Just Got A MK3
 

Hey everyone, I'm new to the forums abd just purchased a 1986(.5) Supra MKIII. Drove great for the first couple of days and still does except sometimes when I start the car it does this "auto rev" thing where it revs from 1k - 2k repeatedly. Also it doesn't go away when driving the car, I drove it for 3 minutes and everytime I push in the clutch it starts again.

Our initial response was the head gasket but the oil looks fine so we think it could be the vacuum hoses? Today while looking under the hood I noticed one wasn't plugged in and I don't know where it goes..

Any help would be appreciated!

It doesn't have an auto rev thing lol. Sounds like your vacuum system is screwed up. Do you have a pic of this hose that's unhooked?

Sorry I didn't mean to imply that there was an actual auto rev thing. It is just Reving itself up on it's own.

I dint have any pictures of it but I will take some tomorrow and post them up. Thanks for the quick reply. I'm hoping it's something simple like a vacuum hose leak.

I've seen that type of thing multiple times in other cars the surging is almost in every case that i have delt with ended up being vacuum, or a tps. have you put your finger over the hose to see how much vacuum its pulling?

Here are some pictures. Hope these will help you guys help me! lol

http://i23.photobucket.com/albums/b396/Codal/009.jpg

--This one is on the left side of the engine bay (passenger side) and comes out by the Fender, I have no idea what it goes to. The other end isn't connected to anything..


http://i23.photobucket.com/albums/b396/Codal/005.jpg

--This is about in the middle of the engine bay and had nothing attached to it so we just put a cap over it for now..


http://i23.photobucket.com/albums/b396/Codal/001.jpg

--This is just below the first picture I posted, if I remember correctly the hose on the other side leads to the canister.. we put a cap on it because nothing was connected to it..




Started the car up today and it ran just fine.. it only revs itself up on occasion. Hopefully finding the right spots for these will fix it.

Can't quite see what I'm looking for in pic 1.

IIRC, the line in pic 2 goes to the BVSV (two pronged vacuum valve on the thermostat housing, they're common to break so yours may be non-existent at this point). The line in pic 3 that runs off of the MAF Sensor should connect to the other end of the BVSV. If there is no BVSV, you may be able to hook the MAF Sensor directly to that nipple on your intake, but then there would be no regulating when the unburnt vapors from your charcoal canister are allowed in your intake.

Thanks for the reply.. My friend and I looked at the chart thats on the hood and we figured that it would go to the BVSV but we looked for it and we are unable to find it..

Is this the BVSV...?

http://pic20.picturetrail.com/VOL14/.../378136615.jpg

If so mine is broke... I'll have to buy a new one.. do you believe that this will fix the reving issue?

Yup, that's a BVSV. It at the very least should help a little, although I can't say for sure if it'll completely fix it.

Actually, since you capped off the lines it probably won't change the revving. It will, however, help your evaporative emissions system work properly.

Since there are quite a few vacuum lines on the car, I'd suggest spending some time running through the engine bay and checking that everything is hooked up properly. I had to do this on my first 87 (N/A), and it really didn't take that long.

Click here for the vacuum routing diagram (note that this includes all the lines connected to the engine, but not all of them in the engine bay). Thanks to green7mgte for the link in another thread.

Check the rest of the vacuum lines. Here is the diagram.

http://www.cygnusx1.net/Supra/Librar...spx?F=1708&P=5

If you haven't bookmarked this site go ahead and do it. It has saved my ass on many occasions lol

The hose coming out from the fender is the washer fluid line.

The revving thing is most likely a defective, stuck or disconnected ISCV (Idle Speed Control Valve): http://www.cygnusx1.net/Supra/Librar...ction=FI&P=106

I did a diagnostic test..
 

So I'v been having problems with my 1986.5 MKIII reving itself up and we thought it was just a vacuum leak.

Tonight when I got home I ran a diagnostic lke cygnusx1.net says to and it came up with the code 43.

Code 43:

Starter Signal

Diagnosis - No "STA" signal to ECU until engine speed reaches 800rpm with vehicle not moving.


Trouble Area
- Ignition switch circuit
- Ignition switch
- ECU



Anyone ran into this problem? I hardly know anything about cars so I don't even know where to start... maybe my $800 Supra was $800 for a reason.. lol

Code 43 has nothing to do with your idle issues...

Code 43 can indicate an issue when the engine is cranking (which may explain your difficulties when starting the car) or it could appear simply because the car was push started (aka: pop started or dump started). It's not uncommon to see this code just because the car's been started by dumping the clutch while rolling.

Clean your ISCV. You haven't tried to clean the AFM have you? They break very easily. Air filter clean?


BTW - do NOT just make a new thread to post more info... it makes it hard for others to follow and makes it hard for others to find answers to past problems when searching the board. I'm going to merge this with your other thread.

Sorry about that, didn't think about it not making it easier to help solve the problem.

Thats good to hear because the car was clutch started the other day..

Is the part # for the ISCV 22270-43010.. if so I know where it is and can take it off. I looked at one of the links you posted about removing it. We listened for it to click but didn't hear anything. I don't know if it is good there is no click or bad.. like I said I am clueless about cars right now, this is the first car I have had to work on..

Also what is a AFM?

Yes, that's the part number for the ISCV (that's Idle Speed Control Valve). Here's the information on testing it: http://www.cygnusx1.net/Supra/Librar...ction=FI&P=106

AFM = a Toyota specific acronym for Air Flow Meter (a certain class of air measuring devices... no not all air measurement devices are an AFM)... You'll VERY commonly see people refer to them as MAF, although that is not accurate.. a MAF (Mass Air Flow Meter) is a term that's specific to another class of device, such as the GM "hotwire" MAF. It's not a huge deal, but it bugs me when a newbie posts back that they can't find the MAF in the repair manual... or better yet, because they bought an actual MAF and can't figure out who to hack the wiring.

There are two different types of air flow meter used in the 7M equipped MKIII... these are:
Karman Vortex (KVAFM) used in the 7M-GTE (NEVER try to clean one with any cleaning solution or solvents!!! These are optical devices and you'll just destroy it.)
Vane (VAFM) used in the 7M-GE. The Vane is a more durable device, but it doesn't age as gracefully due to the use of moving parts and it imposes a certain degree of restriction on the airflow.

Awesome. I will check it in the morning to see if it works or not.

Is the ISCV in Toyota Celica's as well? If it is broke than I don't want to have to buy it new when my local junk yard might have it! They don't have any Supra's though.

I know that the BVSV is in a Celica so I plan to get that tomorrow from U-Pull-It.


So if the ISCV clicks that means that it is working, if it doesn't than that means that it is broke or jammed correct? If it is jammed how do I fix it after it is removed?

Was looking under the hood this morning and noticed that 2 things weren't plugged in..

http://i23.photobucket.com/albums/b3...l/IMG_0515.jpg
http://i23.photobucket.com/albums/b3...l/IMG_0514.jpg

Don't know where they go to but Im planning on going to U-Pull-It tomorrow to get a BVSV out of a Celica.




EDIT:
Just got done checking the ISCV and after I shut off the car it clicks 4 times and than makes a FSSS sound. I am guessing that is good and that it is resetting itself. Tomorrow I'm hoping to get a BVSV and see if that fixes it.. if not I guess that I will be checking hoses all day..

Those plugs you have in the picture may be for options your car doesnt have. Mine had those unpluged and didnt have the surging issue like yours does. The ISCV is a better bet for the problem, they arent a no fail part none of the parts on this car are no fail just replace it they arent too expensive. As for the FSSSS when you shut it off check your vacuum lines sounds like one is in the wrong place.

Damn... put a little more time into the sentences SD... not making a whole lot of sense there.


The black plug below the battery may be the connection for the small electric aux fan located beside the primary fan.

The white ones by the cruise control actuator appear to be for turbo functions... odd you'd have a GTE harness there though. One would go to the stock boost gauge sender and I cant recall where the other goes.... been a long day and my head's not entirely in the game.

The only other vehicle that I know of with a compatible ISCV is a 7M-GE equipped Cressida (looks kind of like a Camry).

BVSVs are very basic devices... as long as the threads are correct just about any BVSV off of a similar vintage Toyota should work just fine.

Weird.. the guy that I bought it from said that he did a rebuild on the engine but I still don't know why it would be there if it wasn't a turbo..

Anyways I plan on getting everything done tomorrow. Hopefully replacing the BVSV will do the trick. If not I will check all of the vacuum lines with Carb cleaner or whatever you use to check.

The only thing that doesn't make sense to me is that the car ONLY does it every once in a while. When I bought the car we drove it for 2-3 hours home and it drove just fine, I drove it all day the next day and it worked fine. Than the night after it drove with the revving, the next day it was gone. It revved up ALL day yesterday and I started it today and it ran just fine..

I don't see how if there is a problem that it just happens sometimes. You would figure it would effect it everytime.


I don't think that the ISCV is broke, I heard it click 4 times when I shut my engine off so I'm not going to replace it now unless I need to. I think that the FSSS sound was it resetting, but I'm not sure.. if that FSSS is from a vacuum leak than it should be easy to find.. I'll just need a partner to help listen for me while I shut it off or vice versa.

Update:

So today I checked more into the ISCV to make sure that it was working properly. Unplugging it and starting the engine made it idle at 2 rpm and when plugged back in it ran at 1 rpm so I know that it is working correctly.

We sprayed down the hoses and didn't notice any leaks, the idle never changed when spraying over them.. so now I am lost have no clue what could be going wrong.

The car ran fine today as well.

When the car is off does the vane in the AFM close all the way?

Does the throttle plate close all the way?

Have you checked the intake piping for cracks or holes?

Have you checked the timing?

Any error codes?


Sorry if you've already been asked and answered some of these... I just can't keep track of everyone's problems right now, so please just bear with me and repeat your answers.

BTW, it's 1,000 RPM, not 1 or 2. ;)