I have an 86 Toyota PU with a 22r. It has california emissions. I have a couple of problems. I just rebuilt the engine and put it in the truck. It runs great except that it does not want to idle. It accelerates and runs fine on the road, however if I slow down suddenly or put the clutch in and let the engine idle down, I can hear it start the pop and backfire a little and then the engine will die. It starts right up again but it is a constant problem. If I give it a little gas when I am slowing down (clutch in), it will start to idle, but real rough (500 rpms). I cannot find a vaccuum leak, however on the passenger side of the truck is a switch that has two vaccum line ports on it. One of the ports has a line that runs to what my chiltons manual refers to as a "throttle positioner". There is another place for a line on the switch on the firewall, however, I don't remember taking a line off of it, and my vacuum diagrahm doesn't even show that particular switch. The switch I am talking about has an electrical pigtail that plugs into it and a small balck plastic "filter" on it. The switch is mounted to the base of the EBCV (chiltons term not mine), it is not the VSV (another chiltons term) Anyone have any idea what that is and where does the other line run to? I have looked all over and can not find any other place for a line. As per the diagram all my other lines are correct. Sorry aobut the abreviations, they came off of my vacuum diagram, however I could not find what they stood for.

Also, the timing on this thing is got my wondering. I set the timing at zero with a friend giving it a little gas to keep it at 700 rpms with the vaccum lines on the distributor disconnected and plugged. I then reconnected the lines and for the grins of it looked at the timing. It was exactly the same. I gave it a little gas and it advanced exactly like it did when the lines were disconnected. This seems strange to me. It seems that the vaccum advance was not working. How would I test the vacuum advance and how would that be corrected? I have the feeling that what ever it is, is the heart of my idle problem. As usual thanks in advance.

I'm not sure about the vacuum advance, but as far as your idle goes mine did the same thing. Finally figured out that it was the idle cut solenoid(sp). I just cut the wires to it and left it in the carb, gets a little worse gas mileage but it runs. Really easy to find too, follow the wires going to the carb, there should be 4 of them, 2 go to the choke and the other 2 go to the idle cut solenoid(sp), I was told by a carb shop that if you just cut it, it won't mess anything else up, just knock the mpgs down a little.....you do need to leave it in there however, to plug the hole. If you're a little better in the $$$ department then me then just replace the thing, but I'd try this before I started buying parts.

Good luck!

Well before you go cutting anything..

The wiring harness for the carb (four wires as mentioned) has a little green plug. Unplug it. Apply 12v to the power source of the idle solenoid (wire leading to the solenoid that isn't black) and ground out the 2nd black wire. You should hear a click. If you don't the solenoid is bad and needs to be replaced.

If you hear a click, then thats not the cause. Any difference between idling/not idling when engines warm or cold? Even if no, your choke could be out of adjusment and cause this.

Have you played with any of the carb's screws? Test the solenoid and post back.. I'll go into further detail about some other things to try.

Good luck!

Scerb

Oh, and about your timing.. I'm pretty sure mine acts in a similar manor.. probably because there isn't much vacum while engines not under load. Apply a load and the vacum advance should do its thing <img src="/forums/images/graemlins/cyclops.gif" alt="" />

-Scerb

Ok, thanks for the reply, I will test the solenoid and go from there. I would rather keep my engine as fuel efficient as possible with gas being as expensive as it is right now.

As far as the timing, I guess what concerns me the most is the fact that all my manuals stress that you have to disconnect those vacuum lines when doing the ignition timing. If the engine is not under that much load at idle and the vacuum advance is not even effected at that point, then what is the purpose of disconnecting them?

I have not messed with any of the carb screws. It was running OK, before I rebuilt the engine. When it is cold, (lower 40's) the engine will actually idle just fine for a minute or two until the choke opens up. I have only put about 150 miles on the rebuild (back and forth to work). I haven't calculated my mileage yet however I seem to be getting about the same as before I rebuilt the motor (19-20 mpg).

Like I said before, this idle thing is driving me nuts.
One thing to ponder, I noticed on 4crawlers website, he mentioned a "dash pot". I thought this was just an EFI thing until I was reading on pirate 4x4 that they also came on carbs in certain years. I havn't gone out and looked at mine since I read about it, however that may be something to look at too. 4crawlers website shows a picture of the EFI setup however I am wondering if the one on the carb looks the same. My manual doesn't mention a dashpot.
Here is the link, it may explain it a little better.

http://www.pirate4x4.com/forum/showthread.php?t=412050

At idle when you connect the hoses, the timing should advance by 7-9 deg. If it doesn't then either the hoses are bad or the vacuum advance controller is bad. You can test it by removing it from the distributor and applying vacuum to either of the ports. The arm should move when you apply the vacuum. If it doesn't move or the unit won't hold the vacuum, then it's bad.

BTW, Toyota is proud of those. About $140 list. <img src="/forums/images/graemlins/frown.gif" alt="" />

Bob

please, Toyota is proud of ALL of their parts. <img src="/forums/images/graemlins/barf.gif" alt="" />

NAPA's was about $90, plus core return. If you wind up going this route, make SURE you get all the stuff you need on the new distributor from the old one, like the gasket seal and the like. Give 'em a good looking over before handing the core back across the counter.

You can find a few on ebay as well; have the seller verify the part number for you.

I had an 86 that did this. I found a diaphragm in the carb had worn a pinhole sized hole in itself through use. It happened right around 250,000. You might want to check those. It's on the side and does not require a carb rebuild. Once I found the problem it was easy to fix.