rolltide81

hey yall my truck is a 1980 4x4 lifted flat bed all that jazz..but my problem is that when you get below 45mph it sputters and backfires.and the motor just cuts out..also at a stop light you have to hold the clutch brake and give it gas constantly so it wont die.it will die goin below 20mph th motor just sputters and dies.im just lookin for a starting point as im not super familiar with Toyotas .this problem has been going on for awhile now and its slowly getting worse.does fine at high rpm but idles real low.can anyone lemme know how to adjust the carb on one of these 20re motors or lemme know what yall think the problem might be. I heard fuel cut solenoid but I checked that and it seems to be okay.im prayin its not electrical and just a improperly adjusted carb or something mechanical.thanks

cman1

iTrader: (1)

plugs,cap,rotor,wires.

Smilemon

What tools do you have available, and what is your comfort level with working on cars?

Plugs, cap, rotor, wires, and maybe air filter, would be the first thing I did. Then move on to timing and idle speed adjustment.

rolltide81

done all that put in a new distributor ..I got a boat load of tools and am comfortable workin on vehicales im just new to the Toyota 4x4 thing my wife had to get one for her own muddin truck so now I gotta try to figure this thing out LIL different from the chevys haha.any advice on where to start is more than welcoime

rolltide81

the thing is its been doing this for along time but she used to just work down in town but now she has to drive further and its becoming a problem.ive messed with the carb but im not 100% on what all the different screw on that thing are for.ive done the distributor ..I tweaked the timeing on it and it ran and idled a lot better but after a couple days the sputtering and dieing at low rpms came back and will not idle in gear or out if you don't give it gas.i looked on line and a lot of people said they had similar problems because of a fuel cut solenoid .I tested that and it clicked like it should ..could it be the electrical going to the solenoid because I tested it by putin 12v to it and bypassing the current electrical.im kinda assumeing its a carb problem but theres a lot I don't know about these 20re motors.

cman1

iTrader: (1)

fuel filter.do you have the stock carb or a weber?

RobotMoose

iTrader: (1)

Sounds like a vacuum leak, or timing.
To be honest, the electrics are so simple on these engines, it really can't be too tough to fix them; generally the fuel cut solenoid, as you've mentioned, is the culprit with electrical trouble. The electrical is far more complicated when it comes to the body side than the engine side.
How is it on power?

rolltide81

pretty good on power that's about the only time it does well is when your goin over 50 is there a way I can check and see if the fuel cut solenoid is getting power ?I have a stock carb id like to see if I could adjust the idle ..what exactly is timeing set at I remember doing it and it ran better but now I forgot .so yall think it might be fuel cut or vacuum not the carb or maybe electrical?if theres anything I could test

rolltide81

well I think my problems are more serious I went out there to mess with it and now it will not stay running at all..i had to put a block on the pedal long enough for me to run around to give it gas .and then I hear a clanking inside the motor real bad .like a hunk of metal in a dryer .so bent rod busted piston?you cant hear it when driving its got no muffler and the exhaust is super loud because its cut real short .what would be best in this situation pulling the oil pan or intake?i cant take it nowhere it wont stay running.

RobotMoose

iTrader: (1)

Pull the valve cover, look at the timing chain and guides, check to see if any valves are stuck.
Bent rods are rare with these trucks, they're built like diesel components: thick, beefy, overbuilt. When they fail they usually just let go and fly out the side of the block. Busted piston would probably just seize the rotating assembly or go through the head.

It's hard to diagnose remotely, and any number of problems could be the cause, but my gut's saying it's timing related.

Smilemon

Does it sound like this?

perushing

To me it sounds like your air-fuel mixture is off a bit.. There's a little window on the front of the Aisin carb and the gas in it should be just up to the middle.. Other than that, I would look into checking your fast/slow idle screws and your mixture screw... I will see if I can get some literature on the Aisin carb for you.. That's what it sounds like to me.

perushing

Here I have a manual that has walked me through a lot of maintenance on my own pickup. If you're not familiar with Toyotas, this should help you out a lot.. Page 119 and 120 walk you through tuning your carburetor. If you give me your email address in a private message, I will be more than happy to send it to you. It is a .pdf file. It covers everything from how often to check your fluids to doing compression tests and even helped with rebuilding the motor..

Philip

rolltide81

hey I don't know how to private message my email is erich545@comcast.net ...thanks hopefully itll be pretty helpful. my motor says 20r on it most things online are for 22r or re but while I was looking up timing I saw that the 20r has a different looking timing mark deal my numbers for mine looked more like the 22r.i took both vacuum lines off the distributor and plugged them and put it about 13degrees BTDC and adjusted the screw on the back lower part of the carb on the pass. side which seemed to increase the idle enough for it to stay running.the tach in the truck says its a 1500 at idle but im gonna hook up a timing light with a built in tach to see if this is true because at 900rpmit wont stay running.also when I plug the vacc.lines back into the distributor there is no difference

perushing

I had to run mine a little above 900 for it to run smoothly as well.. A big difference for me was where the distributor was bolted on too... If you're off just one tooth or more your idle is gonna be either way too high or not enough to keep it going. So you may look at that also.

rolltide81

ok did the timing and adjusted the carb a little got it to run with a smooth idle at 1100 but it will run good at idle then every minute or so the rpms will drop to about 700 and it will sound like its gonna die then they will jump right back up and it will idle smooth again this goes on and on while its just sittin and runnin...vacuum ?

Smilemon

Man... almost sounds like a fuel supply issue. You sure your pump is working well?

cman1

iTrader: (1)

fuel filter.....

Smilemon

Yeah, probably worth blowing out all the lines and replacing the filter before he jumps straight to the pump.

rolltide81

hey I think I might have stumbled upon it.. there is a round thing on the carb apparently called a fast idle cam breaker it has a vacuum line going to it in a book it says to disconnect and plug this for setting idle speed screw ..well when I unplug it ,it runs fine it has vacuum to it but as soon as I plug it back in it the idle goes up and down .whiule it was unplugged I noticed fuel dripping from the port where the vacuum line plugs into .Im no expert but that don't seem good.could this fast idle cam breaker be broken clogged?