Dorian

Happy New Year!

While driving my 4runner (90' 5spd manual sr5 4x4 v6) yesterday I noticed something quite odd. After a short 6 mile drive which included getting my truck up to highway speed, the idle speed began to surge under street driving. While at traffic lights the idle would surge from 800 to 1200 in a steady cycle until I began to drive again. This never happened before.

After spending the night searching the board I noticed that this is a problem that occurs with excess air leaks. This morning I drove around and had no problems with the idle . When the truck started it was at around 1500 and after some driving calmed down to 1000( which i believe is about normal...unfortunately i never noticed what it used to idle at before 2 days ago). However now after a minute of driving the CEL comes on. I dont believe this came on yesterday when the surge was occurring however im not sure of that.

I recently had the headgasket replaced on the recall along with the timing and drive belts (12-12-02). I have driven about 3000 miles on it since that time. What action should I take to correct this problem (CEL the surge doesnt seem to happen now but may come back)?

As always thanks for an help
Dorian

AgRunner06

You need to pull the code for the CEL. The easiest way is to go to Auto Zone and have them pull the code. They do it free of charge.
Someone correct me if I'm wrong. On my car I was able to jump two of the holes in my diagnostic hookup. I used a paperclip to jump the TE1 and E1 holes. I then turned the key to the on position and then my check engine light would blink out the code. I know that your car is three years older, but my guess is that yours would be the same as mine.
There's no way of knowing if the surging is related to the CEL until you get the code for your CEL.
Good Luck.

Dorian

Well I've driven around for a few days since the orignial idle surge happened. It has never returned but the CEL light that came on the next day is still on.

I took the truck to the dealer to run the check for the codes. He came back to me with a code 052. He said it was an open circuit and meant some kind of knock.

He also said that the mech was going to reset the CEL. When the truck was restarted it came back on.

Any ideas.

My idle after warm up is just above 1000. is this too high? could this be causing the CEL?

Thanks
Dorian

Optimus

Sounds like your idle speed is set too high, or something is causing it to be too high. I have an article on this on my website. Note that it took a couple years before the actual cause was determined, high idle and stepping on the brakes causes the injectors to cut out. Up until then, myself and many, many other people who emailed me were baffled by the problem. Though my article says to bypass the brake light switch wire away from the computer, this is a last resort at this point. The most common fix is to simply turn the idle speed down when the engine has warmed up fully. There should be an underhood sticker stating the RPM's at idle when warm. It's probably around 800. The fuel injector cut-off is about 1300 or so, but I'm still not sure exactly where. See my article for more info:

http://www.geocities.com/toyotashawn/bizzareidle.html

Thanks,

Shawn

Dorian

Shawn,
Thats a great site. Exactly what I experienced. It's strange that it only happened that one morning when I had my truck out. Is this similar to what you experienced, that it surged sometimes and not others?

I noticed that when I got my truck back from the dealer that aside from smelling smokey (gotta love a mech that smokes in your ride) the radio stations and clock were all reset. Does this mean that they probably disconnected the battery to try and reset the ECU?

I've read on many posts here (Dr. z's) that is the EFI fuse is pulled for 15 + minutes that the CEL light may go off but the error codes remain stored in the ECU. That the only way to properly reset the ECU and theCEL is to have the mech actually clear it out on the handheld computer unit.

Would this apply to the ECU on a 1990 4runner? Or can the power plug just be pulled on these older models?If this is true its more than likely that my smoking mech just disconnected the power erroneously, believing that this would reset the ECU.

Should I try a trip to the Autozone for a reset?

Also should I try to lower my idle to around 800 myself or just leave it.

Thanks for any help
Dorian

Whats ECU anyway???

Dorian

I stopped by an AutoZone and they told me that my 90 4runner was too old to read. They also said they thought a battery disconnect would reset the CEL.

I realize this doesn't seem to be too popular a subject. Just keeping my situation updated and fishing for advice.

Thanks
Dorian

Dr. Zhivago

On OBD I vehicles like yours, pulling the EFI Fuse or disconnecting the battery will reset the ECU (Engine Control Unit) and clear the codes stored within. It's the newer OBDII Vehicles (Any vehicle manufactured for sale in the US after 1996) that need a Scan Tool to Reset codes.

I would adjust the idle speed to a slightly lower RPM than 1000 if it were my truck. 750-800 seems about right if you have an Auto Tranny. 650-700 for a Manual.

Hope this helps.
Dr. Z

Dorian

Thanks Dr. Z
The dealer disconnected the battery and I also pulled the EFI fuse. I guess the CEL is on for a reason then because it still comes on.

It comes on once I shift into gear and start to drive. Sometimes it comes on in 1st other times it comes on in 2nd. If I start the truck and then rev the engine to about 3000 suddenly it will also pop on. I never hear anything like a PING or a KNock. CEL always stays on until I turn off the truck.

I adjusted the idle screw 1 full turn in (clockwise) to reduce the RPMs at idle to 800. I guess since I have a Manual Trans. I should go lower. I couldn't find an idle rpm on the door or the engine.

I'm hesitant to lower the idle however because perhaps there is something wrong thats causing the elevated idle. I checked several threads about vacuum leaks could this be causing the knock sensor to come on. I still havent had a reoccurance of the surge.

Thanks for any other ideas
Dorian

Optimus

For whatever reason my post I tried to do earlier today didn't make it. Pulling the EFI fuse or disconnecting the battery for 30 seconds will clear the codes. You don't need to go to a dealer or autozone and pay to do that. Sounds like the dealer pulled your battery cable when they did it.

Didn't you post on the off-road board about this a while back? Weren't you getting a code 52? If so, that's a knock sensor and the wire is likely bad. Dealers usually replace the wire when doing the head gaskets. Did they not do yours? The wire gets brittle over time.

Set your idle speed to what it's supposed to be at. There should be a label under the hood. I wouldn't worry too much about "other issues" causing the idle to be high. It isn't all that uncommon for the idle to change a little over time after a major engine repair.

With your RPM's set at 800 right now if you are experiencing the exact problem I described on my page, the problem will be gone. And to answer your previous question, yes sometimes it would happen and sometimes it wouldn't. Either during the same drive or different drives different days etc... It wasn't consistent all the time. Sounds like yours was borderline in terms of being set too high.

Dorian

Thanks again Shawn

I did have my head gasket replaced on the recall less than a month ago. I just piggybacked off a "code 52" post on the off road board in the last couple of days to figure out what the knock sensor is.

I looked at my invoice on all the work I got done on the head gasket. All which was covered under warranty.

i have the following part listed under the head gasket section

82219-89103 Wire, Sensor.

I searched the web for this part number and I came up with "Knock Sensor" for the description. It looks like the dealer listed it out and didnt do it.

I guess I will be making yet another trip back to them to fix this.

If Jay is out there...I have a question. Are all the parts listed under the invoice section used? If so I guess I got a bum part or it wasn't replaced at all...How can I tell if they even replaced the head gasket or looked for the wear that may have occurred?

Thanks for any info

Dorian