Troubled 1949 Pontiac

[katzenhammer]

A good friend of mine who is computerless is having some troubles with his 49 Pontiac The car has a running flat 6. So far the carb has been rebuilt, new points, plugs, wires, and so on. With the oil bath aircleaner on the engine was acting like it was getting "choked" out. This happened after the carb rebuild and having what we thought a "dialed in" carb. Without the oil bath on it runs fine but will not idle up smoothly to take off in first gear. It will cough and sputter and occasionally die. He has to wind the motor let the clutch out slow or it kills. Once the car is rolling it goes through the gears fine.

This weekend he is going to check the timing once again just to see if it held. I think he has a stretched timing chain but the motor idles at a constant RPM. There are no leaks on the carb. Could it be that it needs a new distributor? He is kinda at a loss of what to check next.

If he needs a distributor rebuild does anybody do this in Minnesota? or is this a Kanter specialty item?

Thanks for any advice in advance.

[Fat Hack]

Man, I love them old Poncho straight six and straight eight flatties! Just can't bust 'em! http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif

Anyhow...sounds like you may have a couple of things happening here.

For starters, too much oil in the air cleaner, or an old foam element? I'd replace it with a paper filter and different air cleaner anyway...or use a new, clean foam element without so much oil at least.

Next, double check for leaks around the carb base gasket.

Make sure your float level is right, and that the float isn't sinking or sticking.

Make sure the accelerator pump is working...look down the carb (with engine off!) and work the throttle. You should see/hear/smell a spray of fuel.

Adjust your idle mixture screw to see if you can smooth the transisiton from idle to acceleration.

Now...on to the ignition...

This may sound silly, but don't overlook the obvious. Check the spark plugs. I don't mean that as any sort of an insult, but too many times I've gone over to help someone figure out a tuning problem or driveability issue only to find old, half-fouled and/or improperly gapped plugs in the engine! Can't count the number of times that anew set of plugs solved the problem!

If the plugs look good, inspect your point contacts for pitting and replace if neccessary. Then check your dwell with a meter. I don't recall the spec for that engine off the top of my head, but look it up and make sure it's within the given range.

Remember...set your dwell BEFORE you make any timing adjustments. Why? (all together now!) "Because dwell affects timing, but timing does not affect dwell". Seen alot of "pros" goof that one up!

The distributor should only need to be "rebuilt" if the bushings are bad and the shaft fit is too sloppy. This will cause "spark scatter" under the cap. Really, new points and condensor are all you should need if the shaft tolerances are good and the rubbing block isn't eccessively worn.

Try bumping the timing up a degree or two if you can. Those engines used very modest compression, and an extra little "oomph" in the form of a little spark advance might help it out!

Just a couple thoughts to get the ball rolling...

[katzenhammer]

Yeah Hack it is a great car. Unfortunately it has this damn gremlin that won't go away. It may be a carb issue since it has been rebuilt twice. The first time he and a buddy did it and ended up with a fist full of "spare parts." The most recent time was actually from a highly reccomended shop. I am almost willing to bet that it is better now than before. I will however mention to them to spray some starting fluid around the carb.

He has pretty much dealt with the obvious as far as ignition is concerned. many of the simple parts-Plugs, Wires, Points, are new. I doubt they have been fouled the car has been driven at most 30 miles this summer since their replacement.

I know when he timed it he just used a light NO Dwell meter. Maybe that is something that needs to be takin into consideration. Thanks for your help nonetheless. hopefully it is a simple fix.

Justin

[LiL' NiCk]

As already mentioned, it could be accelarator pump. I had a similar "choking" problem last year w/ my '52, I can to find that it was "choking" for fuel - My problem was the fuel pump & line was gunked up, This also some thing to consider. And hope everthing is goin good for ya in the studio, lator nick