I put a weber two barrel on about a week ago, when I turn the truck off I get spudder and backfire. Is this a timming issue or a simple carb adjustment? Really buggin me! Can someone give meany tips to get this takein care of? Thanks in advance. Love this site!

This is a typical carb issue. The weber is a little over jetted for our 2.6L and most people jet the carb down. use the search tool for weber. the guys here gave me some good tips on how to tune the weber. your idle screw will not be turned out much at all. probably 3\4 to 1.5 turns. Is your carb new? what model is it? 32\36; 34, 38?

yes sir it is a new carburetor I believe it's a 34 cm. I nm not good with carbs. The instruction manual said bolt it on and go, yea rite! I will go find the box and let you know for sure what size.

cant find the box but I'm 100 percent is a 34. Is there to much gas being left in the carb? The raider goes thru gas like a v8. Need to save all the gas I can lol.

What is happening is called dieseling. The motor continues to run, despite that the ignition is turned off.

This is because the spark plugs, exhaust valves and general combustion chamber are hot enough that the fuel ignites on its own.

Since the carb supplies fuel as long as air is passing through it, it just continues to do its job.

The factories did a couple of things to prevent this.

1: Added a solenoid to kill the idle fuel.
2: In some cases added solenoid to close the throttle when the ignition is off.

What can you do?

The fuel kill circuit is not a DIY mod and has to be designed into the carb.

A solenoid can be adapted from cars that used a Weber knockoff. A Vega or a Pinto might be good donors.

Weber might have one as an option.

You can also drop your idle speed, lower is better when it comes to dieseling. More initial advance on the ignition timing will reduce the amount you need to open the throttle to get it to hold a certain speed. Most motors will take an extra 5? advance without any issues.

Make sure your motor is in good tune. Encrusted plugs and chamber deposits dont help.

Make sure the idle mixture is properly set.

If your getting really bad fuel economy, trace the issue down as well. Is your dist advance mechanism working correctly? The mechanical advance gets gummed up over time and the vacuum diaphragm gets torn.

Also make sure you have the dist advance chamber hooked to the ported vacuum line on the carb.

Start with idles speed and mixture. I would shoot for 750 RPM.

Kevin

Wow. Think I might be in over my head. Im fimilar with the idle adjust, and the mixture adjustment. Gentleman said earlier the idle screw should only be turned out bout 3/4 turn. What about the mixture screw? I put a new vac advance bout a month ago. ( 125 bucks! ) rite now the truck starts rough but one shot to the peddle and it settles down. When I had the elec choke hooked up it would always idle high ( at least 2000 ) when I clutched it. So I disconnected it. Its ideling at about 1 or a touch more. Im sure my timing is off as well. Tips?? I can use the most basic helpyou can offer. The truck runs good other than the spudder and ocassonial back fire when I shut it down.

Turn the idle down to somthing under 1000 ( 750-800)... Adjust the mixture screw to get a smooth idle when warm.

web page

This should be the instructions for your carb.

thank you very much for the site link. I will let you know the results.

to clarify, I was refering to the idle mixture screw being 3\4 to 1.5 turns out and not the trottle positioning screw. sorry for the confussion.

I replaced the stock Mikuni with a Weber 32/36, and there's a thread on here somewhere with more details. But one thing you might have to do is add a return spring, to make sure the idle arm fully returns.

When I first installed the Weber, I followed the instructions to adjust the fuel/air screw (basically turn it in until the engine almost dies, then back it out a quarter turn at a time until the engine starts to run rough, then turn it back a quarter to half turn). Once that's done, setting the idle screw is pretty easy, but the Weber is very sensitive to where you set the idle. Don't go any higher than 700-750 rpms, which is lower than the factory recommended setting of 800, and mine actually likes the 600 rpm range.

After I set the fuel/air and idle set screws, I found that the carb wasn't fully "closing" which was resulting in my idle staying around 1000 rpms, and dieseling when I turned it off. When it was idling high, I'd tap the gas pedal, and it would drop to where I had set it originally. After looking at how the carb was operating, I figured I'd add a return spring to "help" the idle fully close, and it's run fine ever since.

I posted some pics in one of the Weber carb threads about this spring that I installed, so I'd do a search and see if you can find it.

http://www.4x4wire.com/forums/showf...;amp;page=0&fpart=4&vc=1

Good luck!