hey guys I'm new to the forums and I am looking for some help. I got an 85 4runner that I can't seem to get to hold idle/ start. the car will crank but not start and if it does start it idle real low/rough, it will start if I put starter fluid in it but will die as soon as I take it away. if I try to give it any gas while it idles it immediately dies. I'm getting fuel all the way up to the cold start injector. I've replaced the fuel filter, fuel pressure regulator,spark plugs + wires, pcv valve. I was messing with these two adjustment screws and that how I was able to get it to idle, but dies when I give it gas

 

Well, the first screw you showed is to cause the engine to idle up a certain amount, set by the screw, when you crank the wheels all the way to the end of their travel, to help around a tight corner. For now, II suggest setting it about 1/2 way out, and leaving it for now. You can come back and work with it later, but for now, it's not really relevant. Just be sure it's not out so far it allows air to leak in around it. Even all the way down until it bottoms out is acceptable.. For now.

The second screw you show is actually the cover to idle speed adjustment screw, which is located under the one you showed. If you tightened it down, it may have pushed on the idle speed adjust screw, causing the idle to drop, or it may have sealed the idle speed adjustment screw, stopping air leaking past it, thus causing a lean condition. That;s what you need to focus on. Take the cover off completely, and then count the turns needed to tighten the idle speed adjustment screw down till it bottoms out. Not super tight, just until it stops. Once you know how far out it was, how any turn from bottom it was, take it all the way out, and inspect the o-ring on it. At least it should have one. I wager it's either dried out, damaged, broken, or missing. I suggest replacing it on GP. You can find o-rings that fit all over the place. Very common item.

Once you have a new, properly sized o-ring, on it, put it back in, and screw it all the way down, then back it out until it's at A) the place it was before, or B) the idle reaches 800 RPM, whichever comes first. The correct idle IS 800, set with an external tachometer. You can get one cheap from Harbor Freight, or most auto parts stores. Good item to have. Use it after replacing almost any ignition part, or when setting the timing, again, after replacing almost any ignition part. Distributor cap/rotor, Wires, anything. A little bit of Vaseline on the o-ring will help it seal better, and last longer. Good idea to use it. Just a very little bit on the actual rubber of the o-ring is a good idea, as long as it's not in contact with gasoline.

A decent timing light is also a requirement for working on the engine. Also available at Harbor Freight pretty cheap, or most auto parts stores. It's important to set the timing, or at least check it, regularly. It can change with wear of the timing chain, and so on. Setting the timing correctly requires setting the idle correctly as an initial step. Thus, you both a decent tach, and a decent timing light for just for normal maintenance.

I would also check the timing to see if it's related to you original difficulties.

Does any of this help at all?
Pat☺

 

Thanks for the insight Pat, it does make sense and I will try what you said when I get back to working on it. I had the car running and then I replaced the water pump, thermostat, radiator hoses and radiator. And once I went to start up is when I started to have the issue. I drove the car befor I did any work and drove it around the block and it drove fine and was idling good. And that’s when I started to throw some parts at it.

 

Something to check after replacing those parts: Make certain, absolutely certain, that the big tube going from the VAFM to the Throttle Body has NO air leaks. Especially check the two "corner taker" things at the ends, The ribbed, plastic parts at either end that allow the tube to take the corners to the parts it attaches to. An easy way to test is to get the engine idling, if you can, and spray carb cleaner or starter fluid all over those two areas. If the engine idles up when you do, you've got a leak. The parts are fairly available from Toyota suppliers, like Rock Auto, and so forth, if you do find a leak.

Another thing to look at is to make absolutely positive all the vacuum lines are back where they belong. I know from personal experience (ahem) how easy it is to misplace a vacuum line or two during an evolution like you had. I've replaced all those parts at one time or another on both my vehicles, so I know what is required. Heck, I replace my radiator hoses (all 3) every spring. I save the ones I remove and throw them in a box in the back, discarding what was already in my safety box (as I call it), just on the off-chance I have trouble with one of the new parts. And I have. Same for things like spark plugs distributor cap/rotor, etc, etc. Replace them once a year, save the old ones. That way, if something fails on me, I have a part readily available that's only a year old, at most. Saved my tail more than once! Cracked distributor caps from the manufacturer have nailed me a few times.

Anywho, I hope you find the trouble you're having, and that it's a fairly easy fix!
Pat☺

 

Hey guys, i am also new to this forum and to working on cars in general. I have a 1993 4runner that has recently started having this issue where it starts, idles really low, then stalls. It does it intermittently and i was even able to drive it all the way home yesterday and left it running for a while without the idle dropping below normal. Any ideas? thanks.

 

Does it seem to do the lo idle only when it's cold, maybe?
I mean the engine's cold. Not warmed up to operating temp, not necessarily cold as in "BRRRrrr! I need a jacket".
If so, there's a device called an Auxiliary Air Valve that may, possibly, be part of the trouble. The PDF for it is here: Aux Air Valve .
I think it may also be related to the cold start injector, or the coolant temperature sensor that controls it. I would check those out too.


Get yourself a copy of the FSM, even a PDF or on-line copy. It will give you all the help you need for How-To all this fun stuff
Get a few wrenches and screwdrivers, and dig in. Best way to learn.

Good luck to you!
Pat☺

 

It does it intermittently, i was even able to drive it home from the shop with no issues. i haven't tried to start it since but will this afternoon after work. Where do i get a copy of the FSM?

 

Well, you can get it PDF format HERE
Another one is HERE, but you'll have to get a login. I think it costs a few dollars, but once you download the manual you need, you can let you subscription lapse.

You can also get paper manuals. They cost a few bucks, generally, but once you have it on paper, you've got it, even if your PC crashes, the power goes out, or whatever. Just google you truck's year, make, model. IE 1993 Toyota 4Runner FSM.

Does this help?
Pat☺