I am thinking bad fuel

[LRMAN]

I have rebuilt the carb, replaced the points, coil, condenser, plugs, wires, cap and rotor. Valve lash is good. Have not yet checked compression although I think it is ok.

I used to have to sometimes feather the choke to keep it running. Sometimes it would idle fine and others it would quit when I came to a stop. I would get it home and find it running fine again.

Since doing all this work, the truck has run much better. Now I am finding it not able to idle at all without the choke. I run it for 15 minutes to get it up to temp and when I push the choke in it surges a little and dies. I checked the idle mixture screw and all the linkages and they all seem fine.

I found today that I can adjust the choke(weber) so that it is just at the point where it starts to open the choke butterfly plate. If I even try to open that plate just a little bit, it stalls. Otherwise it runs pretty good.

The fuel is about 2 gallons of year old fuel and 2 gallons of fresh. It has a mechanical pump with an inline filter between it and the carb. When I shake the filter, the fuel turns brown.

Next I will change out the filter, blow out the lines and feed the fuel intake from the pump into a jerry can with fresh fuel.

Any other opinions?

[greasyhandsagain]

how would YOU like to eat two year old food?

brown sounds like rust in the petrol tank...making its way toward your engine.

[badvibes]

brown sounds like rust in the petrol tank...making its way toward your engine.

I agree with greasyhandsagain, crap in the tank making its way towards the carb. Do you have the screen in place on the end of the pick up tube? Blow everything out very well and replace the filter. You might even have to run a piece of flexible wire thru the pick up tube to clear all the crud, I did. Do you use lead fuel additive? I've seen that stuff clog fuel lines/filters but the sediment has more of a reddish tint.

Jeff

[kevkon]

One thing to consider, I just went thru a similar situation with mine and thought I was going crazy. I checked everything and replaced filters, points, coil, condensor, and a few other things. I noticed when using the timing light that the ignition didn't seem to be advancing. After pulling the distributor I found that the mech advance was not working because the weights were binding. I'm use to American distributors where the advance mech is on top, not hidden below like the Lucas. Down below the contact plate the advance can get gummed up and not work and you won't know it.

[LRMAN]

Good point Kevkon but I shouldn't need any advance at idle should I?

My vacuum advance is not connected but I will check the mechanical advance tomorrow.

[willincalgary]

Should check the idle jet on the Weber. Mine clogs fairly frequently with similar symptoms (although not identical). I blow it out with carb cleaner, stick it back in and it idles again. Takes about 30 seconds. Do you use lead substitute in your fuel?

[kevkon]

Why isn't your vacuum advance hooked up? The vacuum advance aids in no/light load conditions such as idling.
In my case the sticking mech advance caused all sorts of problems as it would intermittingly work.

[LRMAN]

Should check the idle jet on the Weber. Mine clogs fairly frequently with similar symptoms (although not identical). I blow it out with carb cleaner, stick it back in and it idles again. Takes about 30 seconds. Do you use lead substitute in your fuel?

I have cleaned the idle jet with no improvement yet. I do not use lead substitute but not sure what may have already been in the tank.


Why isn't your vacuum advance hooked up? The vacuum advance aids in no/light load conditions such as idling.
In my case the sticking mech advance caused all sorts of problems as it would intermittingly work.

I just got this truck and am going through it. I am planning on hooking up the vacuum advance but it was idling fine without it.

[brucejohn]

Hook up the vacuum advance any way.

The hooking up a vacuum gauge pretty much always tells you what is wrong if you know how to read one. If not google. I don't know how I tracked down issues before I learned how to use a vacuum. It will tell you if it's engine, dizzy, or fuel.

The only thing I might try first is the starter fluid leak test.

[Tim Smith]

You might also want to check that there isn't a leak in the intake system. I think* I had similar idle issues once and found the carb was loose from it's base which made it run too lean.

Just a thought.

[LRMAN]

I connected the vacuum advance and still no change. While adjusting the choke, it started idling fine again. I took it for a drive about 1 mile and it continues to idle nicely. I will drive it further later to see if it has any problems.

[LRMAN]

Warmed up the rover today and made a few minor adjustments to the idle speed and mixture. Drove it about 50 miles and it ran great. Idled at every stop without stalling. I got within 2 miles of home and now the idle is too high. I took a turn out of the idle speed screw and it is back to normal. I wonder what the heck is going on. The only thing I did today was add 4 gallons of gasoline. Maybe I have run through all the bad gas and now it likes the new stuff better.

[Tim Smith]

When the idle kicks up, does it sound like it's running richer or poorer? I still thing there might be an intermittent vacuum leak going on but it's just a guess.

[scott]

if it sat long enough maybe the dizzy isn't advancing and returning smoothly. badvibes had a similar situation. we pulled the points and deck, cleaned and lubed the inners and he got a better running truck