Hard to start Hot

[timc930]

Two and an eighth inch-holes? Wow, it's REALLY vented now!



Nice job. This is a well-known issue to me, unfortunately. My issue is always a clogged up sediment screen on the bottom of the fuel pickup tube though it's is essentially the same problem as a bad tank vent. Glad it was an easy fix.

2 holes 1/8 each!!

yeah been running it all day and no problems at all....

Funny thing, i've been fighting this for the last couple of months and pulled the gas cap this summer and it made no difference at all...i just installed a FP regulator and set it at 2.5 lbs since the elect FP puts out 4-7.

[timc930]

Tim,
Great! Glad it was something so easy to fix. I've seen that happen in modern cars with their complicated fuel systems, but not often with Landy's. At least now you have all the jets in the carb clean and a good electric pump in place.

Cheers,

Rob
Bugeye88

Yeah, I think I am good to go!!!

[timc930]

Yeah, I think I am good to go!!!

So Actually I am back to the problem. Drove it today first time since TG week, and after driving for about 15 minutes started loosing power, then it just shut down as if it ran out of fuel. Fuel in the FF, but when I pulled the line off the carb, no pressure. Usually I get a bit of spray. Turn FP on to see if fuel was flowing, and it was. Connected fuel line back up, took gas cap off, and truck fired right up. Turned around to drive home, and after 5 minutes starting acting as if it was not getting enough fuel, would not take full throttle (gas cap still off) so I had to drive slower and slower as if fuel flow was reducing, as if a vacuum was slowly building reducing the fuel that was able to get to the carb, but gas cap was completely off.

Truck act's just like once it's started, there is slow vacuum building, slowly reducing the fuel flow to engine, with eventually preventing fuel from reaching the combustion chamber, but I have the gas cap off so I don't really know where the vacuum could be building.....





So,, just thinking here, when I was driving flat out (approx 60mph) as the truck started to loose power there were one or two very loud backfires out the exhaust, which to me always means to much fuel. I am wondering if I may have just the opposite, with the engine flooding due to sticky needle seat etc etc. Also, when I shut the truck off after a hard run, I always get one large backfire out the exhaust after truck shuts down....

I have pulled the carb apart several times, (and just recently soaked in CC) to check the N&S, with no apparent visual or operational feel of a problem, but mpg has always been low double/high single digits since I have owned this truck....

tim

[o2batsea]

Backfire usually indicates timing is off. If it were me I'd stop throwing love at that carb and order up a new one.

[SafeAirOne]

The engine dying really does sound like a fuel deficit situation. Poor venting is only one cause for a fuel deficit like this. The other cause is a blockage upstream from the fuel pump(s).

Which electric fuel pump do you have? There are filter elements that can get clogged up in the stock Facet fuel pumps that came on 109 wagons:



Re-check the strainer screen on the bottom of the fuel pickup tube in the tank. Every time that my rover exhibits the exact same symptoms you describe, the strainer is plugged up with new debris from my increasingly rusty fuel tank. I generally scrub it with an old toothbrush then blow it out by putting my the nozzle of my blower into the uplift tube hole and gently (at first) blowing OUTWARD, clearing the screen completely.


As for the backfiring...I think that's a different issue. Backfiring out of the EXHAUST is often a leakage issue with the exhaust manifold or downpipe, combined with unburned fuel in the exhaust stream. Backfiring out of the CARB is often an issue with a hot spot somewhere in a cylinder or poor ignition timing or poor valve timing.

What do your spark plugs look like?

[timc930]

The engine dying really does sound like a fuel deficit situation. Poor venting is only one cause for a fuel deficit like this. The other cause is a blockage upstream from the fuel pump(s).

Which electric fuel pump do you have? There are filter elements that can get clogged up in the stock Facet fuel pumps that came on 109 wagons:



Re-check the strainer screen on the bottom of the fuel pickup tube in the tank. Every time that my rover exhibits the exact same symptoms you describe, the strainer is plugged up with new debris from my increasingly rusty fuel tank. I generally scrub it with an old toothbrush then blow it out by putting my the nozzle of my blower into the uplift tube hole and gently (at first) blowing OUTWARD, clearing the screen completely.


As for the backfiring...I think that's a different issue. Backfiring out of the EXHAUST is often a leakage issue with the exhaust manifold or downpipe, combined with unburned fuel in the exhaust stream. Backfiring out of the CARB is often an issue with a hot spot somewhere in a cylinder or poor ignition timing or poor valve timing.

What do your spark plugs look like?

Hi Mark,

No blockages what so ever. I can blow thru all the lines all the way to the carb. The FP is a NAPA Facet type pump. Approx $65 and puts out 4-6lbs. Just purchased it and installed TG week. Pulled the tank line and there is no strainer screen, just a long pipe with open end that sticks down into the tank, unless the pipe slides into a strainer screen. I'll double check that.

I do have an exhaust manifold leak, as there is a broken manifold bolt and I hear a significant exhaust leak when driving.

[timc930]

Backfire usually indicates timing is off. If it were me I'd stop throwing love at that carb and order up a new one.

Yeah I've got a Weber 2bbl and manifold that came with the truck, I amy try that....

tim

[SafeAirOne]

No blockages what so ever. I can blow thru all the lines all the way to the carb.

With the absence of a strainer on the pickup end of the uplift tube in the tank, you've got to wonder where all that junk that's being sucked up is ending up.

The way this problem works is that you would be able to blow all the way through. It's not necessarily that a fuel passage doesn't exist at all, but rather that a large enough passage doesn't exist.

That's why you can run the truck at idle all day long, but soon as you start giving the engine some revs and it starts demanding more fuel, you start to develop a "deficit" of supplied fuel. It starts off slight at first and the fuel pumps can overcome the developing deficit, but sooner or later, the pull of the pumps is not enough to overcome the vacuum between the blockage and the pump to supply the engine with all the fuel it demands.

This is evidenced by the fact that the engine RPM slowly drops off until, finally, either there is NO fuel flow to the engine and it dies or it operates only up to a level where the available fuel supply to the carb is sufficient, such as at idle.

Imagine sucking soda through a McDonald's straw with a piece of ice blocking the bottom. You can get some soda through the straw, but if you really suck on it, a real vacuum develops and the straw collapses, leaving you thirsty.

I'm not saying that this is definitely your issue, but if it were me and I was certain that it's a fuel supply issue and not an ignition issue, I'd probably swing down to my local auto parts store and buy a length of fuel hose and the fittings to bypass the existing fuel line from the tank to the fuel pump and then figure out how to clean the crud off the inside of the fuel uplift tube and hook it up and test that out for a while to see if the problem goes away.

Speaking of ice, did you check for carb icing when it conks out on you? I doubt this is possible with the carb sitting right over the exhaust manifold, but you never know unless you check.

[timc930]

With the absence of a strainer on the pickup end of the uplift tube in the tank, you've got to wonder where all that junk that's being sucked up is ending up.

The way this problem works is that you would be able to blow all the way through. It's not necessarily that a fuel passage doesn't exist at all, but rather that a large enough passage doesn't exist.

That's why you can run the truck at idle all day long, but soon as you start giving the engine some revs and it starts demanding more fuel, you start to develop a "deficit" of supplied fuel. It starts off slight at first and the fuel pumps can overcome the developing deficit, but sooner or later, the pull of the pumps is not enough to overcome the vacuum between the blockage and the pump to supply the engine with all the fuel it demands.

This is evidenced by the fact that the engine RPM slowly drops off until, finally, either there is NO fuel flow to the engine and it dies or it operates only up to a level where the available fuel supply to the carb is sufficient, such as at idle.

Imagine sucking soda through a McDonald's straw with a piece of ice blocking the bottom. You can get some soda through the straw, but if you really suck on it, a real vacuum develops and the straw collapses, leaving you thirsty.

I'm not saying that this is definitely your issue, but if it were me and I was certain that it's a fuel supply issue and not an ignition issue, I'd probably swing down to my local auto parts store and buy a length of fuel hose and the fittings to bypass the existing fuel line from the tank to the fuel pump and then figure out how to clean the crud off the inside of the fuel uplift tube and hook it up and test that out for a while to see if the problem goes away.

Speaking of ice, did you check for carb icing when it conks out on you? I doubt this is possible with the carb sitting right over the exhaust manifold, but you never know unless you check.

Good point. I'll bypass the existing line and see what happens. Yeah no icing at all at the carb...

tim

[timc930]

So in the meantime, I just replaced the plugs (autolite with NGK) and drove for an hour or so today with zero problems. I have not yet bypassed the existing fuel line, but interesting that replacing the plugs gave this result....

itm