Dead on side of the road.

[Cutter]

As I await AAA, i thought I'd start my thread on discovering the issues. Took a drive (15mi or so)this afternoon with my wife and daughter and on the way home on the highway it started running rough, to the point it was lurching. I pulled off and made it to a parking lot. Engine wouldn't stay running, so I did a quick look over and everything seems ok. Got it to start up again and running consistently enough to tell that it seemed to be not firing on one or more cylinders. Decided to take it the rest of the way home on local roads once I checked all the plugs and dizzy. It made it 90% of the way there and seemed to be running ok, but then started sputtering at a light.

Here's the thing that is worrying me- there's a layer of oily soot on the right side of the motor- ESP the carb that I hadn't noticed before- could be blow back? Or something worse? Not sure but it looks like there's a solid accumulation around the head gasket area.
Vacuum gauge reads fine, seems to have ample amount of fuel coming in, temp is ok, voltmeter reads fine.

Just got off the tow truck and it started up again but didn't make it into the garage. So it seems to recover a small amount given some time, but not for long. Any thoughts?

[SafeAirOne]

If it runs fine for a while then progressively deteriorates till it won't run anymore, then after sitting a couple of hours, begins to run fine again till the cycle begins all over again, then I'd check for a vacuum developing in the fuel system upstream of the fuel pump. This vacuum is caused by some sort of blockage.

This could be caused by a clogged vent in the fuel cap, clogged sediment screen on the bottom of the fuel pickup tube or some other restriction to the fuel supply.

[Apis Mellifera]

Sounds like a clogged fuel filter to me. Will it idle ok, then misfire once you start moving?

[Cutter]

it will idle, yes, and dies upon giving any gas. If it is a simple as something clogging the fuel delivery then I am soo happy. This soot is freaking me out though.

[Apis Mellifera]

I'd go ahead and throw a new fuel filter on it then. The same symptoms plagued my MGA and one new engine later, I found the clogged fuel filter that started it all.

If you think it's a vacuum leak, start the engine, then spray some WD40 or brief shots of spray ether onto the manifold, distributor, brake servo and see if the idle changes.

[siii8873]

try running the truck with the fuel filler cap off. I had these exact symptoms and it was traced back to the cap. I had lost my original one and the replacement sealed so well a vacuum developed in the tank that the fuel pump could not overcome.

[Cutter]

Well I pulled the fuel pump filter basket, inline filter ahead of the carb and the fuel cap, ran the motor for 30 minutes in the driveway and it seemed fine. Rechecked that I was getting spark and adjusted the timing for the hell of it. I then drove around the block at a good clip for a few laps and I could start to detect a stutter when accelerating from first but nothing as intense as before. I ran out of free time so I had to retreat back to the house to start working, but I'm wondering what is next. I did drop the fuel tank a few months ago to install a hitch- not wild about draining the liquid gold in it, but what would one do to make sure there's no obstruction back there?

I think I can rule out a vacuum leak- I watched my gauge the whole time and its is healthy, no response on stutter either.

[SafeAirOne]

Presumably you have a rear-mounted fuel tank. I know the station wagon has 2 small hatches in the tub floor to access the fuel tank plumbing and fuel sender. Does your regular have these small doors in the floor of the bed?

If so, just pop off the one above the fuel sender and pull the sender/pickup tube and check the screen and the feed line for obstructions. I usually scrub the pickup screen with a toothbrush to get the junk off.

Also, if yours is a 6-cylinder, it should have an electric boost pump mounted on the chassis below the right-hand door. Apparently Land Rover felt the 6-cylinder needed a boost pump to assist the regular lift pump in supplying the thirsty 2.6 with enough fuel at all engine RPMs, so yours may have failed if you have one. I think there's also an internal fuel filter in these pumps. It's a common pump where the ends come off with a twist IIRC.

[Cutter]

Presumably you have a rear-mounted fuel tank. I know the station wagon has 2 small hatches in the tub floor to access the fuel tank plumbing and fuel sender. Does your regular have these small doors in the floor of the bed?

If so, just pop off the one above the fuel sender and pull the sender/pickup tube and check the screen and the feed line for obstructions. I usually scrub the pickup screen with a toothbrush to get the junk off.

Ok, So no need to drain- yes it has these, I got the screws unseized when I dropped the tank a few months ago. I'll do this tonight. Thanks.

Also, if yours is a 6-cylinder, it should have an electric boost pump mounted on the chassis below the right-hand door. Apparently Land Rover felt the 6-cylinder needed a boost pump to assist the regular lift pump in supplying the thirsty 2.6 with enough fuel at all engine RPMs, so yours may have failed if you have one. I think there's also an internal fuel filter in these pumps. It's a common pump where the ends come off with a twist IIRC.

Yep, I check that- its pumping strong, and thats the basket filter I cleaned. I re-found that someone installed an inline filter mounted to the frame next to it that isn't hooked up. Seems like overkill but I don't know this trucks early life other than it was Swiss and someone had curtains in the back. If I was to hook it up, seems like I would want it before the pump.

[Cutter]

Pulled the tank pickup tube, filter was clean as a whistle. Pulled the carb, checked the floats, cleaned it up and everything seems in order. I'm not sure my next move- the fuel pump checks out ok but I suppose I could replace. The strange things is now the only time I can get it to stutter is when I start up from a stop. Doesn't seem like the pump would be at fault as it would be more likely to stutter when I'm going faster due to starvation.

Any ideas on what to check out next?

[singingcamel]

I would adjust clean points, check your rotor and dizzy cap..Check all the low tension leads , make sure their on tight..

[bkreutz]

A faulty condenser can give you those symptoms too. I first found this out about 40 years ago after replacing fuel pump(s), rebuilding carb(s). I was convinced beyond all doubt that it was a fuel problem. Finally changed the condenser as a WAG and everything was good. I've seen the same thing a number of times since. More so in recent years as the quality of ignition parts seem to have plummeted.

[Cutter]

I had a rotor explode a while back, I replaced it. I just swapped out the dizzy cap with a spare and the new rotor exploded- Had a backup of that as well so I swapped in a different cap(had a box full from PO) and it seems ok. What is the story on wear of the contacts in the cap, how do you know when to swap it? The cap that broke the rotor had a lot of exposed metal, the one I took off and the final replacement did not. I have a new set of points and condenser but both on the truck now are under 2 years old and points to be operating fine. Maybe that doesn't matter. The cables are all under 4 years old and I've broke down and cleaned-oiled the dizzy internals a few months ago.

Once it was running I had my first dieseling on shut off ever. Didn't happen again after a few attempts.

[Cutter]

Replaced the points and condenser with a pertronix, and it is better than ever! Thanks everyone for walking me through things.

[ACP30470]

Did you try checking the vacuum advance on your distributor? A leak in the line could cause similar symptoms.