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Done a lot to try to fix it, car never seems to balance, on the wideband it reads 17 over and requires it to be 1500 rpm, or it reads 10 under and then chokes out shortly after.
Idle mixture screws doesn't seem to do squat. Recently got an electric choke, but it also doesn't change anything (when cold or fully warm.)
Fuel seems to be fine, gas is yellow in the carb, no specs of dust. Fuel pressure is a constant 5PSI right before the carb.
It's lately taken a complete **** though and won't idle at all, at first I thought it was my electric choke, but multimeter shows about 11.6-11.8V
Engine was rebuilt, but maybe I'm putting too much faith in the rebuild.
Car Specs:
12A
Edelbrock 1801, 500 CFM
holley blue FP
So youre seeing 17AFR at idle and 10AFR and under when? The wideband wont read unburnt fuel. It is possible you could be pig rich, which would explain the "lean condition" which is actually unburnt fuel from being too rich. Have you tried leaning it out?
Other than that, have you checked fuel filter?
Im not to familiar with this carb. Do they have a pilot jet? is it clogged?
I don't think it has a pilot jet, just primary and secondary with an accelerator pump, and it's not clogged. I dealt with a clogged carb with the nikki, so the fine rust dust and other signs don't exist in my current carb.
I didn't know about the pig rich theory so I'll try it out. It goes 10AFR and under when I hit the accelerator pedal to balance it out. Currently it won't idle after I changed the spark plugs ( 1 minute cranking while plugs are out to clear out the engine )
I tried to lean it all the way by setting the idle mixture screws completely tight and then a quarter loose.
It only ran at about 4-5k idle, and with the carb hat off, but after 3 seconds a puff of white smoke came out the carb and I stopped. You think the stock jets on the carb is just too big for a 12a? it was recommended but plenty of guys in these forums.
When you leaned it out, what were the AFRs? Did they change?
nah there was absolutely no results. Makes me conclude that the idle mixture screws isn't actually leaning it out.
On the idea that it's pig rich showing lean on the AFR, I'm assuming that my carb might be leaking somehow? When I received it in the box I didn't check to see if the jets were tight, could that be it?
something is wrong with your 02 sensor, or you have some big vacuum leak or misfires or something. these engines will not run if the AFR is really 17:1
Hey there guys, sorry for the late post but I wasn't joking about barely having time to work on it.
I found my problem to be around the throttle linkage / electric choke.
the linkage circled, is actually above (where the arrow is pointing)
Now, I adjusted the electric choke clockwise (to become much richer and have a lot more resistance.) but for some reason the car "resets" to completely open butterflies, causing my lean issue.
Is there any extra linkage accessory I am missing to make the butterfly close (not completely) while idle?
also, o2 sensor seems about correct, or at least now it is. The issue really is that on idle the choke flaps are just way too open, even when the engine is hot. I've set the choke dial to the richest setting, and it doesn't seem to keep it slightly close during idle once the choke is warmed up.
Without the choke, I used to have the choke flaps "fixed" to one setting during cold start and warm start, but the engine always ran at 1.8k rpm on idle because of that... hope to fixed it with this electric choke but it's either missing parts, or not plug in and play. Thinking of just deleting this brand new electric choke and reverting to the fixed choke flap
edit: also, exhaust becoming visibly red is a lean condition, correct?
07-27-16, 03:40 PM
