Hey men, I did a search for this and didn't see anything close to what mine is doing so I thought I would ask.

I just bought this 4runner and the previous owner said it was rebuilt last Jan. It idles perfect when the engine is cold but once it starts heating up it starts loping from 700 to 900 rpms. Sometimes it will idle 1100 to 1400. I have cleaned the maf sensor and triple checked to make sure the vacuum hoses were hooked up correctly. I have installed new plugs and wires also. When I first got it, it was loping from 700 all the way up to 1300 then back down. I put a K and N air filter on it and now it only goes up around 300 rpms.

What do you guys think it is? I appreciate all your help and thanks in advance.

 

https://www.yotatech.com/search.php?searchid=8436133

 

does sound like a vaccum leak, also make sure all the clamps are tight around the mas air flow, also can be a little hole from rubbin a pice of hose on something, there was always a little trick on honda's (or something with a map sensor, take the intake off, leave it running and put ur palm over the throtle body, if it dies u have perfect vaccum, if it doesnt die or starts loping there is a vaccum leak and u should prob be able to hear it suckin mad air. dunno if this helps and never tried it on a mass air flow sensor motor.

pat

 

I don't know if it matters or not but when u take the oil fill cap off while its running it blows a little oil out of the hole. I had a guy tell me this was called blow by and it needed to be rebuilt.

I will take some soapy water and spray all the lines to see if I can find anything.

 

xxx, that link u posted doesn't take me anyhwhere. it says there is no matches found.

 

I figured out something this evening working on the 4runner. It only lopes when the brake is mashed in. So I guess that narrows it down some. What do you think the culprit is?

 

Four things to check

1. Is your idle set too high.
2. Is your coolant level low.
3. Is you TPS working correctly i.e within spec.
4. No vaccume leaks, but sounds like you've gone through this step.

Those are the first places I would start with.

Here is a link on the same subject

https://www.yotatech.com/forums/f116...d-22re-230758/

 

Had the same problem on a 93 p/u ... mined turned out to be the idle was just set to high... cranked the EFI idle speed adjusting screw down to specs. mine kept working loose, so put alittle teflon tape on it... never had the problem again.

 

had the same problem with my old 22re and my new 3.o the 4 banger was just low coolant....the 3.0 straigtned out with a new thermostat....deffinatley could be a leak some where..

 

X3 on the idle speed set too high, detailed explanation below:
- http://www.4crawler.com/4x4/TLCA_Tru...ech.04.09.html

 

My check engine light has been on and I ran across the paper clip deal and tried it. I am getting the following codes: 24, 25, 31.

Would 1 thing cause this or would it be multiple things. I don't want to just start putting money into it and it not be the right thing.

It was only loping yesterday when the brake was mashed but now it does it all the time except when its cold.

 

Hey Bill, I had done my own homework on this 93 I had... engine had been replaced in it,an your loping issue was one of many aggrivating problems I had... funds were limited then as much as time... fix one problem at a time an don't, fix one at a time an take a few deep breaths, work on the simple an obvious first, an you'll get it... on the codes, I did end up replacing the down stream O2 sensor, which resolved a couple other things, most importantly mpg. Don't forget to reset your codes... "ingition off, pull EFI fuze" for a few seconds... if you didn't get it, don't worry it'll let you know. Hope this helps along with other great info these guys are pouring in.

 

curious on how low coolant affects this issue?

 

ECU reads the coolant temp sensor to determine if the engine is hot or cold. If the coolant is too low or there is air bubbles in the system the temp sensor will not accurately tell the ecu how hot or cold the engine is because it's not covered with coolant.

 

Let me guess, this guy also offered to rebuild it?

 

No he didn't offer to rebuild he just said it needed rebuilt.

 

call him up and ask him to explain how a 22r engine that was just rebuilt and has some crank case pressure but still does 170psi on a compression check and has a brand new head.

But I already know he answer to that anyway. A little blowby is normal as no piston ring seats perfectly. This is one reason why there is a positive crank case ventilation system on an engine.

Without actually doing compression and leak down checks, he should not be saying the engine needs to be rebuilt.

 

Ok new list of symptoms and things I have tried. When u crank it up cold it idles normal, once it heats up it lopes from 1000 to 1300 rpms. If u hit the brakes it lope from 700 to 900 rpms. I put a maf sensor from a junk yard on it and a throttle body sensor. No help.