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Hey guys... Im running into a problem. My 68 will idle fine and run in 1st. When I get up to speed usually between 2nd and 3rd it will cut out. The oil gauge drops to zero. Then it normally takes a few minutes before I can fire it back up and usually cuts out again when I take off. Seems like the carb is flooding but im not sure. Anyone run into this before or have any ideas for me.
My M725 ran fine for about a month when I first started working on it. Then, it would only idle. I could not give it any gas or it would stall. I had the fuel pump rebuilt, same result. Had the carb rebuilt and it runs now, but rich. Mine now needs the timing adjusted, new plugs and idle mixture adj.
I'd check the fuel filter, fuel pump, tank pickup sock, and the needle valve in the carb, in that order.
A fuel pressure gauge may come in handy, or you can just pop lines off and see what kind of flow you can get.
--Randy
Could also be an ignition problem, such as a bad coil failing when warm.
--Randy
Easy way to check the fuel pump is to see if it will fill up a small water bottle in less than a minute while cranking the engine. You will also see if there is any gunk in it.
The fuel tank has a plug on the bottom. You can drain the tank and put in fresh gas.
ive replaced the fuel filter already so I think its time to play with the fuel pump. Thanks for the help fellas. I'll let you know how it goes
Many Zoners have posted to put a second see-through fuel filter on the rubber hose where the fuel comes out of the fuel tank, and before the fuel goes into the metal fuel lines on the side rail. This keeps "clean" fuel flowing through the lines and the fuel pump.
Good luck!
Since my carburetor had rust in it and the tank is a mess, I have decided to buy a new SS tank from Mike and replace the fuel lines from the tank to the engine. They are easy to get at and not made of anything exotic. I have a double flare and tube bender so with all new parts, I hope to be ahead of the game. I will most likely replace the still original rubber fuel line that goes from the frame to the engine with conventional rubber fuel line. I also intend to use high pressure fuel line designed for fuel injection and high pressure clamps. Yes, it costs more but I hope to only do this one time.
I will let you know how it goes. I just can't see taking the time to rebuild the carburetor (I already did) and then just pump rust into it again. I am undecided as to whether I will put another filter at the tank. I think that using a new tank will eliminate that issue.
Pix of the carb before rebuild and the "nasty" tank.
http://www.streitsonline.com/don/carb_rust.jpg
http://www.streitsonline.com/don/Tank.jpg
BTW, when making fuel lines, here is one trick you may want to use if you have a double flare kit. Clamp the line as per directions with the kit. Use the little metal disc that starts the double flare and make that bend. Then just use the tubing as you have just prepared it. It will put a little barb on the end of the line not unlike what the manufacturers do and help the clamp hold the rubber hose on.
A filter at the tank also protects the pump from anything that might be added to the tank, not just what's from the tank... Old jerry cans, crap from gas stations' tanks, etc.
--Randy
Now that my truck is running, I'm beginning to drive my truck around the neighborhood. This way, if it quits on me I can easily walk home to get my CTD tow vehicle. I drove it initially to get 2/3s a tank of gas, and I have driven only about five miles or less since I got it started. Already, the see-through fuel filter I installed where the rubber hose comes from the tank is half filled with a brownish mud-looking sludge. The fuel filter at the carb is just brown from the fuel. Engine runs rough still. I need to adjust the mixture and the timing, but I'm waiting for my new/used Snap-on timing light.
my$.02
I think that you have found the problem: contaminated fuel. If it is from a rusty tank, you may need to deal with that or replace the tank. I am sure you don't want to hear that (I didn't!) but that to me seems to be the root of the problem.Quote:
Originally Posted by MJCougler
My carburetor was filled with powdered rust. I rebuilt it and didn't want to fill it up again with rust. So I bit the bullet, spent money I didn't have and ordered a new tank from Mike. Last week, I replaced the fuel line from the tank to the rubber hose at the engine. I removed the steel line from the rubber hose to the fuel pump and it was clean and no rust. I removed the flared end from the engine fuel line and crimped a "barb" on it. Then, I used plain old 5/16" rubber fuel line to connect the two hoses. Still waiting on the tank to attempt a first start...
DON; Anyone?
I may have another problem besides contaminated fuel. Yes, the truck idles rough. But, I am also wondering about the two-notch gasket I installed under the carburator.
The instructions that I downloaded from the Holley website states the two notches go toward the idle screw side of the carb. But, I read a post or stickey recently that said I need the four-notch gasket. And, the parts manual shows a carb gasket that does not have any notches. Which is correct?
I mounted the 2-notch gasket with the notches toward the idle screw (toward the valve cover side). It idles rough. I do need to adjust the timing, but the question still remains, anyone have the page that describes the correct carb gasket?
Yes, I have dirty fuel, but do I also have the wrong carb gasket?
Thanks again team,
Mike, I am not sure about the gasket. But if you have had and maybe still do have dirty fuel, maybe the carburetor and main jet are gummy or clogged again. If you have another bowl gasket, you may be able to take the bowl off while the carburetor is still on the manifold and spray out any contamination with something like Berkebile 2+2 Gum Cutter. That stuff works well for me (Not nearly as good as it was in the early 70s:(.)
I looked at the exploded picture in the 34P manual and it shows two cut-outs facing the engine. But sometimes, these illustrations are approximate and not to be taken literally. I know it is frustrating.
(A little OT) I may be able to start mine today for the first time. I don't have the new fuel tank today. But I have just about corrected all of the "modifications" to the original wiring. My intention is to strap a 5 gal Jerry can into the holder on the driver side and put a 5/16 rubber hose from the fuel line to inside of the can. Wish me luck!
Check this out:
http://www.streitsonline.com/don/1920_Holley.jpg
And for what it is worth, my carburetor is missing #76 the baffle. I also found out the jet number in my carb is #692. Hope that is original.
BTW, my reference to the manual above is incorrect. It is actually the -34 manual, not the -34P as I stated. Sorry for that "Senior Moment". They seem to be more frequent as life goes on.
having a problem with my truck today, all stock and have a spare parts on pallet racking......no gas to carb at all, took off line to fuel filter which is after fuel pump and cranked truck and no fuel.........b4 i switch out my fuel pump any thing else to try??? thanks for any help...........
no fuel = bad pump (or plugged line at tank).
I would change the pump, blow the line out back into the tank. change filter.
Also, you can disconnect the short line from the frame rail to the engine and feed in fuel from a 5 gal can strapped to the front bumper. I do this to test the pump and get trucks running all the time.
I fought a rusty tank the whole time I owned my Hercules M37 because I wasn't smart enough to have it cleaned out, or even buy an NOS replacement. Removing & cleaning the filter element from a Bendix-type interruptor pump by the side of the road at night was typical and hateful.Quote:
Originally Posted by Don Cavey
thanks much, never thought of that, once drove a old jeep home with a 5 gallon can strapped to the roof!!!
This what I did when I was waiting for my new stainless steel tank. I refused to be bothered with a rusty tank. They come back to haunt you.
Trouble with this was that when I drove around the yard, the gas sloshed out of the can!