socal_style

My 88 4runner 22re, started doing some weird stuff lately, and it is progressively getting worst. It used to happen once in a long while, but now it is consistent. when I dive very slow the problem is not present, but if I have to accelerate above 3k, it seems that the throttle gets stuck on high. Even if I press the gas a few times, it will just stay high.

The check-engine light goes on when the throttle gets stuck. But I can not pull a code. I read the directions on 4crawler to get the codes, but I don't get the check-engine light to blink. GRRRR!

On my truck, the diagnosis plug located in the engine bay near the fuse box looks like this. I stuck a paper clip into Fp & +B, then turned the ignition towards the on part, all lights go on, but no blinking. Am I doing something wrong?


Any pointers will be greatly appreciated.

abecedarian

yeah, put the jumper between the T and E1 terminals then turn the key to on, don't start the engine.
the FP and B+ terminals are "fuel pump" and "battery +" respectively so you jumpered to turn the fuel pump on.

socal_style

^ DOh! Ill be back.....

socal_style

I think I have a code 12, 25, and 26. I uploaded a video with the blinking check engine light. It is only a little over a minute long. Does this look like a 12 and 25?

http://www.youtube.com/watch?v=ZaabLzZwPAc

According to this website: http://www.off-road.com/toyota/tech/codes/index.html
Code 12 can be:
RPM SIGNAL-NO SIGNAL TO ECU FROM DISTRIBUTOR ("Ne" OR "G") AFTER ENGINE HAS BEEN CRANKED
--DISTRIBUTOR/CIRCUIT
--STARTERSIGNAL CIRCUIT
--IGNITER/IGNITER CIRCUIT
--ECU

Code 25 can be:
AIR/FUEL RATIO LEAN INDICATOR--LEAN SIGNAL SENT TO ECU FROM O2 SENSOR
--INJECTOR FAULT(S)
--FUEL PRESSURE
--OXYGEN SENSOR
--AIRFLOW METER OR MAP SENSOR
--IGNITION
--ECU

Code 26 can be:
AIR/FUEL RATIO RICH INDICATOR
--SAME AS ABOVE
--COLD START INJECTOR

Kiroshu

you prob got a bad tps plus a sticky throttle. clean throttle and get a new tps and it will prob fix it.

socal_style

abecedarian- Thanks for the pointers on diagnosing.


Kiroshu- Thanks for the pointers too. I am planning on cleaning out the throttle body with one of those sprays that they sell at autozone, to flush the inside pretty good in case there is some grime or other crap in there. As to the TPS, should I test it before I replace it, or should I just get one and try it out?

To clear those codes, do I just disconnect the batter for a while?

Kiroshu

If you pull codes and one of them is tps then yes you need a new tps but depending on price i would recommend one anyway if thats the origianl one.... if you get one make sure you get one from dealer otherwiase you will ahve fun adjusting it.....

Kiroshu

ok in those codes 96% of the time the problem is the first thing that it says.

socal_style

Hmmmm......

Well the codes don't actually point to the TPS. They point at a bunch of other stuff. But I should look into replacing it. I am still running the original one. I may also replace the O2 sensor, although I don't think that is actually the problem right now.

Kiroshu

ok so the way i see from the codes if you want to be a parts replacer..... replace the distributor cap and rotor button, o2 sensor and tps, along with cleaning throttle i would say should fix your prob.

Kiroshu

rpm signal is relating to tps cause thats one of the ways it sees rpms besides crank sensor....

socal_style

^ Thanks....... Ill keep you posted. I'm going to the yota dealer tomorrow. Hopefully those parts are in stock, or else I will be ordering them.

Kiroshu

i know its money but thats the price of having old trucks... trust me i know.... but just look at it this way if you had an 88 domestic or somethin you would be spending alot more....

Matt16

FWY= freeway= highway????

socal_style

^ yeah, FWY= Freeway. But the problem begins when the engine is warm and I have to accelerate, as to climb a hill.

Update.... I looked at the distributor cap and rotor, as well as the wires. The cap and rotor looked good. My records indicate that I replaced them 6 months ago, and this truck is not even a daily driver. I noticed that One of the spark plug wires was scuffed and had a kink sort of thing, so I replaced them (I have life time warranty on them). Cleared the codes on the computer. Drove the truck around, and the problem continued. except that I am no longer getting any check engine light.

Im thinking of switching the O2 sensor with a universal one, as its 1/3 the price. Should this o2 sensor be okay?

Next, I went to the Yota dealer to order the TPS sensor and some other nick nacks. The part was not in stock, but I should get them during the week. Ill keep updating this thread.

If anyone has any other ideas on what I should look at, please post.

socal_style

Sort of an update.
I drove the truck around a little this weekend, and the check engine light came back on, and the throttle started sticking again.

I ran another diagnostic and found that code 12 is no longer present. Yay!...but I still have code 25 and 26. TPS sensor should be getting here from dealer tomorrow or the day after and I am hoping that will take care of this.

In the meantime, I used throttle cleaner to get rid of the grime inside the throttle body. It was a little dirty. Then I took off the TPS (by the way, it was a bitch to remove the lower screw). Got the TPS sensor out and noticed that if I manually moved the thing, it would get stuck half-way as it returned to its resting position. I cleaned it up, and I am thinking of putting it back temporarily until I get my new one.

Do you think the binding is what was causing the throttle body to stick?

socal_style

I got the TPS, and some other miscellaneous clips to replace old worn and broken ones in the engine bay, all original yota parts.

The bad thing is that I have not been able to set the TPS yet.... GRRRRR...

I tried to insert the feeler gauge and noticed a problem. The stop screw on the dashpot was not hitting the stop part.
Does anyone know if it is possible to replace the Dashpot without actually removing the entire throttle body? That little rubber part is also torn, and the cylinder that sticks out is loose and wiggles around. Is it supposed to be that way?

Im thinking of probably just removing the whole throttle to place a new gasket in there and just give it a super good cleaning. Any Suggestions?

socal_style

Anyone?

socal_style

The Good:
Okay, I installed the TPS. And no more check engine codes have been appearing.

The Bad:
I drove the truck around about 10-12 miles, and then the high rev problem started again. I pulled up to take a look at the truck as the problem continued and I noticed that the throttle stop rod on the dashpot would not go down, to allow the throttle to rest at the idle zone. I pushed on the rod down with light pressure and problem appeared to go away.

I drove around some more, and problem happened again. The rod from the Dashpot was again stuck, not allowing throttle to go lower.

I'm thinking that the Dashpot is bad. I'm going to try lubing the bastard and massaging up and down to see if it fixes this problem.

Does anyone have any suggestions?

abecedarian

if you're not getting any codes after clearing codes... that may be a good thing.

basically, with the dashpot, you want to make sure idle speed and timing are set properly (should be 5BTDC on the 88 22re with the diagnostic jumper installed and ~750 rpm without the jumper)
then you rev the engine up to 2500 rpm and pinch the vacuum line to the dashpot closed and then release the throttle- engine speed after releasing the throttle and cutting off vacuum to the dashpot should be about 2000 rpms
then release the 'pinch' on the vacuum hose and idle speed should drop to normal within 1-2 seconds.
If the engine doesn't hold ~2000 rpms when the vacuum line is pinched or doesn't return to baseline idle speed within 1-2 seconds, the dashpot may need adjusted (so it holds the proper speed with the line pinched) or replaced (if it doesn't hold the proper speed or let the rpm's to return to idle within 1-2 seconds).