Hard to start Hot

[timc930]

Having a Hard to start hot issue, so today I bypassed the mech pump and installed a Facet Electric Pump, pulled the carb, took apart, let soak in carb cleaner for a couple hours then reassembled, installed the carb and truck fired right up. I let it idle for around 30 minutes to get good and hot, shut it down, waited five minutes and will not restart. If I hold my hand over the carb body while someone is cranking, I can usually get it to start. Also replaced the coil as well. Weber 34ICH Carb.

[SafeAirOne]

Well...if I were sure it's a carb problem, I'd start by looking for either an air (vacuum) leak at temperature or a fuel flow restriction at temperature, or, less likely but possible I suppose, a vapor lock issue.

Take this with a grain of salt though, since I don't use carburetors myself.

[timc930]

This may be a feed issue, as it fired right up this morning, let it run, shut it down, then it would immediately restart. Once I waited 10 minutes, it would not. I could hear the Elect FP running trying to reprime (pump is loud until it has it's prime), it wold not reprime until I removed the fuel line form the carb, then it began to flow. Going to check the lines coming from the tank.

Regardless of the above, there was fuel in the carb bowl, so it should be starting warm/hot, that's what is puzzling.

[timc930]

So there is nothing restricting the fuel flow to the carb. Looked in tank, very clean. Blew threw the lines. Today, I let the car idle for about 40 minutes and it just shut down. Fuel pump kept running (electric and wired to ign switch) but was very loud because it was not pumping fuel. I have no idea what is could cause an elect pump to all of a sudden loose the ability to pump fuel. Once car cooled off it fired up on first crank.

The car acts as if once the engine gets hot, the fuel becomes a vapor, and the elect fuel pump and the carb are unable to function until the engine cools.

[SafeAirOne]

It sounds like the fuel pump is being starved of fuel. Is your tank properly vented? Does the sound of the starved pump change when you remove the fuel filler cap?

Is the sediment screen on the bottom of the fuel pickup tube clean? Is there an internal sediment screen in the electric fuel pump?

[timc930]

It sounds like the fuel pump is being starved of fuel. Is your tank properly vented? Does the sound of the starved pump change when you remove the fuel filler cap?

Is the sediment screen on the bottom of the fuel pickup tube clean? Is there an internal sediment screen in the electric fuel pump?

No sediment blockage anywhere in system, carb pulled apart and cleaned this week, tank clean, all fuel filters perfectly clear with no sediment what so ever.

Tank is not vented, and I tried removing the cap several months ago when I was working this, but that was with the mechanical pump. But you are exactly right, it does act as if there is vacuum pulling against the fuel flow....

How should the tank be properly vented?

[Les Parker]

You could have a bad fuel cap. It should have a small hole for venting on IIa's and a vent valve on the Series III.
Try it will the filler cap removed.

[timc930]

Looks like it was a problem with venting, creating a vacuum all the way to the carb, as there was fuel in the bowl and it still would not start. Removed the gas cap, so far so good. I have drilled 2 1/8 holes in the underside of the cap....

Been running it all morning, getting hot, shutting down, waiting 5-10 and it has fired right up each time. Drove it a few miles did good. We'll see how it goes....

tim

[bugeye88]

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

[SafeAirOne]

I have drilled 2 1/8 holes in the underside of the cap....

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.

[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:

https://farm9.staticflickr.com/8649/15889007200_ff7d4197f1_z.jpg

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:

https://farm9.staticflickr.com/8649/15889007200_ff7d4197f1_z.jpg

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

[SafeAirOne]

What did the old plugs tell you about what's going on?

[timc930]

What did the old plugs tell you about what's going on?

Most were rich, one was brown. Not sure how this would cause the truck to feel like it was loosing power, then eventually shut down, unless the plugs were just fowling out. Drove it for a while tonight with the new plugs and so far it's running fine, but I am sure I still have a problem.

[bugeye88]

To quote Alice "things are getting curiouser and curiouser"..... Might as well replace points and condenser while your at it. Maybe coil as well to give the whole ignition a kick in the pants. My money was on a fuel supply issue. Did you ever drain the tank to see any crud in the tank? screen on the fuel pick-up?

Cheers,
Rob
Bugeye88

[timc930]

To quote Alice "things are getting curiouser and curiouser"..... Might as well replace points and condenser while your at it. Maybe coil as well to give the whole ignition a kick in the pants. My money was on a fuel supply issue. Did you ever drain the tank to see any crud in the tank? screen on the fuel pick-up?

Cheers,
Rob
Bugeye88

So I replaced the Cap, Rotor, Points, Condensor, Wires several months ago but did not replace the plugs until the other day. All fuel lines are clean, and tank is spotless on inside. Fuel filters are also spotless. Truck has been running fine since I replaced the plugs, well so far....

edit: Just got back from another drive to the beach with the dogs and truck ran great. When I pulled the old plugs three were black, one was almost normal. I know the truck is running rich as the mpg is lower double upper single digits, so the only thing I can think of at this point is the truck was fouling out, just not sure why it was able to start after sitting....I am reaching at this point but still working on it...

tim

[bugeye88]

Tim,

Right, so it was either a bad plug, fowled plugs in general, plus a carb that is not jetted properly or other carby problems like clogged jets. Have you gone through the carb recently? Also carb air filter, especially if its the oil bath type should be cleaned. Keep plugging you're making ground.

Cheers
Rob

[timc930]

Tim,

Right, so it was either a bad plug, fowled plugs in general, plus a carb that is not jetted properly or other carby problems like clogged jets. Have you gone through the carb recently? Also carb air filter, especially if its the oil bath type should be cleaned. Keep plugging you're making ground.

Cheers
Rob

Yeah pulled the carb apart over TG week, soaked in carb cleaner and reassembled. Checked needle and seat as well. Could be wrong jets though as it appears to run very rich, but it has the stock weber 34 on it...

have not touched the oil bath yet....

tim

[SafeAirOne]

One final thought---on an occasion or two, I've had the cloth on the inside of the air intake hose between the air filter and the..well, it'd be the carb in your case...de-laminate and collapse into airstream, blocking the airflow to the engine. In my case, the power loss combined with the plume of black smoke out of the tailpipe were dead giveaways as to what was going on.

Chances it, this is not your problem, but it can be intermittent, causes a rich mixture and a power loss.

[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.

So as I stated earlier, it's running 100% better, but I am still way rich. I moved the truck, then pulled the intake and exhaust manifolds off to replace bad exhaust gasket, and there was fuel pooled up in each of the intake ports on the head. Plugs are black again after driving less than 100 miles so I have ordered a new weber carb.

[bugeye88]

Tim,
Hope the new carb does the trick. Be sure to order it with the correct jets for you altitude. Most carb sales places will do that for you, and they are usually good. Since I remember you are running a dual inlet carb, I assume it is the Weber 35 DGV. I have run one of these on a Series 111 and it was quite good. But this is a lot of carb for these 2.25 engines and can run rich easily if the jets are off even a bit. The single inlet 34 ICT Webber I feel is a better carb for our applications, and is what I am running on my 68 Bugeye. It provides better intake velocity and is easier to set up and has good linear power curve. The other carb I like and have used is the Rochester GM carb. Again, a lot of carb for our engines but they are quite reliable and have linear power curve with a bit more top end power. The 34ICT has better low end characteristics. Let us know how it goes.



Cheers,

Rob
Bugeye88

[timc930]

Hi Rob, I was running a 34ICH, and just ordered a new one from our host, should be here tomorrow. I do have a progressive 2bbl Weber and matching intake manifold that came with the truck, but I just did not want to go to all the trouble of jetting it properly to run with the little 2.25, as I have no idea where to start, or what size engine the carb was jetted to work with. Years ago I had a 1.7 litre 914 and I installed one of the Weber progressive 2bbl carb's, but it came properly jetted. I am hopping that RN knows the proper jets to work with the 2.25 and as such the carb should come properly jetted.

Right now I just want it to run right, with decent mpg!

tim

[bugeye88]

Hi Tim,

I also had a 914. Great little car. Mine was a 1974 2.0. I never made the jump to carbs, but if I had, I would have used Weber DCOE's.
Good your using a 34 ICH as I mentioned before. intake velocity of a smaller intake make for good lower end torque and I've found the carb works OK at the upper end also. As for jetting, altitude is a key factor. Post your elevation and ask folks here online what jetting they have on their Weber 34 ICH for that altitude. There should be several with similar set ups as the Weber is a popular Carby. Soldier on!

Cheers,

Rob
Bugeye88

[timc930]

Thanks Rob. I went thru 3 914's, 2 72's and 74 in the late 70's and early 80's. I ended up leaving the FI on the 74. Then I jumped into the 911's, 2 71's, a 77 during the 80's and 90's, and finally a 930 for the last 8 years, it's a keeper. I drove it from SC up to Maine a few years ago, then over to Vermont to meet Arthur P at RN. Amazing road car! Bought it with 34K in 04, it now has just under 140K on it. Most reliable car I've ever owned. Been a Porsche freak since the late 70's!

OK, back to LR's!

So I have the stock air cleaner on the series, that has a rubber hose coming off of the air cleaner, then a metal elbow that curves around to connect to the carb via a short 2" host adapter. I and ordered this part (PLC375) thinking it would connect the "elbow" onto the carb. It fits on the carb, but does not fit on the metal elbow. What do you or others use for this connection on the Weber?

tim

[bugeye88]

Tim,
Im using a similar 2 or 3 inch tall rubber hose type fitting for the connection of the metal elbow and the carby. Requires a good hose clamp to keep it attached to the carb and the elbow. I have a K+N cone filter at the end of the metal elbow. K+N's have low restriction if maintained properly and are light. The oil bath is good for very dusty/dirty conditions, but restrictive. Let me know how the new carb works!

Cheers,
Rob
Bugeye88

[siiirhd88]

There are two or three different sized carb "elbows ". The Weber I had used an adapter around the carb top to increase the diameter to match the hose. There are also several styles of elbows, with attached tubes for the various crancase vent system connections.

One of my trucks used a sleeve of rubber tubing inside the hose to fit onto the carb. It wasn't very secure.

Bob

[timc930]

Apparently my truck came with a Solex, which has the very large opening on the elbow>>>Carb....The rubber adapter I purchased from RN was for a Zenith/Weber....At least that's what the RN guy told me today. I need a hose with an ID that goes from 2.5 down to 2 1/4...

tim

[siiirhd88]

PM sent.

You could try the plumbing supply section of the bigger home stores, as they have sections of rubber tube used to connect drain piping. Weber did supply an adapter ring on one of my carbs, but it is long gone.

Bob