Need carb help

[walkersimpson]

Got my engine and transmission all switched out and trying to get her to pass smog ran into a problem my idle jet is pumping to much fuel can anyone tell me how to adjust the idle jet would be greatly appreciate really need her running right start school tomorrow and unless I fix it, will not have a car unless I fix it and know you guys always help me out thanks guys

[Petros]

it is not likely the idle jet, that adjustment is set and sealed at the factory and usually does not need adjustment. there is no way for it to put more fuel into the carb than it should, it can only get plugged up and put out less. Unless you have a rebuilt carb and someone removed the seal when they did it, and badly messed up the idle jet adjustment.

The more likely cause is the Auxilary Acceleration Pump (the AAP). It is supposed to operate only when cold and puts extra fuel into the carb during acceleration. it is a diaphragm on the right front coner of the carb, and it often will get worn out and leak fuel into the vac line, where it makes its way into the intake manifold. find it and un plug the vac line, if it is full of fuel you can cap it off and likely pass the emissions test. It is not necessary for normal operation, but only helps a little when the car is stone cold on first startup.

It is easy to replace without removing the carb if you wan to fix it, but you can get by without it, just cap off both ends of the vac port and line.

do a search for pictures of the AAP on this forum to help you locate it. good luck.

[walkersimpson]

Thanks petros will try that out have a manual so will see if that work will let you know thank you for all your help you guys are great and will post some pictures of her when she is all done and running like a dream

[walkersimpson]

New problem it's idling better now but can't get it below 1000 rpm idle screw all the way out have no idea what it could be anything to try would help have a Manual I can reference to for help but anything would help thanks

[dlb]

couple ideas.

1) check the fast idle setting as well as the regular idle.

2) check your ignition timing. be sure to disconnect and plug the vac advance hoses. with those disconnected, the timing should be 5* BTDC but you can set it to 10* BTDC for slightly better power.

3) check for vacuum leaks. make sure all the hoses are connected properly according to the sticker on the underside of your hood.

4) test all the vacuum diaphragms by putting a clean hose on each diaphragm and sucking. you should not be able to suck air through. if you cannot suck air through, that diaphragm is good. if you can suck air through, the diaphragm is ruptured and you must disconnect and plug the hose that goes to it until you can replace that component. there are diaphragms for the vac advance, choke opener, choke breaker, EGR, and throttle positioner. i think that's all of them.

5) set the throttle positioner (aka TP) following the steps from the FSM.

could be other things but those are the first things that come to mind.

*EDIT* for passing smog, be sure to set the ignition timing to 5* BTDC. you can reset it afterward if you like.

[walkersimpson]

Vacuum hoses all good don't have a timing light but was checked in the last few days. So I switched back to my other carb and it has the same problem won't idle below 1000 but its worse on this one it idles at its lowest 1500. When I look in the primary barrel I can see a lot of fuel coming out the small ventury does anyone know what I need to adjust to lean that out because its running really rich any other suggestions would help

[dlb]

is there enough slack in the throttle cable? there should be lots.

besides that, still test the vac diaphragms on the vac advance cans (found on the bottom of the dizzy). if the upper can is ruptured, it will be a vac leak at idle which would contribute to a high idle. i also still suggest going through everything mentioned here since both carbs could have the same problem, or different problems that manifest similarly.

[walkersimpson]

Checked all the diaframs and they are all good I think I'm going to bring it to the shop just because I have been so frustrated and feel I'm going to screw more up and I'm back in school so I think the shop is my option right now and I'm fine with that will put more time into it once it passes smog to get it to run properly and how I want it to thanks for all your help guys

[TominMO]

Here is a good page for carb books. It is nice to know how they work.
http://www.amazon.com/Carburetor-Perfor ... ird+elston

[Petros]

I know how frustrating it can be working on a complex system for which you are not familar. It is easy to give up, but I advise you not to give up so easy. Make sure the shop knows what to with a carb system!!! most mechanics were not even born when these cars were built, and will likely make a big mess of it for you, and charge you for it. Ask them questions about how familiar they are with your car, how much experience they have with carbonated engines (how many years, how many the work on each year, etc), and particularly with Toyotas carb engines. If they give vague or evasive answers WALK AWAY! Do not trust them, they will not want to take the time to learn the system, and will replace something and charge you for it, and not fix the problem. You will waste your money and by the time you are done fighting over it with them you could have fixed it yourself for next to nothing in cost and less time that to deal with shop.

It is not really as difficult as you might think to sore it out yourself. You have to get past the intimation of the system and just work your way down the troubleshooting guild in the FSM, and than run the functional tests one at a time. Going though each system one at a time, and test and check operation of each, should not take more than an hour.

[walkersimpson]

thank you petros that is exactly what i needed to hear i am going to go through it tomorrow and figure it out while learning much more about my car thank you i need to know it anyways so it is a plus no matter what. the thing that bothered me most was how fast the change happened just took the carb off reset the idlemixture took a peak in the carb to make sure it was clean and all went to hell even with a carb i didnt mess with so something weird is going on will figure it out tomorrow thanks petros i needed to hear that i get it done and get some pictures up soon

[walkersimpson]

I did what I could the manual has no real walk through on work on the carb mainly the simple stuff I know how to do and the. It goes through rebuilding carbs so I spent another 3 hour working in it opened her up and cleaned some stuff but she is still idling to high checked the vacuumed hoses again and again but what I need are a second set of eyes some fresh eyes to look at my carb. I have a question should I be able to see a good amount of fuel going into the carb? When adjusting the mixture should I hear or see a difference in running (I have seen no difference idles the same). Really I don't know how many more times I can go over the carb. One I need transportation so I can get to school and home 14 mile commute and this carb is the only thing stopping me I have no idea I have tryed doing everything everyone had recommended and am still having trouble have any of you had a problem with high idle or other suggestions I should go over before finding a good carb guy thanks

[Mark]

1000 rpm isn't too bad. My auto is supposed to idle at 800. I originally couldn't bring the idle down to within spec on my current car. As some have suggested, it turned out to be a vacuum leak. I had several: AAP diaphragm (I capped it off since I don't need it), EGR vacuum modulator diaphragm (replaced with one from a scrap yard) and choke-opener diaphragm (replaced with one off a spare carb that came with the vehicle).
Every noticeable vacuum leak I've had has always been a diaphragm.

[Mark]

Also when you removed the carb, did you tighten it down enough when you replaced it? Maybe there's a vacuum leak at the gasket.
I assume you checked the idle speed when the engine was warm and the choke was fully open? Did you verify that the throttle was fully closed?

[ARCHINSTL]

It's simple, but overlooked (I did with my reman Aisan back in 2005). It - and the Weber - needs more throttle cable slack than you might think.
Remove the cable and try adjusting the idle screw down to the OE 800 RPM. Then reconnect the cable, making sure it has a direct path to the bell crank.
While it is loose, this would be a good time to dribble a thin oil down the inside of the sheath (make sure you put a rag where it exits the firewall on the interior...).
Tom M.