The Stovebolt Site Forums The Shop Area Engine Shop Help!!! Engine Cutting Out, I,m Stumped.

My engine just started cutting out on me when I have driven about five miles. It acts like it is running out of gas. I have a new fuel pump, new fuel filter, new points and condensor, cap and rotor. I have a half a tank of gas. My compression is 120 - 150lbs on all cylinders.

My truck did run at 220* for a while, but the water and oil look ok so I don't think the head is warped plus the comprssion is good.

If I keep the choke closed it helps allot, if I open the choke the truck just shuts off. Vacume leak maybe?

What is the knob on the side of the distributer?

What gives? :confused: Any help would be appreciated.

It only happens after the truck is warmed up and driven for a short while, idles fine when cold.

Sounds like a fuel starvation problem. A vacuum leak would make the engine run rough, even at idle. Since you have a new fuel pump and fuel filter you've eliminated the usual culprits. It could be the line from the tank to the pump is clogged with something but I'm not sure how to check this other than disconnecting the line at the inlet to the fuel pump and see if fuel is running out freely. The only other thing I can think of is maybe a carb float problem. Hopefully someone else can come up with some other possible causes. Good luck!!

waldo53....YEP..I agree. The kinked rubber fuel line under the gas tank that's what happen to me on the 54 had to look real close the line had sucked itself closed and a little gas was getting by. Give it a good look over Rcimp, Steve

Could be the tank is not vented, try removing the gas cap when it acts up, if it instantly gets better you know what it was. With a helper you can even remove the cap while driving.

A collapsing fuel line sounds like a good reason too.

"knob" on the side of the distributor should be a grease cup to grease the shaft.

Grigg

Rcimp,

I have heard about this but never experienced it personally. The coil can fail as it warms up. Pulling the choke out enriches the fuel/air mixture and allows a marginal spark to fire the fuel. At first glance, fuel starvation seems to be the culprit, but this isn't usually a temperature sensitive issue. Keep us posted when you find the answer to this problem.

Stuart

coil

Hi Rcimp, if none of the above suggestions work, I wouldn't necessarily trust your fuel pump just because it is new. A few months ago I put a new one my 235 and it ran great for about 30 miles. Then for some reason it would no longer pump enough fuel when the engine was at cruising speed. But it would pump enough at an idle. So I went and put an old pump on and everything was fine. Also, don't forget to check the condensor. Good Luck.

I had that same problem years ago,with an Oldsmobile. Turned out it was a flexible fuel line collapsing.Mine was just ahead of the fuel pump.A good thing to ck.for.Check for any flexible (rubber lines) between the tank and the fuel pump.If you can squeeze them shut they are shot and the fuel pump will suck them closed.

Thanks for the suggestions, I will just go ahead and replace all of the rubber fuel lines on my old truck and just get that out of the way. I found out when I turn to the left fuel poors out of my tank into the cab. My wife put her hand down where the filler neck goes into the tank and felt gas poor out as we were turning left, those fuel filler hoses need to be replaced to.

I was thinking of installing the pertronix ignition system anyway so I will get one of their coils to go with it.

It did cross my mind that I had a bad new fuel pump or float or needle/seat problem.

Keep us posted! Hope you get 'er going soon.

I had the same problem but more severe. It turned out that it was the gas tank itself. Since you need to replace the filler neck. Check the inside out. It may appear outwardly fine but espicially if it is the orginal tank it could be rusty. I would run my car and then it would die or simply not start until I got the lines cleared. If this is the case and a new tank is to much I would suggest a gas tank sealant. Used it in my 49 and have had no problems with.

Thanks Delux, I will take a close look when I replace the filler neck tubes.

Also rust flakes and crud in the tank. As the truck runs it draws the particles around the tank outlet...and yes starvation occurrs. I've had this. Blu out the lines and flushed the tank.

You have a number of possibilities.

Keith

Well it is not the coil, I replaced it with a known good one and I still have the problem.

I still don't know why when I close the choke the truck runs better. I always thought that meant a vacume leak.

I will check the tank and hoses next. I bet the tank is full of rust and dirt etc. etc.

Rcimp,

Great work on taking the coil out of the equation. Choking off the air through the venturi forces the engine to pull more fuel through the carburetor. This is pretty simple mechanics....you indicate your truck starts and runs fine until warm, or about five miles. Using this fact one would look for something that is being affected by a warm condition that isn't present in the cold engine.

Any static condition in the carburetor, like a float that is set too low, won't change with engine temperature. Your thoughts on the choke and a vacuum leak or right on target...but this wouldn't be temperature sensitive.

Sort of thinking out loud, valves that are set way too tight will not seat properly after they warm up. This could cause a loss of vacuum which pulling the choke out would help.

If this problem is really brought on by a increase in engine temperature, and not by the 5 miles driven (fuel starvation), then it probably isn't the carburetor that is at fault.

Stuart

I never thought about the valves, I did adjust them when I first got the truck, they were really rattling. I think I will warm it up and check my adjustment. I still have to replace the fuel lines.

This truck won't even idle after warmed up now unless the choke is pulled almost completely closed. And when I did my compression check the truck was cold.

Rcimp,

In an ongoing effort to nitpick this problem, will the engine start cold, idle fine, then as it comes up in temperature, lose the ability to idle unless the choke is progressively closed.

If you start the cold engine with the truck sitting at the curb, never move it, and let it idle, will it sit there running forever, or will it eventually die by itself?

Stuart

Sorry for the late reply Stuart, I'm taking some night classes and time is scarce.

To answer your question, I am not sure. Let me start from the beggining.

I had to drive the truck to the license division about 20 miles away. I drove it on the freeway at 60 mph. It did fine there but on the way back the temp guage climbed to the 212 mark and stayed there. I pulled over and popped the radiator cap and added about a pint of water. There was no steam or boiling over or any common overheating signs. I got back in and was driving home on a side street and the truck started cutting out. I pulled the choke and it did better. I just wanted to get it home. Well it finally just quit running all together and I had to pull over. I called for a tow truck, I waited about 15 minutes and it started up and sounded fine. I started to drive it and it seamed fine then in a short distance it cut out and then stopped running. I did this several times until I got it home.

When it is cold it starts and idles fine, even after it warms up a bit, it seams to idled fine. It is only after I drive it that it starts to cut out, and then won't run unless the choke is all the way closed.

Rcimp,


I'm on the verge of being stumped myself. Although the overheating deal doesn't add up, my next suggestion would be to take a compression check. I didn't think the AD temp gauge actually had numbers on it to indicate temp in degrees.

If you somehow knew the actual temperature was 212&deg, you should have had some activity when you popped the radiator cap, and it certainly should have gulped more than a pint of water.

If you try to tie the overtemp problem in with your other problem, about the only possible correlation I can see would be a blown head gasket or ignition timing that went askew.

I think more intense detective work will be needed before this mystery is solved. Take a compression check, watch the coolant level and keep an eye on the tailpipe for steam. Keep us posted.

Stuart

Rcimp;
Did you get a chance to look at your tank and hoses yet? Is a good stream of fuel getting to the inlet of the fuel pump?

To check the fuel pump you could pull the gas line off the carb and let it run into a can while the engine is idling. Should see a good stream of gas even at idle.

Keep us posted.

I have seen condensers that break down when they get warm and act like this. A weak spark will ignite a rich fuel mixture better than a lean mixture, that could explain the running better with the choke on.

I believe Pre '68 Dave may be on to something. A weak spark from either a bad condensor or a heat degrading coil could IMHO cause this problem.

I have replaced the points,condensor and coil. It still cuts out. I Haven't had the time to look at the fuel lines yet. I am thinking it is fuel lines or I have adjusted the valves to tight. When I figure it out I will dig up this post and let everyone know what I have found. Thanks for all the tips.
Randy

Since your radiator water wasn't hot after the long drive, perhaps the water is not circulating and the engine is cutting out because it's overheating.

Pulling the choke in this over-hot condition will really pour fuel into the cylinders, essentially causing the hot motor to diesel and continue running.

I can see the water movement in the radiator, I am going to pull the radaitor and have it profesionaly cleaned, and install a new water pump, and T-stat just to be safe. Then I will know what I have as far as a cooling system.

I have experienced symptoms like this, Changed plugs, points, condenser , coil, rebuilt carb, NO Change! By chance, I went from a 195 degree thermostat to a 180 degree thermostat. Problem went away and has not returned in 2 years. I think with a 195 degree thermostat, the fuel was boiling in the carb under hood. For what ever its worth to you. Jerry

Rcimp,
I would check your fuel system first you said when you turn left the fuel pours OUT! that means there is nothing from stopping dust dirt and small dried out peices of the hose from falling IN! the running hot could be the lean condition it is running in due to fuel starvation.You also say it starts and runs after it sits awile sounds like floaties in the tank to me.
DS

I think it might be a fuel problem to, as soon as I get the chance I am going to replace the fuel lines and I am going to try and remove the tank and have it cleaned and sealed.

I sure appreciate all the suggestions

you know I had a problem like that too, happened when the engine would heat up. In my case the problem was vapor lock in the fuel line cuz the line from the pump to the carb was resting on aheater hose. So when engine heated up the fuel would too till the point it vaporizes, the more you rev the engine the hotter it gets. The engine would spudder and then quit, let it cool down and start it up again it'd be fine. I don't know if that's what's going on here but just thought I'd put that out there.

-Danny

I finally had some time to look at my truck. Here is what I did:
The fuel pooring out inside the cab as I turned left was caused by a corroded hose on the filler pipe, actually is was the little vent hose that was corroded. Replaced filler and vent hoses.

For the cutting out issue, I crawled under my truck and notice a shut off valve under the tank and a rubber hose connecting it to the metal fuel line. It was pretty weather worn. I turned off the valve (I was amazed it worked) and cut off the old hose. Installed a new hose and turned on the valve and let it drain in a bucket. Some dirt or rust came out at first then is was flowing clean and freely. I installed the hose to the fuel line. Started the truck and let it completly warm up then I went for a drive. It never cut out on me and it idles with the choke wide open.

I sure hope that the shut off valve was partially blocked by this dirt (or rust) but I am skeptical. Only time will tell.

I also moved the fuel line going to the carburator farther away from the t-stat housing and radiator hoses.

This sounds way too familiar! I have a '40 1/2t with a '58 235 that this summer behaves just like this, fuel starvation after running awhile. I have put at least 8000 miles on her over 2 Years without changing anything but gas and oil.Vapor lock was suggested and I tried an old "fix" of clamping wooden clothes pins to the fuel line(?), and fabbing a new bracket to hold the fuel line farther away from the front or the block. No help! Crud in the tank doesn't seem probable due to no crud visible in the filter and the fact that sometimes I can drive it 30+ miles at a shot without a wimper or hiccup. I will now try replacing fuel lines since the problem seems to be heat related somewhat(100+ degree days might soften an old rubber line). Thanks, I hope it helps.

I've heard this song, too. I've had some problems like this a few years back, and sure found some rust in the crudy old shut off valve. I expect your problems will return, and that in the end you need to clean out or replace the gas tank. If there is crude in the shut off valve, then there is probably crude (more than you can drain out without removal) in the tank. What you might find out in a month or two is that bouncing around on those Texas roads is going to continually loosen rusty crap from the inside of the tank. If it has never been done, you should expect that a 50 year old gas tank needs some TLC. There have been a lot of posts about the best way to clean a tank, or whether its better to replace. I cleaned mine. Do a search on the topic and big piles of wisdom will fall on you.
Karl