Carb Tuning - Toyota Nation Forum : Toyota Car and Truck Forums

Hotwheelharmer · 04-08-2004, 07:58 AM

Well since I just got my Celica running the other day I am now in the process of tuning it right. However since this is my first carbed vehicle and I didn't learn jack shit about carbs in school I am kind of lost. I have a brand new Weber 38 Outlaw on it which came with instructions but Weber is a bunch of jack asses and can't make a decent instructions so I am kind of lost. So is there anyone that can help me tune this thing? The problems I am having is I can't get the idle lower then 1300 RPM(need it at about 700). No matter where I set the idle mixture screws the RPM's wont change at all. Once I start driving the car the idle will jump up to 2K RPM. Can anyone help me out? And it isn't a vacuum leak because I checked that. The only thing I can really think of is since I removed a lot of the vacuum lines(there are a ton on a 22R) that maybe I have one of the lines that I kept in the wrong place but I don't know maybe it is just my jets I don't know.

alltrac165 · 04-08-2004, 12:09 PM

Idle speed is not set by the mixture screw. There should be another screw that goes up against the throttle plate cam either on the same side as the throttle cable or on the opposite end of the shaft. Idle speed can be affected a little by the mixture screw, but that's not how you set it. After you get the speed set, then go back to the idle mixture screw and adjust it back into the carb until you start to lose rpm then back out till the rpms come back. Then you get to start messing with the jets.
Oh yeah, go back over the engine and make sure you don't have any vacuum leaks as this will drive you friggin crazy trying to tune the carb. Be ABSOLUTELY sure you have all the vacuum lines routed properly or capped if they are no longer necessary.

Hotwheelharmer · 04-08-2004, 03:33 PM

I know you don't set the idle by the mixture screws. What I am saying is I have more then one problem with the carb. The idle screw is not touching the cam and the lowest idle I can get is 1200. I got the mixture screw problem fixed which was just put an exhaust on it. It helps if you have back pressure :-).

alltrac165 · 04-08-2004, 11:12 PM

in that case, look for leaks. Is the throttle plate really closed all the way? Any hoses to the wrong place? Sumptin not right. How about timing? Ignition timing too advanced?

Hotwheelharmer · 04-09-2004, 01:49 PM

I got it running right. I just have to not be a retard. The idle only needs to be under the 1100 under light load so I Got it. Got it tuned right but man Webers are a bitch to keep tuned right.