mikedog

I have a weird idle problem on my '88 PU.

The idle will cycle back and forth about 50-rpm's two times a second. I have it set at 700rpm in neutral per factory specs and it will cycle back and forth between 700-750-700-750 and so on. It has always done this since I've owned it (almost 3-years).

Here is what I've done to the engine since I've owned it.

1. Replaced the intake gasket.

2. Rebuilt carb and replaced carb baseplate.

3. Cleaned out EGR and replaced gasket(s).

4. Replaced all vacuum hoses.

5. Replaced vacuum advance valve on dist.

6. New PCV valve and hose.

7. New plugs, wires and dist. cap.

8. Adjusted valves.

After doing all of the above, the engine now runs great. It runs very smooth and has alot more power. However, the idle speed still pulsates between 50-rpm when idling.

The only other things I can think of now that may still be causing this is one of the VSV's, BVSV's or one of the emission control devices attached to the carburator like the EBCV and EACV.

Has anyone here experienced this kind of idle speed problem with their 22r? If so, what did you do to correct the problem?


Thanks.

mikedog

ttt

Plays_with_Toys

That's wierd? I don't what could be causing it. Did you also change your air filter? Does it only do it during certain weather (cold vs. hot)? Could it be your tachometer isn't reading right? Or is the RPM change audible? I would try tightening the ground on the tach and check its connection into the green plug.

mikedog

Plays_With_Toys,

Yeah, that's just it. The whole engine will cycle back and forth about 50-100 rpm's when idling. I replaced the stock filter with a K&N not to long ago. Stock airfilter or K&N, it does the same thing. It does this mostly when the engine is hot at operating temperature.

I definitely know it's not the tach or the connections to it giving me this impression. I can visibly/audibly see and hear the engine rev back and forth 50-100 rpm's when it does this.

I wouldn't mind if it did this all the time. I'd figure that's just the way an old 400K mile 22r engine runs. However though, sometimes it will idle ever so smoothly and steadily at 700 rpm it's almost like driving a Lexus! Okay, well maybe not "almost" but you know what I mean. LOL!

Plays_with_Toys

When did you last change your timing chain? Maybe your timing is off by one tooth? I don't really know what the problem is. I haven't even figured out my carb problems yet...

JustAnotherJodieFE

You may try this....I just found this problem last month and am rebuilding as we speak (type).
When the engine is running, take your oil cap off and see if there's any change. I'm not sure this could be causing your problem, but I thought I'd throw it out there.

mikedog

Plays_With_Toys,

That's kinda what I was thinking too. Maybe the timing chain has been stretched too far over the years causing the engine to rev up and down when idling. I'm currently thinking it's either the timing chain and/or one of the exhaust valves that's causing this idle problem. I've pretty much went through everything else on the motor.LOL!

From all the horror stories I've read on the Toyota boards of worn-out timing chain guides on high mileage 22r engines, I guess I got lucky with this particular engine. Carefully keeping my fingers crossed though. LOL!

If you'd like to share, I very curious as to what type of carb problems you're having with your truck? Except for some small choke adjustments I still need to make on mine, I think I got the carb on mine running pretty darn good.


JustAnotherJodieFE,

Thanks for the tip. I'll try it to see if it helps when it starts to cycle back and forth at idle.

HurleyBoy

hey mikedog me and you might have the simular problem here..

i have a 22r-e in my 94 which broke over 149k not too long ago and sometimes when i start it up it will rev itself up and down for a little bit then calmly drop down to 1 grand and sit there idleing...however if i put water in my raditor all the way to the top then it won't do it for a while...but after 3 weeks to a month it will start...now i dunno where all that water goes cause i watch it after it fills up and it dont drop at all it just sits at the top of the radiator cycling...anyways thats my problem.

mikedog

I believe you can check the ECU trouble codes on a '94 22re if I'm not mistaken. Idling at 1K rpm sounds way too high to me. IIRC, I believe your idle speed should be around 700-750 rpm at operating temp. I usually idle above/around 1K rpm only when my engine is cold. Once its gets fully warmed up though, it should idle down to around 700-750 rpm.

Have you ever cleaned out the throttle body? They tend to get clogged up with carbon inside the idle air control passages after so many miles.

HurleyBoy

when i mean by 1k i went by this...you know on the tach where it goes 1 then a dash 2 then a dash 3? etc...anyways when my truck warms up the needle sits leveled with the 1. sorry if i didn't word it right

Plays_with_Toys

My carb problem is that if I drive around and have the car at normal operating temp and then come home (or where ever) and shut it off for 20-25 minutes, when I go to start it again it won't start. Its flooded. I have to crank several times and usually resort to a flood start (holding the accelerator down and cranking) which will fire it up. If I do get it started without that technique, I still get alot of black smoke and raw fuel smell. Also in the winter time, when I start it, it idles really ROUGH. I have a manual tranny, and when it is in neutral the shifter wags back and forth a good inch, maybe inch and a half to each side for about a minute. Sometimes when I start it and it does that the engine will quit after a few seconds, then I have to restart it. I haven't driven my car in a week and half now, but before then, I hadn't noticed too many problems with it. Did you ever experience something like that?

Macius

does this happen at all when you hit the brakes, cause if so, you might have a disconnected or broken vacuum line that goes from your throttle body to your vacuum brake booster. just a thought... might help you out

flecker

Hey Mikedog, I see you have pretty much covered the vacuum lines wich would be my first guess, and I don't see it being the timing chain (you would have alot of rattling going on). Also you adjusted the valves to .008 intake and .012 exhaust (unless you have a cam with different specs)... Have you checked the advance on the distributor or perhaps the ditributor is out of synch? when you did the valves did you notice any lobe wear on the cam? just some thoughts...