Having some need to reply to a subject that I really know nothing about, but
that has never stopped me before.
I once had a motorcycle do about the same thing. It would run rough and then
fine. Then it would run fine on idle and really nasty when reved but not untill
the main jet was really cooking, it would rev to about 6,000rpm and then shut
down, then it would come back on at around idle. It didn't make sense at all.
It didn't act plugged up. Inspection of the float bowl, and the rest of the
fuel system showed everything was fine. Finally I pulled the carb to clean it.
A flake of rust had caught itself inside the jet. The flake would act as a
valve shutting off the flow of fuel at a certian flow rate. Point is, sometimes
something small can do something wacky, I would take the offending carb apart,
clean it and put it back together. Most of our cars are old enough that stuff
gets into the carbs.
Thomas Carney wrote:
> Some of you may remember this past summer my GT6 ran really bad after I
> had gotten some gas. Well I never did figure out what it was and a few days
> before I left for school I had the mechanic do the work on it. He told me
> all he did was retune the carbs. The other night I went to get some food
> and it happened again!!! This time the car started and ran fine, I get to
> the drive thru window, get my food, go to pull out and it begins all over
> again and I didn't even turn off the car this time. Seems that all of a
> sudden the Carbs decide to run out of sync. Noteably the front carb. The
> change in performance is not too noticeable, but it sounds like it is
> misfiring when the gas is applying, a very uneven note coming out of the
> exaust.
> Here is what I have checked so far, but I am at a loss:
>
> Car dies if I pull one of the plug wires to the 3 rear cylinders.
> Car does nothing if I pull all 3 the front (well it did shock me good)until
> I start to give it gas, then there is a noticeable drop when I pull one
> plug.
> At idle i can remove the top of the carb and engine runs same as when on.
> Looking down into the jet area also shows that there is no gas coming out at
> idle. Gas does come up if I rev it high enough.
> Floats are not sticking and niether is the needle valve. Piston moves
> freely as well.
> So I am pretty sure the front carb is the culprit(as was last time)
>
> I have gotten it to run a little better by openeing the front butterfly more
> and enriching the mixture a tad.
>
> Any ideas how it drop out of sync like this, I hope I can get it running
> right before my trip home.
> Any other suggestions i should try out?
> Thanx
> Tom
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