YotaPower

Ive got an '86 4runner sr5 w/ a 22re. It runs LIKE A CHAMP.

Especially when started cold. It cranks right over, starts up, 750-800 rpm. Sounds awesome, feels good, strong, etc. No problems there.

However, once warm, starting it up causes the engine to shudder at idle, revs dive, and it has even cut out a few times. Giving it some gas cleans it up while the engine is reved, but it always drops back down and shudders some more. Once a load is applied (ie, i put it in gear and go) there are no more problems what so ever

just today, i drove it to frys, got what i needed, then came out to leave. It almost didnt start, feeling alot like the rough warm idle described above. Again, any apparent problems were gone once the clutch was dropped and i started to go.

I have tried to do a search both here and other 'yota forums with no solid answers. This thread has lots of ideas, but no definite answer. Ive checked what common problems i can find:

-cleaned the throttle body
-checked/adjusted TPS
-cleared out the IAC (opened it up, too, it was so clean, i would have eaten out of it)

one response to a 'rough warm start' thread was that it ended up being the head gasket. im crossing my fingers that isnt the case. Could the cold start fuel injector be the culprit? if it was stuck in the ON position (always firing even when warm)

Anyone find a solution to this? Im beating my head against this issue...

Oldfart

Good advise and I assume it's an EFI and 1000 to 1200 rpm cold is normal

YotaPower

maybe i wasnt clear enough. It idles fine WHEN DRIVING even while warm. For example, after some freeway miles (engine at operating temp), stopping at a stop sign or red light, means the engine idles at a healthy 750-800.

its starting it WARM that is the issue. Cold starts are no problem. Warm start means the engine stumbles, the rpms take a dive, (running very rich?) and the engine may even cut out if no gas is applied, or i dont put it in gear and go.

and yes, its an EFI. ill double check the idle adjustment when warm.

Oldfart

I know it sounds strange but the idle screw is only supposed to effect a cold engine after that it should make no difference but don't feel bad I'm having a similar problem I've been told by a 25 year toyota tech to check the reed valve.

YotaPower

bump, and no i dont have any cold start problems.

myyota

Unplug the thermal time switch after you have the engine warmed up and see if the problems goes away. When the thermal time switch goes bad it usually keeps the cold start injector from working, but it can go bad and be stuck on allowing the cold start injector to star on all the time. I would also recommend that you pull the cold start injector out and clean it, they get covered in carbon build up.

YotaPower

Ive since cleaned the cold start injector, partially cause it was easy to do. ill try disconnecting the thermal time switch when warm. im guessing the thermal time switch is just the electric plug on the back of the cold start injector assy?

If so, how do i disassemble the fuel line to the cold start to replace it? isnt it going to be pressurized?

myyota

No its not, the thermal time switch is what tells the cold start injector to come on or shut off. Its located below the upper radiator hose on the front of the intake. There will be two sensors there, the thermal time switch is the larger one.
You can also unplug the cold start injector if you want, its easier to get to.

myyota

I just noticed you live in Orinda, I used to live in EL Sobrante, not all that far from you, but now i live in Idaho.

YotaPower

there is obviously a communication breakdown going on here. im a little confused. but from what i read, my idle adjustments are all sorts of foobar'd?

I dont witness a higher idle when cold, it only jumps up to 750-800 when cold started. from what i understand now; the cold idle should be higher, warm idle should be the 750-800. however, the warm idle is 750-800, and the cold idle is also 750-800.

when i set the idle before: i let the engine warm up, then set the idle 750-800. once i let it cool down, it still idles at 750 when started.

i have checked the IAC (same as AAV as i understand it), and i cleared it out. it now allows coolant to flow. also, both hoses are the same temp (warm/hot) once the engine is warmed up so i know its flowing.

im going to try adjusting my idle just one more time. it would make sense that if cold is supposed to be higher, and my warm start stumbles, that my idle is actually too low.

then ill try disconnecting the thermal time switch.

thanks for the help guys, i hope i can figure this out.

kev

air flow meter sensitive to thermal load? try swaptronics ! maybe the door to the afm is slightly open after it is warm and will not close completely until the temp drops..
Just a simple suggestion....kev

YotaPower

ok, im sure idle is set properly now. cold start at 35-40F meant an idle around 1100-1200rpm. Havnt really had an opportunity to try a cold start at ~70F. its just not that warm outside. ill see what she does with a warm start.

YotaPower

according to the FSM, my AFM is bad! i got a tip from a co-worker that had the exact same issue. a new AFM fixed it for him, so i decided to check it out.

YotaPower

uhh, no.

wheres the diag connect? and I dont know how to set the timing...ill poke the FSM for these. im guessing this process is just putting all adjustments in spec to troubleshoot from?

deprivation

Yotapower!

Have you solved this yet? I have exactly the same problem. Runs great. Idles and starts perfect - hot or cold. But a semi-warm engine re-start idles rough - almost dying - until I've warmed it up again. I don't think most of the people here replying seem to get what you're trying to say.

noglu10

I understand what you are saying. I have had this problem for over 5 years with no resolution. All the forums (car and truck I have read concerning the 22re have not been able to resolve it) I have an 85 celica gts and a 90 pickup with the same 22re engine. The problem is just like you describe. I can start it fine when cold and runs great. I drive it 10, 20 100 miles with no problem. I stop it for a couple of minutes and it restarts and runs ok. I stop it for 15 to 60 minutes and it restarts and runs rough. I have to keep pumping the gas pedal and finally it picks up and runs ok. A couple of times I have pulled out in traffic too soon and have had to pull over to the side of the road and wait for the condition to go away. I have had this problem on both vehicles. I have never fixed it on the car but I am sure the problem with the truck was resolved with a new air flow meter. I have replaced the following parts on the car: afm, fuel injectors, o2 sensor, plugs, igniter, coil, water temp sensor, egr valve. Checked the cold start injector and timer switch. Checked the tps adjustment. The one thing I have not done is pull and check/replace the fuel pump or the fuel line. I checked the fuel pressure but not while it was failing. Only "one" time did it not fail on a warm restart. It was during the summer and I was stopped at a traffic light. When the light changed it did not repond when I pushed on the gas. After creeping along for a couple of hundred yards it suddenly picked up and I continued with no problem.( Once again not sure if it was the warm tempeture or maybe lack of fuel pressure or air flow) Still waiting for a solution. I have a shop manual and can check/adjust almost anything if necessary. This problem seems too common for it to be so difficult to diagnose. I feel everyone else's pain. One thing I might explore is to hook up a fuel pressure guage between stopping and a warm restart to see if the pressure is somehow leaking down. Just a suggestion.

Tom

noglu10

Update to the warm restart idle issue. I know that I once fixed this problem on my 90 pickup with a new afm. However when I replaced the afm ( with a remanufactured one) on my 85 celica gts it was not resolved. The other day I checked the afm on the celica with an ohmmeter and the shop manual while the motor was cold and not running. The resistance values were off (too high) with the flapper closed and then while opening it. I removed the black cover on top of the afm and noticed that if I put tension on the "copper tab" that runs on the printed circuit board the resistance values were within specs. I removed the tab and slightly "bent" it down so it would better contact the circuit board. I reinstalled the tab and re-installed the cover. I rechecked the values and they were within specs. I have run the car a couple of times with no failure. I am not ready to say it is fixed but I am pretty sure these remanned afms are not the most calibrated parts on the market. The problem I had on my truck years ago was the tab assy had slipped off the circuit board completely. I had to go loosen the clamping screw and reposition the assembly per the resistance check using the shop manual. I had gone to the junk yard years ago and gotten the connector assy along with about 6" of the wire harness that plugs into the afm and made a test jumper which allows me to check the afm resistance without having to put the meter leads on the pins of the afm. I also got the tps connector and partial harness for the same purpose. Will update if it does or does not fail again.

Tom

Duffdog

the answer to fix your problem is: You need a NEW IAC. A few years ago I took my other 4runner to the toyota shop foreman who told me that many 22re's have this same problem, but the owners just decide that it isn't a problem when they find out how much the repair costs. Unfortunately, there is no substitute for this part-- If I remember correctly, the dealer charged 370~ for it. I even tried getting a used one off a "low mileage" 22re. That made the idle different, but it still took a bit to get it going during a hot start. It would start at about 300 rpm and slowly, gradually increase the idle until it was right around 800. Apparently, if you get a new IAC, it MUST be brand new and it MUST be from toyota, or, your truck will idle screwy forever.

PS, I would never in my life trust a remanufactured AFM to work for any length of time.

noglu10

Bit the bullet and replaced the fuel pump. Have driven it a week in hot weather with no problem. When pump was removed from the tank it still felt "hot". Only problem removing the tank from my 85 celica gts was the high pressure fuel line coupling. It was very "stiff" when loosening. Had to tighten and loosen it when taking it apart. The treads were not damaged and it went back together ok. I think the fact that it had not been taken apart in almost 27 years was the problem. The inside of the tank was clean as well as the screen under the pump. Will let you know if it does or does not fail. I'm pretty comfortable that this may be the fix.

Tom

noglu10

I'm pretty sure it is fixed. Has not failed and I have been driving vehicle a lot recently in hot weather. Wish I had replaced the fuel pump sooner.

Tom