Re: Hesitant 1972 Bay

gareth edwards wrote:

"gareth edwards" <gareth.edwards100@xxxxxxxxxxxxxx> wrote in message news:WO6dnZFZ25lVMJzbnZ2dnUVZ8seinZ2d@xxxxxxxxx

"Speedy Jim" <volks@xxxxxxx> wrote in message news:tZhMh.10407$P47.1217@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx

gareth edwards wrote:


"gareth edwards" <gareth.edwards100@xxxxxxxxxxxxxx> wrote in message news:JtSdnQqde6Ec2Z3bnZ2dnUVZ8rOdnZ2d@xxxxxxxxx


"Speedy Jim" <volks@xxxxxxx> wrote in message news:S2XLh.5823$tv6.5445@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx


gareth edwards wrote:



Recently started having this problem with my Bay 1600cc. It is very hesitant at low revs, and even if I put my foot down or pump the throttle a bit too get some fuel in there, it still takes a little while to pick up. Once the revs pick up it pulls strongly. It needed a service anyway so I have given it the works : spark plugs, leads, dissy cap, rotor arm, fuel filter, air filter, oil change, timing. I have not yet done the valve clearances or points and condenser, that will be on the weekend.
Do you think this problem could be something to do with the carb? or something like a manifold air leak perhaps?
Like I said, if i put my foot down to give it a squirt of fuel, it still does not pick straight up.

Two major items:

carb accelerator pump jet.
Hard to check on a '72 since you can't look down the
carb throat. Might have to remove the carb.

manifold heat. The smaller pipe under the manifold.
After a 10 minute run, feel both ends of the small pipe.
Both ends should be hot enough to burn your fingers.
If only one end is hot, the heat is not working and
will cause major stumbling problems.

Timing, spark and vac leaks are also possible causes
but my money is on the first two.

Speedy Jim
http://www.nls.net/mp/volks/

"I have no use for a car which has more spark plugs than a cow has teats!"
Henry Ford, when advised that Chevrolet was introducing a 6-cylinder engine.

Cheers Speedy

Do you think it could be the pump jet? As if the engine is revving at say over 3000rpm, and I floor the throttle it picks up straight away so it *seems* like it is working, it is only at low revs there is the problem.

I did not think of the heat issue, it has certainly been cold here lately in sunny South Wales! Will check this as soon as I can.

Timing is spot on, and pretty sure spark is good. Will let you know what I find.

Thanks Jim



Have not had chance to give it a good run out and check the heat risers on the manifold yet, but I pulled the carb off and checked out the accelerator pump and this is working fine, a nice squirt of fuel coming out of it every time.

One other question, I adjusted the valve clearances today by setting the pulley to what I thought was the TDC mark, but now I am thinking that it may be the 5 degrees atdc mark. Will this make much difference to my valve clearances?

The cam lobe is quite broad at that point, so being off a few
degrees doesn't really matter.

Jim

Great, I didn't fancy doing them again. On cylinders 3 and 4 all the valves were very loose, about 10 or 12 thou! This was not helping the way the bus was driving either. I will hopefully get a chance to take it out tomorrow, and then I can see how it goes and then also check the heat risers.

Thanks again Jim


Checked the manifold heat today and the left hand side was very hot, the right hand side not so hot. Just warm really. So this is causing my manifold to ice up?
After adjusting the valves the other day the bus is driving slightly better, but how much of a hesitation will the 009 dissy cause?
Will replacing it with a vac advance dissy really make that much difference?

Could not see any obvious manifold leaks. I sprayed some wd40 on the rubber boots and could not spot anything bubbling away there.



If one side is warm, it's probably working a little bit.
The heat is not there to control carb icing; that's another issue.

With an 009, you have to accelerate "gradually". That's key.

Jim
.

Relevant Pages

  • Re: Hesitant 1972 Bay
    ... hesitant at low revs, and even if I put my foot down or pump the throttle a bit too get some fuel in there, it still takes a little while to pick up. ... Do you think this problem could be something to do with the carb? ... or something like a manifold air leak perhaps? ... manifold heat. ...
    (rec.autos.makers.vw.aircooled)
  • Re: Hesitant 1972 Bay
    ... plugs, leads, dissy cap, rotor arm, fuel filter, air filter, oil ... Do you think this problem could be something to do with the carb? ... or something like a manifold air leak perhaps? ... manifold heat. ...
    (rec.autos.makers.vw.aircooled)
  • Re: Hesitant 1972 Bay
    ... dissy cap, rotor arm, fuel filter, air filter, oil change, timing. ... something like a manifold air leak perhaps? ... carb accelerator pump jet. ... manifold heat. ...
    (rec.autos.makers.vw.aircooled)
  • Re: Hesitant 1972 Bay
    ... throttle a bit too get some fuel in there, ... Do you think this problem could be something to do with the carb? ... something like a manifold air leak perhaps? ... manifold heat. ...
    (rec.autos.makers.vw.aircooled)
  • Re: Hesitant 1972 Bay
    ... cap, rotor arm, fuel filter, air filter, oil change, timing. ... Do you think this problem could be something to do with the carb? ... carb accelerator pump jet. ... manifold heat. ...
    (rec.autos.makers.vw.aircooled)