Lightweight won't start

[B-Red]

I have been trying to start my lightweight without much luck. The starter kicks in but the engine does not fire up.
It's full of gas.
I checked the distributed cab and spark plug wiring, looks alright.
I have a wet air filter, so not sure how to spray engine starter in it.

Any ideas of how to trouble shoot this?

[camo388]

If the LWT has been sitting for some time the carburetor may be dry.  Until the engine is running, the mechanical pump will not get fuel to the carb.  There should be a lever on the fuel pump so you can manually pump fuel to the carb.  If you loosen (or remove), the fuel line at the carb, you will be able to see when the fuel is getting to the carb.  If you take the line right off the carb, catch the fuel in a container as you don't want gas all over the place.  Re-tighten or replace fuel line and do a few more pumps so that carb bowl is full.  Now turn engine over and it should start.  If still not starting, remove the air intake elbow and drip in a small amount of fuel and then turn over engine.  You want to avoid dripping in gas as engine is being turned over as a flash back can happen and flame will come out the top of carb.  Open gas and a flame are not good outside the engine.  :o
Have you plugged in block heater or been able to warm engine before trying to start?  A warm engine, (and oil), will allow engine to turn easier and faster, making starting easier.  I would suggest even a small space heater set under the oil pan will warm the engine bay.  You would need to shield the heater from drafts to get better results so a blanket covering the whole engine bay, right down the the ground, would be a big help.  Unplug and remove heater before doing anything with the gas.  Here again, open gas and a flame/ heat source is not recommended.
I would avoid using a starter fluid spray or use very very little as a last resort.  It ignites very easily and may drive the engine backwards if it ignites before Top Dead Center.

Good luck.

[Red90]

I assume you are using the choke? And there is gas?  Fuel select valve on a full tank?

Spark and gas is what you check for.

Check for spark.  Pull a plug and with gloves on hold the body to something grounded.  Crank the engine and see if you get spark.

Gas.  See Bruce's advice above.  You can just crank and see if you get fuel.

If either test fails, you then troubleshoot that system.

[B-Red]

Thank you guys. I primed the mechanical pump 40 times. It worked like a charm. Forgot that Thor Petroleum engine has one. I usually do it on the 200Tdi Defendr.

She is wormed up and am ready for a nice ride.

Cheers

[B-Red]

Well. Two years since my last post and am back to square one. Abdu and I worked on the Lightweight to start it up. Batteries are fully charged. Engine turns with starter but does not catch. We disconnected the fuel line at the pump and tried primeing it. Nothing came out. We put gas in the. ARB. About table spoon. Engine worked then died after it used the small gas. I checked and cleaned the fuel selector. Nothing unusual there. Checked the four fuses in the steering wheel. All good. Not sure what else to investigate.

Any input would be greatly appreciated.

Cheers. Emad

[Trevor]

Are you getting spark?

[B-Red]

Yes Trevor. The engine started properly when we added fuel in the carb. I am suspecting the fuel tank switch selector. I was not able to identify what the wires controlled

[Red90]

Wires for the fuel selector?  The stock selector is a manual valve.  If it has been modified, you would need to investigate what was done.  Just blow back through the fuel line from the lift pump inlet to see if it is clear into the tank.

Another possible problem is that the lift pump may be "on the cam".  You need to turn the engine a bit so that the lever on the pump is not held up by the camshaft for the manual lever to work.  If that is not it, the lift pump may be dead and need to be overhauled or replaced.  It all comes apart and is meant to be serviced.  Do you have the workshop manual?

[B-Red]

The vehicle is 24 volt. The selector looks original. I have the shop manual at the office. I will review it tomorrow.

The pump lifter looks mechanical. I did not see any wires to it.

[Matt H]

Could be Sediment in the fuel pickup? It's just a pipe that opens up at the bottom of fuel tank. Very common that these plug up in units that are seldom used. If nothing else appears to be causing it I'd check there.

If it turns out to be dirt/sediment in the tank it will need to come out and be properly cleaned. You can blow out the line in an pinch to get you home but it will just plug up again eventually. Been there, done that!  ;D

[binch]

Yup, sounds like a fuel supply problem doesn't it.   John and Matt had some good suggestions there.    Give them a try.  I doubt it's anything electrical on your LWT.  We are all waiting to hear how you make out  ;)

[Already a Rover]

On hot days and highway runs, I sometimes I get a vapour lock and priming via the fool pump doesn't do it.  Pouring gas in does, but I may have to do it a couple of times to exorcise the demons.  Old fuel in the tank, but not in the jerry can? 

I often marvel that mine ever works at all....

J

[camo388]

Emad, you are lucky with the LWT fuel tanks in that you can take out filler neck and have a good look inside.  Should be able to see anything returning to tank if you blow out the fuel lines.  Big enough hole to even get a rag in there and wipe out any old fuel, dirt, etc.  If there was some time since you last ran the LWT and you did not drain tank and run engine till all fuel was used up in the carburetor, then the gas will evaporate over time and create a varnish.  This varnish will gum up the whole fuel system. 
It is the same with your lawn mower in the fall, drain the fuel and run engine till it stops.  Come spring refill with gas and it usually starts once carb is full of new gas.
Good luck and tells us how you got it going.

[RossM]

On hot days and highway runs, I sometimes I get a vapour lock and priming via the fool pump doesn't do it.  Pouring gas in does, but I may have to do it a couple of times to exorcise the demons.  Old fuel in the tank, but not in the jerry can? 

I often marvel that mine ever works at all....

J

Jim
I am also getting what appears to be vapour lock in this hot weather, it has never happened in 27 years of running. I put in a new fuel pump, no improvement. The 2.25 is running hotter than normal, drained and refilled the rad,  no improvement. Water pump sounds like it is making more noise than usual. Will look at that next. Reroute the gas lines and a Carb rebuild. The issues are cascading.
Great fun until the bills come in!
Ross


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[B-Red]

So we did some good progress today. We dismantled the fuel line from the pump back to the two tank switch valve. It turned out to be mechanical. The wire leads were for the fuel gauge. Air bubbles can be seen in each tank as we blow in the fuel line turning the selector to each tank. When we placed the selector in the middle we got air hissing sound. So it became apparent that the valve gasket is damaged. The model number for the  "Two Way Fuel Tap ( Twin Tanks ) 526783". The gasket number is NRC5364. We are in process of cleaning it up and dismantling it for rebuild.
We were able to run the engine by feeding fuel directly from an auxillary Jerry can. The engine was fine.
So now that we have identified the problem, will order the parts and repair.

Cheers