Anybody solve the "lurching," on acceleration with

[PeterVarga]

Well, Squeeky passed smog so that means the jets in the Weber DGV

are supposed to be proper. 140 Main, 170 Air Corrector. She

runs smooth but after warm-up each time I acelerate from STOP

there is a lunging or lurching until she gets to about 1500-2000 rpm.

When the choke is still active (before it is warm) there is no problem.

Perfect smooth acceleration. When I first bought her there was no

problem. Somehow it crept in when someone adjusted something.

Does the fact that it runs fine when the choke is on mean it gets

overly lean when warm. How to correct? Larger main jets, smaller

air correctors, valve adjustment. Its got to be something relatively

simple since it was working fine a couple of years ago.

Any suggestions. I'll bet this is a classic carb trouble shoot for

an experienced old timer.

Thanks

[themoose]

Check your timing and your accelerator pump jet.

[doug73cs]

Bear in mind that I'm coming from 38/38 downdrafts not 32/36 but this sounds like the idle circuit is too lean and the initial throttle response may be influenced by the idle circuit in normal driving inputs (versus foot to the floor burn outs).

Read the following (if you haven't already) and try going one size larger idle jets.

http://www.redlineweber.com/html/Tech/carburetor_set_up_and_lean_best_.htm

Good luck with it.

[Guest Anonymous]

too lean at idle. Try larger idle jet.

[PeterVarga]

thanks.....I'll look at the idle circuit.

[PeterVarga]

...that was it. I looked at the Primary idel jet.

It was cracked! Next step, get on the internet

and order a replacement! Thanks again.

[PeterVarga]

November 1, 2007

Went to the candy store and purchased stock primary and

secondary idle jets. Installed properly. Slight improvement

in lurching on acceleration at low RPM. Did not solve issue

on this try.

Next, reset valves to spec. They may be out. Since it seems

that the engine torque is less than needed at the low end I'll

try to peak the power output given this stock CA engine. It

does seem that one cylinder is pulling stronger than the others.

If I can correct something in the others that may be the cure.