 120k and the temp guage stayed cool the day I pulled it off the dealers lot in 89. However, My other 22re has the same idle issue it sounds you do. I have tested the afm and tps and still no luck. Anyone familiar with the rough idle issue. Mine bounces back and forth slightly when the rpms are anything below 1000.

dragon564

Gents,


I think that the part you are calling a FAN CLUTCH is not a true clutch that can engage and disengage allowing a "free spin" It is more of a shock absorber and viberation dampener than a clutch.....objects in motion tend to stay in motion...blah blah blah...but the air the fan is moving can not slow down as quickly as the engine can slow the fan speeding up is the same....so that little metal box is there....the few that I have taken apart have a thick oil (almost gear type 70-90 weights) and a flat coil spring....and all bolted together as one piece....no means to allow for free spin....the system really is not the best that could be done....I took the whole thing off and put on a electric fan with built in t stat....it keeps the enginge much cooler as fan speed is no longer slaved to engine speed....which is not a good set up for heavy traffic...Japan has plenty of HEAVY TRAFFIC...puts SoCal rush hour to shame......some times you are happy if you can avg 10mph....it has taken me over 4 hours to drive less than 60 miles and that happens all the time over here......plus you have some pep from the line as your engine is not trying to turn that system....that may well be a SEEMS LIKE but I do seems to feel the difference.

YotaJunky

Seaflea,

Did you ever figure out what the problem was with rough idling after a warm restart? I'm racking out my brains trying to resolve it.

Troy

Hskr8

I have done everything, the last things I can see are additional TBS adjustments... I made some, and only seems to be worse now or O2 sensors, which are expensive as all get out.

Even with the problem, I still get about 20 mpg 60/40 Highway/City

YotaJunky

Thanks for the reply, especially since it's been more than a year from the original posting date. Yotech is a godsend for me, and it's helped me out a lot.

Here's what I've done so far:

1. reset TPS (this cleared the only code that came up).
2. new rotor, cap, plugs, wires, fuel filter, cat converter, PCV, air filter.
3. cleaned the TB, idle adjustment screw inlet/channel.
4. checked the idle air valve, temperature sensor, cold fuel injector timer switch, ignition coil.
5. checked for vacuum leaks in air intake and hoses, egr for proper operation.
6. checked for loose wiring.
7. dealership checked out the fuel pressure and ruled out any fuel issues.
8. pulled plenum and looked for blockage, cracks etc...

I'm looking into:

1. AFM (air flow meter)
2. O2 sensor

This is such a mystery to me. I'm just throwing money at this problem, but like you, I'm still getting about 18 to 19 miles to the gallon.

Troy

seaflea

I did. I my case it was a dirty O2 sensor. I pulled it out and cleaned it up and have been fine since. I have a feeling that I will havet o buy one soon though since I am on the original one.....

YotaJunky

My situation is similar to Hskr8's. During cold starts or after leaving the engine for a few hours, it starts up fine with minimal roughness at idle. If I warm it up to operating temperature, turn it off, and then try to do a warm restart after 15 to 60 minutes, it sometimes idles so roughly (feels more like loping and bucking) that it has stalled out. But if I then give it a little gas, the idle smooths out enough that it won't stall out. The engine always sounds a little "lumpy", but I'm more concerned about the rough idle after warm restarts.

Seaflea, did this sound like your problem before cleaning the O2 sensor? BTW, did you have any problems removing your O2 sensor? Mine is frozen onto the front pipe from rust. Also, how and what did you use to clean the O2 sensor?

Troy

seaflea

I used a carb, choke and intake cleaner. it does pretty well.

When was the last time the injector seals were replaced? They could be leaking and causing the rough idle. Also worn or leaking injectors can cause the motor to skip and miss at idle.

YotaJunky

I'm not sure if the PO did them. I haven't since buying the rig early this year. I was told by the head technician at a dealership who looked at the fuel system for more than an hour, that the fuel pressure was ideal, even during a running test, and that he didn't think there was any issue with the injectors, fuel pump or fuel pressure regulator.

Troy