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Another Carburetor problem?

KentC

KentC

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Feb 24, 2004
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Age
73
Location
Lubbock Area
Website
www.crutchercpa.com
After getting warmed up, on the 4-lane, at 60mph, the engine starts to cut-out, then loses power, jerking as it does so. I slow and at about 10mph it dies. With 2 pumps, it starts right up. It goes for a couple of miles and does it again.
It is a 1960 engine, factory carburetor for a 53' 3100. It has two fuel filters, one next to tank, the other next to carb. It has a new kit, new fuel pump (manual, ORielly cheapo), new flowlines and a clean outlet plug from the tank. All the electronics are new and the values are correctly adjusted. Thinking it was a piece of dirt, I used some carb cleaner, but it did not change anything. The problems does not occur at low speeds, except after the higher speeds (60mph). What is this about a line pressure device in the previous email? I cannot determine if it is flooding or not getting enough gas.
Thank you.
KentC
 
Kent,

I'm probably not the best one to give advice since I am still having some problems with my carb, as well, but I can answer a couple of your questions.

I had similar problems the last time I got my 1962 235 running. I drove it a few blocks down the road and it seemed to be running fine. When I decelerated it died and didn't want to restart. I got it running after letting it cool a couple of minutes, but it died after only running a minute more. I ended up towing it home. I haven't been able to get it running since... still working on it.

The suggestion from VWNATE was to add a fuel pressure regulator between the carb and fuel pump. My problem was that the carb wanted to dump fuel like the float was sticking. I purchased a regulator at Autozone for about $20.00. I was fiddling with it's settings when this latest problem surfaced. It still wanted to dump fuel, even with the lower settings like 1 1/2 or 2 PSI. It has been raining so much I haven't had a good chance to get back outside to the truck. (Mine is too big to fit in the shop).

I, too, have two fuel filters now. One is just ahead of the pump and the other literally is screwed into the carb inlet. I have confirmed that I have fuel to the carb, but I can't seem to get the truck to start right now. I'm trying to see if I can figure out why. It acts like my old valve adjustment problem has returned for some reason.
It looks like time to pop off the valve cover and check things out.
 
The jerking makes me wonder if maybe the condensor is bad ? I've had more than a few brandy new ones go bad , the usual symptom is :

Starts & runs fine but the power goes all herky - jerky as the engine begins to warm up....

It's a simple thing to pop the old crappy looking condensor back in for a test...

BTW : condensors DO NOT " take a burn " to the points , if you're ever lucky enough to get a set of evenly pitted ign. points , SAVE THAT CONDENSOR as it is _prefectly_ matched to your ignition system !

-Nate
 
The vehicle has a condensor on the outside of the ignition coil frame and one inside the distributor, where the points are. I did not do it, but left it alone as is was running fine. The one on the coil frame I replaced a while back, but not the one inside the distributor.
Kent
 
RE: Condensors

If they're both connected to the points wire , junk one of them ,

If one is connected to the hot side of the coil , it's a radio static suppression condensor , leave it there even if you don't have a radio yet .

-Nate
 
RE: Condensors

Are you saying permanently remove the one from inside the distributor (I do not have a radio) and replace the one on the coil with a new one - to see if this will correct my road problem above?
Kent
 
RE: Condensors

That might be worth a try ~ I like and prefer the inside condensor , you could remove just the external one to test and if that makes no differance , try replacing the other one .

NAPA condensor P/N is : CS763A for '49 ~ '62 models....

Please go back and carefully read my post as if one condensor is attached to the hot wire from the key , it's unlikely to be causing any troubles...

-Nate
 
RE: Leaks and Springs..

[updated:LAST EDITED ON Jan-21-06 AT 10:07 PM (CST)]Kent,

I spent most of the day working on my 235 today and, as I stated in an earlier post, I have similar problems. Today I changed out the condensor and that did no good. I put in a new set of plug wires because one was slightly cut. Again, no better. My son was helping me and he thought that the way I ran the Fuel line around the valve cover, close to the water thermostat housing might be causing it to vapor lock. We did a temporary relocation. That helped a bit but it was still idling very roughtly when it warmed up and then it would begin missing and evenually die.
I went to the old shop manual and checked the troubleshooting guide under "Rough Engine Idle" (Page 6-44). The second section is Air Leaks. Items C & D did the trick... Air leaks in the Windshield wiper vacuum line and Air leaks in the Hydrovac or 2-speed Axle Vacuum cylinder lines. I removed both these lines and then plugged the tap where the tee connected to the intake manifold below the carburetor. This, of course renders both the wipers and hydrovac brake booster inoperative, but it allowed the engine to idle smoothly until it warmed up.
Another thing I found while checking around this area answered another question. I noticed while I have having trouble earlier that if I primed the carb with gas the enginer would start right off, but at one point the gas vaporized and sizzled when I put it in the carb. This indicated that the carb was getting much hotter than normal. I checked and, sure enough, the manifold thermostatic spring was not opening the heat riseer valve, allowing it to remain closed. This routes hot exhaust to the intake manifold. This is desireable while the engine heats, but overheats the intake and essentially vapor locks the engine once the engine is hot. It can also toast valves. I manually pulled the valve open and held it there. The engine took a minute or so to cool the intake, but then the engine was much more smooth. If I let it close it would take a minute or so and it would start to run rough again.
You might want to check these things to see if maybe you have a vacuum leak or a problem with the thermostatic spring on the heat riser. Also verify that the heat riser rotates smoothly and doesn't hang in either the open or closed position. I am now a believer that this part is often overlooked as a source of trouble. I know I did. I assumed that if it moved it was working. That ain't necessarily so.
 
RE: Leaks and Springs..

I replaced the condensor and it still cuts out after the warm up, but not as much. It acts more like a timing or point problem now, but those are set perfect. It is odd that as I slow to a stop, it dies. Then two pumps and it starts right up and runs good for a few miles, then starts the process again.
The exhaust spring does not stick, but I do not know if it is a good one. I set it according to the manual. I will try pulling the wiper tube and doing as you instruct. But I am not sure about the other vacuum line you speak of the 2 speed axel vacuum line. I do not think I have one of those (not sure though).
The vehicle starts good, runs good, except at highway speed, 60mph.
Thank you.
Kentc
 
RE: Leaks and Springs..

My truck is a '49 1 1/2 Ton Flatbed. The larger trucks used a vacuum brake booster called a Hydrovac unit. There is a very large brass pipe running basically from the intake manifold vacuum tap across the firewall and down under the right side of the frame to the hydrovac unit. It is coupled together with one or two rubber hose sections in some cases. There may be leaks in that vacuum line, if you have one.

I just made another discovery on my truck which had a similar problem of not wanting to run when hot. It turns out the fuel pump had a tear in the upper diaphragm. Mine is a '62 engine and doesn't have the glass bowl on top. I replaced the fuel pump with a newer style that is a combination fuel pump and vacuum pump. The upper fuel pump section works just fine to replace the older fuel pump, it bolts right on. They were used until everyone switched over to electric wipers. The lower vacuum section is intended to splice into the vacuum wiper line (assuming you have vacuum wipers instead of electric) to provide additional vacuum so the wipers don't sag at high RPM or on acelleration. I figured I may as well try to solve two problems at once. I got the pump at the local Car Quest dealer for about $50.00. Napa and Autozone also have both types of pumps. Stock pumps run about $35.00 and the dual setup will cost between $50.00 and $75.00. It pays to shop. Now the truck starts reliably and will idle forever whereas with the old pump it would start when cold, run a couple of minutes, and then die. After that it was a bear to start. I would prime it with gas in the carb and it would kick over but die as soon as the prime was burned off.
 
RE: Leaks and Springs..

No I do not have the brake hydrovac.
Yes, my next "solution", if the other does not work, was to replace the fuel pump with one that assists the wiper motor. The motor has a new overhaul, but the action is pretty sad looking upon any acceleration (stops completely). Again, thank you.
Kent
 
RE: Leaks and Springs..

You may want to look at your fuel pickup in the tank and your rubber gas lines. I had a similar problem in an older van. It would run fine a lower speeds but when you got up to highway speeds the sock (pickup filter)in the gas tank would suck closed and cut off the fuel supply. The inside lining of old gas line hoses will also do the same thing if they are deteriorated. The van would sit a few minutes and then start and run fine. I havn't looked in my 54 tank yet to see what the fuel pickup looks like but it may be worth a stab.
 
RE: Slow / Stalled Wipers

[updated:LAST EDITED ON Jan-31-06 AT 10:38 PM (CST)]
That is normal for them to stop if you stamp on the acellerator .

Valve adjustment makes a _HUGE_ differance on how fast your wipers run as does correct ignition timing so ensure both are spot on .

You can also go to junkyard and look for old metal vacuum resivoirs , old Fords products used nice metal resivoirs made of....

# 10 Tomato cans with two hose nipples soldered into the lid ! these were stock on nearly all Ford passenger cars from the 60's into the late 70's and never wear out , cost about $3.00 . Lincolns have them too and if you look at the vacuum hoses you'll find a plastic one way check valve you can install to keep the vacuum in the can from bledding off when you acellerate.... hide the can and valve up under the dash .


-Nate
 
RE: Slow / Stalled Wipers

I just installed a combo fuel/vacuum pump in place of the standard fuel pump. The upper section is a fuel pump and the bottom is a vacuum pump that runs off the same drive. The combo pump costs about $50.00 at Car Quest versus $35.00 for a replacement fuel pump. Supposedly this vacuum pump connects in the line with the wiper hose from the intake manifold. When the intake manifold is delivering sufficient vacuum the wipers will operate. When you accelerate the combo pump will speed up and boost vacuum to keep the wipers running at higher RPM. I haven't actually hooked up the vacuum side yet, but I did feel a decent suck on the port even at idle.
 
RE: DA Fuel Pump Hose Connections

The correct way to connect this is : identify the suction side of the DA fuel pump and connect the wiper motor to that , now connect the old intake manidold nipple to the other fuel pump nipple , in this manner you'll always have 21" of vacuum to keep those wiper flip flopping in the heaviest rainstorms .

Generous Motors had this all figured out in the 1930's....

BTW : Airtex brand (the largest water and fuel pump mfgr. in the WORLD) still makes the Dual Action fuel pump for our 6 cylinder engines , it doesn't have the glass bowl filter but it' only $35.00 list price....

I poseted the P/N last year...should be in the archives .


-Nate
 
RE: DA Fuel Pump Hose Connections

As always, Nate, thanks for the tips. I hope to work on the truck some more this weekend if I can get to it through all the water and rain (that's a joke). I got the front half of the headliner in last night after I put in the Insul-Tek roof insulation. I will put the back half in after I paint the back retaining strip. Then it's on to putting down the flooring. It's coming along.
 
Sputtering at higher speed

The vacuum from the carb to the wiper motor was ok, plenty of suction. But I changed the exhaust spring (old one was rusty) on the exhaust manifold. On the 4-lane test run, it looks like this might have solved the problem - no more jerking and sputtering at higher speeds. Thank you
KentC
 
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