Jim Saraceno Posted June 11, 2011 Report Share Posted June 11, 2011 This has happened to me three times. I was driving along, everything is fine. I stop for a minute, twice to change drivers so I don't think I turned the engine off and once to make a quick "pit stop". We start up the car, start heading down the road, then about a minute later the car "hiccups". It kind of bucks two or three times as if it is not getting enough fuel. Then everything is fine and we just keep on going like nothing ever happened. Anyone have any ideas as to what could cause that? Quote Link to comment Share on other sites More sharing options...
hillbilly4008 Posted June 11, 2011 Report Share Posted June 11, 2011 I have no clue, but I am having the same issue. Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted June 12, 2011 Report Share Posted June 12, 2011 This has happened to me three times. I was driving along, everything is fine. I stop for a minute, twice to change drivers so I don't think I turned the engine off and once to make a quick "pit stop".We start up the car, start heading down the road, then about a minute later the car "hiccups". It kind of bucks two or three times as if it is not getting enough fuel. Then everything is fine and we just keep on going like nothing ever happened. Anyone have any ideas as to what could cause that? Heat Riser? Fuel mixture, not quite to the old girls liking till she warms up a bit. Could it possibly a shortage of fuel delivery momentarily. This crappy ethanol blended gas, maybe has something to do with that formula. How long has this been going on? Is it a new phenomena, or is this the way it has been.... Quote Link to comment Share on other sites More sharing options...
Alshere59 Posted June 12, 2011 Report Share Posted June 12, 2011 Hmm its been hot in Saint Louie lately. What does your temp gauge do after running the engine a bit at speed then idle? I would be looking at the fuel lines etc. for routing and heat issues related to that. Any recent changes or repairs? Quote Link to comment Share on other sites More sharing options...
Jim Saraceno Posted June 12, 2011 Author Report Share Posted June 12, 2011 Heat Riser?Fuel mixture, not quite to the old girls liking till she warms up a bit. Could it possibly a shortage of fuel delivery momentarily. This crappy ethanol blended gas, maybe has something to do with that formula. How long has this been going on? Is it a new phenomena, or is this the way it has been.... Heat riser is fine. It does act like it is a fuel delivery problem but the fact that it is one hiccup then gone is what confuses me. That being said, I have not done a volume/pressure test on her lately. I need to do that to eliminate that possibility. This has been going on starting this year. Like I said, all the times I've had her out, it has only happened 3 times. I had a similar problem some years ago but it would happen while the engine was warming up, not after it was already warm. At the time I attributed it to the heat riser that was not functional. I fixed it and it went away. Hmmmm... Maybe that heat riser is getting stuck on occasion... I'll have to check that out again. What does your temp gauge do after running the engine a bit at speed then idle? I would be looking at the fuel lines etc. for routing and heat issues related to that. Any recent changes or repairs? The temp runs a pretty steady 180 degrees. It will rise above that at idle so that could be a possible issue. I have a heat shield installed above the fuel pump and heat shield tubing covering the line from the pump to the carb so I would think that is the issue. There have been no recent changes or repairs, I have done close to a complete maintenance, oils, plugs, points, etc. but i happened the first time before I did the maintenance and twice since. Okay... So I'll check the fuel volume and pressure and the heat riser and see what's up with those. Quote Link to comment Share on other sites More sharing options...
Chester Brzostowski Posted June 12, 2011 Report Share Posted June 12, 2011 Jim, Both my 48 and 1929 Plymouths do this to some minor extent. Never to the point that I am concerned about it. The 29 does this more frequently and usually at the starting point of an acceleration or change in acceleration. This makes sense in that the 1929’s carburetor does not have an accelerator jet. I have been adding a gallon or two of high octane which seems to help and have the lead additive but never get around to using it. If it’s happening when you are accelerating it may be the acceleration jet, pump, or your fuel reservoir float might be set too low. If the motor is good, you know compression etc. and the electrical items have recently been replaced, points, wires, and coil. I would do a carburetor rebuild. My 2 cents, Chet… Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted June 12, 2011 Report Share Posted June 12, 2011 I find that if I lug my engine (such as not downshifting when I go around a corner) that my engine will miss fire a time or two then clear right up. It has done this from the first time I drove it after the rebuild. If I dont lug it it runs fine. Quote Link to comment Share on other sites More sharing options...
greg g Posted June 12, 2011 Report Share Posted June 12, 2011 have you checked the coil wire to the distributor??? Is the wire firmly seated i the dist cap? Quote Link to comment Share on other sites More sharing options...
Jim Saraceno Posted June 14, 2011 Author Report Share Posted June 14, 2011 Thanks for all the ideas, I have a few things to check out. If it’s happening when you are accelerating it may be the acceleration jet, pump, or your fuel reservoir float might be set too low. If the motor is good, you know compression etc. and the electrical items have recently been replaced, points, wires, and coil. I would do a carburetor rebuild.I find that if I lug my engine (such as not downshifting when I go around a corner) that my engine will miss fire a time or two then clear right up. It happens at a steady speed, already in third gear, not close to lugging. Again, the car has been driven for a while, stops or idles for a minute or so, gets back up to speed, bucks two or three times, then fine for the rest of the day. I've had it out many times and this has only happened three times. that's what makes it so confusing. I've recently replaced the points, plugs, done a compression test. (The compression test shows #4 @ 125# and all the rest at 135-140#.) I have not checked the coil. I rebuilt the carburetor several years ago. have you checked the coil wire to the distributor??? Is the wire firmly seated i the dist cap? I did that the other day, but I've had the cap off since then so I will check it again. I think I may have a chance to work on her this week and I'll let you know what I find. Thanks again for all the input. Quote Link to comment Share on other sites More sharing options...
Jim Saraceno Posted June 17, 2011 Author Report Share Posted June 17, 2011 I just did a volume/pressure test on my fuel pump. The pressure came in at close to 4 3/4 pounds and held steady. The volume came in at just 5 ounces in 15 pumps which is within spec but just barely. I have two fuel filters on her that are two to three years old so I'm going to go ahead and replace those. I also realized that the fuel pump heat shield had been removed. I don't remember why I did that but I put it back on. I can easily imagine this could have caused the problem. The heat riser seams to be just fine and all the plug and distributor wires were seated properly. We'll see if I have any more problems. Quote Link to comment Share on other sites More sharing options...
greg g Posted June 17, 2011 Report Share Posted June 17, 2011 Don't kow the specs for the early cars but p15 are supposed to yield 8 to 10 ounces per 12 strokes. Quote Link to comment Share on other sites More sharing options...
Jim Saraceno Posted June 17, 2011 Author Report Share Posted June 17, 2011 Don't know the specs for the early cars but p15 are supposed to yield 8 to 10 ounces per 12 strokes. Gregg, where did you find that spec? I have the Plymouth service manual from '46 - 54 and it states 5-6 ounces in 15 pumps. Quote Link to comment Share on other sites More sharing options...
greg g Posted June 17, 2011 Report Share Posted June 17, 2011 My manual give the 8 to 10 on 12. Its a 46 through 51 reprint. Quote Link to comment Share on other sites More sharing options...
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