BajaRunner

Edited to clean up my blabber

Code 22 and 41 have been fixed by setting the idle lower. A/C surge was also eliminated by lowering the AC idle up adjuster.

Code 71 has been my problem.

What I've done:
1) Cleaned entire plenum, EGR valve, EGR temp sensor and connecting tube. (Completely gunked)
2) Tested EGR valve by connecting vacuum line directly to it. (Valve opened correctly, could feel engine stumble)
3) Tried testing the EGR modulator as best as possible via the FSM. Ports are all clean.
4) Vacuum reading to top of EGR valve seems non existent when engine is warm and on high idle (I used my vac gauge and didn't see any movement)
5) Vacuum reading to EGR is higher when R port is plugged into active vacuum, which is good.
6) Tested all VSV's.
7) Tested to make sure that temp sensor changes resistance with temperature changes.

Im still stumped on how the VSV is incorporated into the EGR system. My vacuum diagram doesn't show how it is connected at all. It shows that the EGR is connected to the modulator via the TVV (Thermal Vacuum Valve).

So when the EGR valve opens, and sends gases into the intake plenum, what sort of temperature should it be at, and what resistance reading should I get from the temp gauge?

Are there any other trouble areas? I have a hunch that the valve guide within the EGR is gunked and is getting stuck from time to time.

BajaRunner

Since the coolant is SUPER high and over flowing....

Could it be the thermostat? Air in the system from loosing some fluid? (I didn't burp it yet).

Where is the engine temp sensor located and does it go out, or is it more of a connection issue?

I will follow the TPS testing and adjustment found on Rogers site.

I tried lowering my idle, and the surging stops when the brake pedal is depressed, but if the AC is on, it still surges.

myyota

If you got the cleaner that you used in the TPS, that`s bad and you probably damaged the TPS and will need to replace it. Try replacing the thermostat, if its coming out the over flow and see if that helps, thermostats are cheap. For the EGR temp sensor, unscrew it from the top of the EGR and clean it, they can get carbon build up on them and not read properly.

BigSwole

just an idea for you to check...

unplug either the EFI fuse (15amp) or your neg side battery cable, while your waiting make sure your TPS is plugged up.

hook it all back up and check the codes again...

code 41 is as if the TPS isnt hooked up...

its the code 51 that will get you...go ahead

ask me how i know

BajaRunner

Well, all these problems started happening after I cleaned the TB and IACV... so I probably screwed something up... :/

I had to clean because the idle was rough with a warm start. That issue is completely gone, but now I got a bunch more issues!

I just drove the truck (after I did the cleaning about 40 miles) and it runs great, except for when I hit the brakes, and now all the CEL codes are freaking me out.

The thermostat is new, but I will double check it is the right one.

BigSwole

i have been going through the same thing. my TB was gunked up like 1/2" or more, once i cleaned it fairly well, it started shootin me all kind of codes...

just cleanin it allowed the codes to come through and now im able to start fixing my problems.

clear your codes and check again.

thook

^^^^Sound advice

If you're concerned you've damaged the TPS, then test it. If it's damaged, it'll show up on the meter. Run a forum search on testing. More than a gazillion threads on it. Either that, or ask BigSwole. I'm sure he's gotta pretty grip on it by now.......

BajaRunner

Thanks sounds good. I've been reading for the last 5 hours on things, but its almost too much information to comprehend. I've been writing all the stuff I need to do down.

I still haven't found any information why my coolant level would have gone UP. It seems like those with a Code 22 have a LOW coolant level.... (I guess mine could be considered LOW if all the coolant is in the overflow tank?)...

BajaRunner

And if someone can give me the location of the ECT, id be stoked.

thook

It's on the front of the motor. You'll see two sensors side by side. One has a brown connector (cold start time switch) and the other is green. That's the coolant temp sensor.

BajaRunner

OK thanks for the replies.

Something tells me that the Code 22 and 41 are related.

The 22 is causing 41...

The 22 is caused by the fact my coolant is all in my overflow tank, and it sure looks like the sensor isn't getting any fluid to it, causing the code to throw. I need to find out WHY its not moving through.

I opened the IAC yesterday and cleaned it, assuming that would have helped motion, but, for whatever reason its not.

Any areas/methods I should try to figure out how to get my coolant level back where its supposed to be???

My O-ring that is sandwiched between the IAC and TB needs to be replaced, but I called Toyota and NAPA and both said it didn't exist. Any part #'s?

thook

Nope. Codes aren't related. A bad coolant sensor or any coolant sensor issue won't affect the TPS. They're indepedent of each other. Both are necessary for fuel ratio, though. Now, if you had an ECU problem, that could cause both codes to be thrown. But, unless you're having an ECU or ECU connection problem, the two codes (as well your third) are coincidental.

With that in mind, here's a hypothesis for troubleshooting. In your cleaning of everything, possibly you've damaged the idle control valve and the TPS. If you have a block somewhere in the coolant system, this could cause very poor coolant flow causing way too much heat in the engine. This could possibly be your coolant sensor and EGR temp sensor code. There again, do you have the thermostat in correctly and not upside down? Just asking. I've heard of that happening before.

Some suggestions.....

Take the o-ring into an O'Reilly, or equivalent, and see if you can get a match. I've never disassemble the idle air valve, so I can't help with a part number and whatnot.
Test the TPS
Test the idle air valve

http://personal.utulsa.edu/~nathan-b...93throttle.pdf

BajaRunner

OK I just tested the TPS and its fine.

I followed the procedure in testing the IAC, and idle decreases as temperature increases.

The thing thats still weird is the coolant.... I tried to burp the system but the radiator just pours out coolant from the top!??!?!

I'll put the cap back on, and run it till it warms up. When I halfway turn the cap (with a towel) a ton of fluid spews into the overflow tank. It seems like the coolant motion is being impeded somehow.

I'll open up the thermostat housing and make sure its on there correct and functioning. Thanks.

Heres what I did to figure out whats going on with the coolant:

1)Opened up thermostat, put it in a pot and watched it boil. The T-stat opened before boiling, and its marked 180F.

2)There was coolant on both sides of the T-stat, which makes me think thats a good thing.

3)Turned heater on, tried to burp. Heater functioned fine, but the radiator pushed coolant off the top. Dont know if thats normal or what.

myyota

Stock thermostat temp rating is 190-195 degrees.

BajaRunner

Well, I turned down the idle, and the surging goes away.

However, when I turn on the AC, it goes up to about 1500 rpm. Way too high. I need to turn that down, but I am not sure where the ac idle up adjustment is.

Edit: Found the AC adjustment screw (right in front of your face) on top, near the "EFI" stamped on the intake plenum.

Right now, I got the idle (warm) at about 900 rpm, any lower and its a little "rough". Then when I turn the AC on, I set it to about 1200 RPM. No more surging when the brake is applied!

Coolant level looks good, the IAC gets hot when the engine is running, so its getting coolant. I am certain the IAC is also working properly.

BajaRunner

The head and valves were re-done about 5000 miles ago, and I really doubt the PO readjusted the valves after... I'm thinking that might have something to do with my not perfectly smooth idle. Slight tapping coming from the valves, but nothing major. I might do that this weekend.

The CEL's are off, but I've only driven around the block a few times.

Stag

I've been following your thread bc I have been having the same issue with the surging idle when the brakes are applied in my '87 4runner. I have read up on tons of old threads and is seems the main causes are the brake booster and a dirty throttle body. Would you say in summary that cleaning your throttle body fixed you idle prob? I ask because I just had some major brake work done (master cylinder, proportioning valve, rear drums) and I would think my mechanic would have noticed an issue with the brake booster. Thanks for any help on isolating the cause.

BajaRunner

Stag: I would say just turn down the idle screw first.

When your truck is running in neutral, what RPM is it at? If you hold the brake down, does it start surging up and down (RPM-wise)? If so, your brake pedal is sending a signal to your computer that "shuts down" the injectors and slow your idle. Your idle screw is saying to keep it up higher, and they are working against eachother.

What caused the problem I think is that the intake was so caked with gunk, that after I cleaned it, it started idling faster, and I had to turn the idle back down.

BajaRunner

Update: My Code 22 and code 41 are gone.

What I did:
1) Changed my thermostat
2) Burped the system
3) Ensured coolant was flowing to the IACV
4) Set idle to ~900 RPM
5) Set AC idle to ~1200RPM


Now on to code 71. I think I may have a clogged port that goes to the EGR temp sensor. I know nothing about the EGR except for what it does...I've never had to screw around with it.

On another note, does readjusting the valves help with idle smoothness?

Stag

My idle screw is completely screwed in. Meant to mention that in previous post. Sorry. And yes the idle surges when the break is applied between 800-1300 rpm. without the brake in idle is close to 1500 warm.