More fuel issues, i guess?

[agwrangler]

I have been having issues with the A2 for a while and have spent a lot of time trying to research the issue, both here and calling people, and I am at a loss. While running and driving along, out of nowhere it will just sound like it is sputtering and going to die. If i leave it in gear, it will obviously die. If I throw it into neutral and do nothing else, it will die. If I throw it in neutral, and put the gas pedal on the floor, it will keep running, but at a bare minimum. It just sputters, and glogs, and tries to die, then from out of nowhere, it just comes right back like nothing happened, running like a raped ape, until the next time when it does the same thing. I might keep it floored and running for 4 minutes waiting for it to catch up, or it might just be 10 seconds. Lastly, it slightly bucks when driving. I especially notice it in 3rd gear. Nothing BAD, but I can definitely tell.
So this weekend i put in Autolite 2245 spark plugs, replaced spark plug wires with NOS, put in an NOS coil, and put in a rebuilt carb. When I went to remove the screw in fuel filter on the carb, it shot fuel EVERYWHERE, and I thought that was a little odd for that carb to have that much pressure on it. So I put in the rebuild carb, and a new filter, and put everything back together. SAME story, nothing changed. When i went to swap back out and put the original rebuild carb back on, there was the same amount of pressure on the carb. I dont ever seem to remember there being that kind of pressure any other time i was changing carbs on the MUTT.
Is the fuel pump over pumping?! I have never heard of that. The only things left to change are the PCV and the fuel pump. Just so wierd that it will run great until out of nowhere it has this issue, then once it clears up, its fine again.

Any ideas?? I am freaking stumped.

[Mark]

I try it without the inline filter installed

[acudanut]

I try it without the inline filter installed

I don't think the filter has anything to do with, but that is just my lousy 2 cents. Can you find a fuel pressure gauge ?

[rickf]

Sounds like it may be vapor locking, what carb is on it? If it is a 13660 does it have the return line hooked up? It is not likely that overpressure would cause the problem you are describing. I would definitely check the pressure just to be sure it is less than 4.5-5lbs. max. That kind of pressure is usually built up when gas boils between the fuel pump and the carb, this was why they added in the vapor return orifice to the later carbs. What you are describing sounds a lot like a failing coil or ignition module. Especially if it happens again not long after the first episode and shorter intervals each time.

[m3a1]

Ok, so you have a fuel delivery problem which culminates in higher pressure than normal at the carb. Is yours and emission system or earlier? What kind of pump are you running?

[agwrangler]

TJ, I am running an off the shelf filter from NAPA. The carb is the pre-emissions type with the adjustment screw. I have tried adjusting the screw to make it go away and that didnt help at all.
It isn't a coil issue, as I changed and put in an NOS one, and the results are identical. And it doesnt matter how hot or long the engine has been running, there is no pattern to it. (ignition module maybe?? I didnt change that). It is points type.

[m3a1]

Well, actually my statement should have been something other than higher than normal pressure at the carb (which isn't really necessarily the case) but let's just say it's "holding pressure" right?

[rickf]

So you are running points ignition, that eliminates an ignition module. NOS coil does not mean it is not bad but let's assume for now it isn't. You are running a "pre-emissions carb" that did not answer my question as to whether it is a 13660 but I will assume it is not. When I rebuild a 13660 I put an external idle adjustment screw in them. So I will guess it is a 12848 or a 13841, neither of which has the vapor return. NOTE that I am NOT using the term FUEL RETURN LINE!!! It is NOT a fuel return line. It is a vapor return line. If you look at the size of the orifice in the fitting you will understand why I say that. Next question, does your fuel line run from the pump in the stock location away from the heater hose and radiator hose? What I think is happening with these old pumps is that the diaphragm is getting old and stiff from the alcohol in the gas and just the fact that it is stiff it does not stretch when the cam pushes it up and it pulls itself back down in addition to the spring pushing it down. There is a place in Mass. or NH. That is rebuilding these pumps using all new parts. I will have to try to find the name again.

Found it

http://www.then-now-auto.com/fuel-pumps/

[agwrangler]

rick, I will have to look and see which model is on it. I only run avgas in my MV's so there is no issue with the pump being too old or bad in this particular case (though i know that does happen with regular fuel over time). Also, this fuel pump isn't old enough to be worn out. It was working great and I didnt have this issue for a while.
As for the line, I actually was considering rerouting my fuel line as far out from the engine and radiator hose as possible to help with the cooling. I DID think that the carb was DAMN hot to the touch, which i thought was maybe a little odd. I will have to look at the fuel vapor line and see whats going on there.
Asfor the coil, if it wasnt showing the EXACT same symptoms, (hot or cold engine, no pattern, etc) being able to restart immediately after it dies, then i would say it could still be coil.

[m3a1]

I can't wait to find out what this is. The business with there being no apparent rhyme or reason to the occurrence is going to be key to this. This is one of the reasons I would like you to just let it idle and make observations. In doing so you remove a lot of variables and it lets you watch the fuel in the clear plastic fuel filter.

While you're at it, make a physical inspection of your ignition. A bad rotor, meaning one that is sloppy on the shaft could produce such circumstances (ask me how I know) and the temporary on-the-road solution you have described may be in error, eh? In essence you may think one thing is happening when it may be quite another. I'd suggest you look it over just to rule out as much as possible.

Don't want to sound like I'm making busy work for you either but if you have the means, maybe a compression test and a vacuum test is in order and if you don't have test kits, Harbor Freight has them at dang near giveaway prices.

Cheers,
TJ

[m3a1]

By the way, your distributor IS tight, right? No loose or missing retaining bolt?

[agwrangler]

Engine is still fairly new from rebuild. Only probably 500 miles on it, so I doubt its something like that internally.

I messed with distributor yesterday a lot, checked to see if it was tight, anything burned up or missing, and all looked acceptable.

*throws hands in the air*

I just dunno!!!!!

[kmam]

There are many on this forum far more knowledgeable than me but sometimes an ignoramus can come up with something useful...

I had strange problems with my LandRover Series that had a points ignition system. Turned out to be the springs on the weights controlling advance. Now the symptoms were not identical to yours but did have some similarities and it may be worth checking that they are allowing the distributor to advance and return normally.

Good luck and sympathy.

Howard

[m3a1]

Keep the faith. Every time you check one thing and rule it out you are one step closer.

[svramselaar]

hi

if the condenser from the ignition has go bad it give the same problem
it like`s if the carburator is not ok it idels bud no power at higher revs

wen the springs at the ignition go bad the timing go wrong and the MUTT go bad
i have now 3 engine`s with the spring problem repaird 2x mutt and 1x m38a1

george