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Thu May 24, 2007 12:58 pm

The history to my problem started about 3 weeks ago when my wife and I went to a dinner function and drove our 74 thing. We made the 10 or so mile trip and the car died in the parking lot. I was able to check the carb by seeing if any fuel was being sprayed by the acc. pump, in which there was non.
I towed the car home and tryed to start in the next morning. It started and until yesterday it was fine. I had driven it enough in the last 3 weeks to burn 2 tanks of gas.
Yesterday it did it again, after driving it for about 15 miles (I had driven the car on 60 mile round trips before wiht no problems). After towing it home, it started again.
Heres what I did last night to try and correct any problems.
1) Ordered new fuel pump ( the're eithe good or bad most of the time, not intermittant).
2) blew air through the lines. (no blockage that I could see)
3) Took fuel strainer soch out of tank and cleaned soch (Looked obstructed) and rinsed tank out.
4) Replaced front fuel line and filter.
5) Took fuel pump out and checked push rod (plenty of play, and moves freely).
Today it happened again, the 1st time was after picking up the replacement fuel pump. I did the switch in a empty parking lot.
And then again 4 blocks from my house, in which I walked home and then went back after 2 hours (started right up :roll: ).
I replaced the rear rubbler hose going from the rear horn to the engine compartment, thinking that I may have a colapsed hose. But the old line was not collapsed.
Any one got any ideas that I may be missing?
I forgot to mention that in the last 2 days, I have taken the fuel line off the carb. and there is no fuel comming out when the engine is cranked.

Thu May 24, 2007 1:09 pm

-You said "no fuel when cranking" Did you also check the feed line to the pump? That is you checked to see if it was pumping, but did you check to see if it had anything to pump?
--You might have a blocked vacuum line to the gas tank, preventing air from replacing the fuel as it exits and creating a vacuum in the tank.

Thu May 24, 2007 1:40 pm

Another thing to check is the run-on cutoff. It's the 12v wire on the side of the carb that cuts the fuel when the 12v goes away preventing engine run-on. If the wire becomes loose, the engine will die at random times from fuel starvation. That solenoid should click quietly when you make or break the 12v connection.

I had this problem when I first got my car, and I thought the symptoms were pointing to a major problem, but mechanic fixed it in under a minute by crimping the wire tighter.

Thu May 24, 2007 2:12 pm

Does the car die when running, or is it a case where it runs fine but will not start some of the time?
Could a wire related to the ignition system (around the coil and points) be worn and grounding out somewhere? Are any of the coil/ignition wires loose?
What about the wire harness which runs from the generator back to the regulator? In stock form there are a few wires which will kill the engine if they short out. There is also a fuse in there and it can get dirty.
Did you check the section of fuel line which is behind the motor and below/behind the rear seat?

Thu May 24, 2007 2:19 pm

uberautowerks wrote: -You said "no fuel when cranking" Did you also check the feed line to the pump? That is you checked to see if it was pumping, but did you check to see if it had anything to pump?
--You might have a blocked vacuum line to the gas tank, preventing air from replacing the fuel as it exits and creating a vacuum in the tank.
The feed line is clear when it happens. I took the feed line off and blew through it with no problem.
And I also took the gas cap off to see if it had a vacum, and it made no difference.

Thu May 24, 2007 2:22 pm

Maybe your float valve is sticking.

Thu May 24, 2007 2:59 pm

I let the car idle until it died (40 min. or so). Pulled the line from the pump to carb. and had someone turn the engine over. Again no fuel being pumped out.
The I checked the feed line to see if fuel came out, check it fload freely.
I pulle the pump off the car, and again had some turn the engine over. The push rod moved up and down with no problems.
THen I pushed on the lever inside the pump and found no resistance. So I checked the one that I had replaced and it had resistance. While comparing the two, the one that was just on the engine popped and I had resistance with a little fuel that squirted out. So I reinstalled it, and what do ya know the engine started right up.
I'm thinking that when the pump gets hot, it vaper locks.

Fri May 25, 2007 11:54 am

Vapor-lock-type issues can be related to the hoses and fill tubes for the fuel tank.
Besides the hoses that go to the filler tube, there is also a breather hose that goes to a fuel vapor canister. If this get clogged of full of fluid, you can get the symptoms you described.

I had all my filler and tank lines replaced as well as having the canister checked. It made a big difference and now there is no fuel smell with my Thing ever.