Help with apparent fuel related problem

Lawson Cox

Lawson Cox

Well-known member
:confused: After installing my South Wind heater in my truck I have problems with acceleration. The heater of course is off in this hot weather so I am not factoring the heater into the equation.

Fuel supply from 97 carb is the stock little tube that hangs on the carburetor body has a small tube that goes into the float chamber and draws gas from there. Tube not interfering with float as far as I can tell. Heater works as it should when it is turned on.

The engine ( basically stock 39) idles great, but when accelerating it seems like it is not getting enough fuel and is like a bucking horse.

I was having trouble before with carb running rich so I reduced the main jets from .045 to .044. to see if that helps. Other than that no other changes were made. Crab distributor. Skips coil.

So far I have only driven it 50-60 miles around town. I have not checked the plugs to see if there is a change in the "soot" on the plugs, but I doubt I have driven it enough to really make a difference in reading the plugs. I am going to install new plugs because I think that would help a little, but not the main issue.

All suggestions will be given due consideration.

Lawson
 
Lawson, it sounds like it could be a vacuum leak, check around the base of the carb where the Southwind connection is.
 
You of course, put a gasket on the top and bottom of the vacuum plate. With the engine at idel, spray some WD40 on that plate all the way around. If there is any difference in engine speed at all you have a vacuum leak to fix.
 
Lawson .If you pull the choke and it smooths out then its fuel ,like blocked jets ,Maybe you introduced some crud into the bowl .faulty pump ,Run it then when the symptoms appear switch of ,then lift the top of the Carb check the fuel level .If it happens only when hot its then worth looking into electoral ,voltage drop .run a jump wire from battery to resister /coil?,change, condenser .try another temporary coil .
 
Hey Mr LAWWWWWWWSON ; I agree with Vic. vacuum leak, upsets your dist.(crab) disconnect the vac. at the carb base, plug it off and go for a run,... when the heater vac is connected, the leak could be in the heater ?? You crawl in under the front seat, put your ear up to the heater, you should hear the leak ?? ...OK the heater is OFF give it a small shot of starter fluid,..your out in the open, doors open, engine is running at slow ideal, the engine should speed up if the leak is in your heater, you can also use the starter fluid around the base of the carb, check for the leak,, engine is running for this test also ... again be safe... with all that hot air and the engine hot, it could flash ,,, best to wait tell the engine is cool. ..or pooooof it could go...... OLD....BILL
 
Lawson, as was previously mentioned, use WD40, not starter fluid,:eek: to test for the vacuum leak... A lot less chance of singing your eyebrows or melting paint… ;)
 
Vic Piano said:
Lawson, as was previously mentioned, use WD40, not starter fluid,:eek: to test for the vacuum leak... A lot less chance of singing your eyebrows or melting paint… ;)
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I agree Vic. One thing I forgot to mention is that the engine will run wide open, out of gear, but put a load on it and it acts up as described.
 
OLD...BILL said:
Hey Mr LAWWWWWWWSON ; I agree with Vic. vacuum leak, upsets your dist.(crab) disconnect the vac. at the carb base, plug it off and go for a run,... when the heater vac is connected, the leak could be in the heater ?? You crawl in under the front seat, put your ear up to the heater, you should hear the leak ?? ...OK the heater is OFF give it a small shot of starter fluid,..your out in the open, doors open, engine is running at slow ideal, the engine should speed up if the leak is in your heater, you can also use the starter fluid around the base of the carb, check for the leak,, engine is running for this test also ... again be safe... with all that hot air and the engine hot, it could flash ,,, best to wait tell the engine is cool. ..or pooooof it could go...... OLD....BILL
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Starter fluid would be too dangerous for this test. And, I forgot to mention that I can floor board it, out of gear, and it doesn't skip a lick, but put a load on it and it acts up as described.

I'll check for leak with WD40 tomorrow in the "cool of the morning". lol
 
Yes your WD-40 would work, just watch it disapear in the leak, and your WOT and no dropped beets, but with load it needs vac/advance its not there with your leak ....so please tell my how the WD-40 going to work, if the leak is in the heater house its self.?? disconnect and give it a run .......OLD....BILL
 
Lawson Cox said:
Hey, if I really knew what I was doing I wouldn't be asking questions. LOL
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Sounds simple but do you have a gasket under the big nut where the vacume piston goes. ken ct. Also i always replace the rubber seal on the back side of the unit. The rubber must be proud of the gasket surface to work.I always put new ones in. ken ct.
 
Why does WD40 work?? It has propane for the pressure. The gas pushes the product oil, paint or whatever out the spray nozzle. How do I know, I had a to fill spray cans and used Freon 12 which cost $660.00 for a ton container now it's about that price for a 30 lb cylinder. Then most industrial plants banned Freon and we had to go to CO 2 because the propane could explode if the spray was used in a confined area when welding. G.M.
 
ken ct said:
Sounds simple but do you have a gasket under the big nut where the vacume piston goes. ken ct. Also i always replace the rubber seal on the back side of the unit. The rubber must be proud of the gasket surface to work.I always put new ones in. ken ct.
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Haven't touched the distributor. Just had to R&R carb to install vacuum plate. Bubba did my distributor with his one for two deal a while back.

I think it probably is a leak in that area. I had to make do with gaskets I had on hand. Maybe one of the gaskets was bad or I didn't tighten down well enough on the carb base.

Tomorrow is another day. lol
 
Still a possibility the pickup tube in the bowl is interfearing with the up + down of the float. There ins't much room in there for the tube?? ken ct.
 
ken ct said:
Still a possibility the pickup tube in the bowl is interfearing with the up + down of the float. There ins't much room in there for the tube?? ken ct.
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That would not be the problem. I drove around for an hour before I discovered the problem at higher speeds. Float bowl doesn't hold THAT MUCH gas. LOL
 
ken ct said:
Still a possibility the pickup tube in the bowl is interfearing with the up + down of the float. There ins't much room in there for the tube?? ken ct.
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Rejoice with me for I have found and remedied the problem. Checked everything twice and found nothing. I decided to take the brass/copper lines for gas and vacuum for the heater off and put some Teflon tape on them, very carefully so as to not get any tape into lines. Tightened them up real snug, went for a test drive and it is running like a finely tuned Swiss watch again.

Thanks for all the tips fellows.

Lawson
 
Lawson Cox said:
Rejoice with me for I have found and remedied the problem. Checked everything twice and found nothing. I decided to take the brass/copper lines for gas and vacuum for the heater off and put some Teflon tape on them, very carefully so as to not get any tape into lines. Tightened them up real snug, went for a test drive and it is running like a finely tuned Swiss watch again.

Thanks for all the tips fellows.

Lawson
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Then you didn't have the fittings tight enough. TEFLON tape is a NO-NO. Some people dont learn. You will be headed for a carb clean out.LOL.. ken ct. Or a plugged up and dont work anymore heater.
 
I have heard that, that is why I was very careful NOT to get any tape anywhere close to the holes in the tubes. The lines were snugged up very tight in the first place. I didn't, and don't want to plug anything up. Maybe I should remove the tape and put a little lube on the threads where they will tighten a little better. What say you?
 
Yes i would do that. The tape will work its way in no matter how carefully you put it on.Believe me. ken ct. These fittings do not seal at the threads its on the bevel of the nut or collar on the tube.
 
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