109 exmod gremlins are back

[siii8873]

well he's back. Truck has run flawlessly since replacing alternator about 3 weeks ago in NC. Well today some old issues raised their head again. First went to start truck, turned over would not fire. Has not done this for about a month. I poured a little gas in carb it fired and started. Drove to work, shut it off, started fine. Drove about 1.5 hrs to a job site, stopped and got gas on way started fine. While at site had to move the truck, it started drove about 50yds, it stalled and would not start. A little fuel, took 2 times this time, ran fine. stayed about another hour and went to start it no go. Took many times to get it going this time. Once it starts it runs great! Things I have worked on/replaced in last month, New plugs,points condensed, cap,rotor, wires, fuel pump.
One other item. After I was on the road for about an hour my turn signals stopped working. They started working again when I started home, quit again for a while after driving for a while, then worked again. Not sure if it's related. This one has me stumped. I'm thinking it could be electrical but what is the fuel doing to make it run if so? Any thoughts?

[bkreutz]

Could be a fuel pump issue. Perhaps the fuel is siphoning back out of the carb after it sits for a while, then when you crank it, you're not getting enough pump action (slow cranking speed), when you add fuel, it starts and the pump is pumping much faster. Could be a loss of spark too, but adding fuel to the carb wouldn't have any effect.

[siii8873]

Forgot to mention I replaced the fuel pump also. I also thought it was a syphoning problem after sitting when this was going on a month ago or so. Then it seemed to happen only when it sat for a while. Today it did it after sitting for less than an hour. It also started drove for about 50yrds stalled and wouldn't start.
The carb is a weber 34Ich, are these symptoms of a dirty weber?

[bkreutz]

IMO a new pump is not necessarily a good pump (that's why they have warranty's) One quick way to check if the float bowl is empty is look down the throat and operate the linkage by hand, if there's fuel in the bowl the accelerator jets will squirt fuel. Could be something plugging up the carb internally, but if the carb fails the "squirt test" I'd be looking at fuel supply.

[hughwilton]

I got a couple of bad fuel pumps in a row. I now have an electric fuel pump & have not had any fuel issues for over 4 years. (I'm running a Rochester).

[siii8873]

what confuses me about this is after it starts it runs great. No hesitation great power, no problems. Maybe I'm all wet but if it were a fuel supply problem wouldn't I have operation problems when running.

[o2batsea]

Original carb? If so it's probably time for a new one. Rebuilding is a waste of time. You might also consider fuel injection.

[jac04]

^^He stated he's running a 34ICH, so it's not the original carb.
Fuel injection? Really? Let's try to offer him some more feasible solutions to his problem.

Back to the fuel problem.....
Are you still running the twin tanks with the changeover valve? Check out the valve - sometimes they can allow air to enter the fuel system without showing signs of leaking.

One other item. After I was on the road for about an hour my turn signals stopped working. They started working again when I started home, quit again for a while after driving for a while, then worked again. Not sure if it's related. This one has me stumped. I'm thinking it could be electrical but what is the fuel doing to make it run if so? Any thoughts?

I had the same issue with my Lightweight signals. Turned out to be a broken connection on the flasher relay circuit board. A quick touch with the soldering iron fixed it.

[bkreutz]

what confuses me about this is after it starts it runs great. No hesitation great power, no problems. Maybe I'm all wet but if it were a fuel supply problem wouldn't I have operation problems when running.

Not necessarily, think about the speed of the fuel pump while cranking and then think about the speed while idling, big difference. Sometimes (notice I said sometimes) when a pump is starting to fail, it will not pump at slow speeds but at a faster speed it will pump enough to mask any problems. May be wrong, but I've seen this scenario before. Keep plugging away, you'll find it, after all it's only a machine.

[singingcamel]

i have a hunch its in the carb,dumping the fuel down it is just like priming a pump..Stuck float , bad accelerator pump..change your fuel filter .
www.singingcamel.com

[siii8873]

I have a spare, with a service kit rebuilt / cleaned 34ich with correct jetting and thinking just change it and wait and see............... Fairly quick and easy.
I did change the filters a short time ago including the one at the carb inlet. I'm leaning toward this being the issue also.
Just always hear from everyone fool with carb last.

[o2batsea]

^^He stated he's running a 34ICH, so it's not the original carb.
Fuel injection? Really? Let's try to offer him some more feasible solutions to his problem.

Back to the fuel problem.....
Are you still running the twin tanks with the changeover valve? Check out the valve - sometimes they can allow air to enter the fuel system without showing signs of leaking.


I had the same issue with my Lightweight signals. Turned out to be a broken connection on the flasher relay circuit board. A quick touch with the soldering iron fixed it.

Yes, genius, fuel injection. Don't be scared of it.

[jac04]

^^Thank you for referring to me by my proper title, although the "G" should be capitalized. Anyhow, I (and quite a few other people here) would be interested in your 2.25 fuel injection set-up. Feel free to start another thread on the subject.

Given the problem at hand, suggesting a custom FI installation as a solution is just a little off target, don't you think? And suggesting that an original carb be discarded & replaced just because "it's time for a new one"? To each their own I guess.

[SafeAirOne]

Anyhow, I (and quite a few other people here) would be interested in your 2.25 fuel injection set-up.

There are quite a few 2.25's out there with factory fuel injection. My 2.5 is fuel injected.

[daveb]

really hard to make a meaningful diagnosis without more information. when the truck wont start, can you check to see what other things are working? That might help to rule out an electrical problem. it does sound a bit too intermittent to be a fueling issue. Check your ignition switch and fusebox.