tgreco

First off, I apologize for yet another Weber post, but I have searched and can not find a solution to the problem.

I just installed a trail-gear header on my '81 22R and completed the de-smogging, including the removal of the air injection system and EGR. I blocked off both ports on the block. I am currently running a Weber 32/36 and I have checked for vacuum leaks. After I got the header and exhaust finished, I now have carb issues where before I didn't. As I did the de-smog and header at the same time, I'm not sure which might be the problem.

The symptoms seem to be too much air. I can partially cover the carb intake with my hand and the idle smooths out, but uncovered it runs really rough. I had to crank up the idle screw just to get it to run without stalling every time I pushed in the clutch. The air/fuel screw does nothing to change the running condition. I disassembled the carb to check that everything was working correctly and could not find any noticeable problems. One thing that seems odd is that the butterflies will not close entirely at idle which may be allowing too much air. It also wants to backfire while coasting in gear - timing?

Any input on an approach to fixing this issue would be much appreciated. I live in GA ~ 900ft and wonder if I may need to re-jet given the change in backpressure.

caboussleman

A weber 32/36 flows 325 cfm and a stock carb flows 326 cfm. So I think that your jetting is off i think you need to get bigger jets in the carb. When you partially cover the carb your changing the fuel air mixture making it richer. So by the sounds of it you need to adjust the jetting.

tgreco

Would the header/exhaust change increase air flow or was it the desmog? It makes sense that air flow would increase but just want to make sure before I start throwing parts at it.

caboussleman

yeah you changed the air flow by adding the header and de-smogging it. so youll have to add more fuel to compensate for it.

JonnyBoy

Yeah, cabousselman more than likely has it right. I'm at 4,000' elevation, and had to go with richer jets, when it seems lots of people with unmodified 22r's don't, even at sea level. I have some brand of header and have desmogged my '83 as well.

tgreco

Just to finish the thread in case anyone else has this issue:

I called LC Enginerring to confirm the need to rejet and they said it was likely another issue: vacuum leak likely - this was not the issue.

During the desmog and header install, I also installed an idle cut-off solenoid. I started thinking that since this replaced the primary idle jet that it may be the root of the problem. So, I replaced the solenoid with the old primary idle jet and it fixed my idle issues. The idle cut-off solenoid is a size 60 while the original jet is imprinted with an 09. I'm not quite sure what this means as far as jet sizing but I did find some useful information from the link below.

http://www.racetep.com/webjettune.html

thanks for the responses.

JonnyBoy

Well if you start having dieseling problems, you should put that idle cut solenoid back on. The jets can be removed from the solenoid or the regular screw and changed.

On 2nd thought, I think you removed a 60 jet for another 60 jet. One was just stamped upside down. Did you have constant 12v power to the solenoid?

tgreco

Well I officially feed like a dumb-a#@ now re 09 is 60 upside down.

I will check the voltage to the solenoid as it does diesel on shutoff. As the ability to read obviously evades me, I may have to live with dieseling in lieu of diagnosing an electrical issue.

bytal

Would desmog and a header allow it to breathe that much better that it would throw the mix off enough that it can't even be adjusted with the mix screw? Assuming the weber has a mix screw.

tgreco

I did a little more diagnosing:

No power to the idle cut off solenoid so that was likely why it was stumbling at idle.

I also had a vacuum leak on the brake booster hose.

To address the previous comment, I wonder if removing the air injection tubes affected the characteristics of the intake as now I don't have hot exhaust being recirculated to the intake.

Overall I've got my idle dialed in with no dieseling on shut off and no cutoff solenoid. I do think I need to rejet as I have slight engine pinging under acceleration.

Thanks for the help.