Thanks for all the input everyone! A lot of valuable information is much appreciated.

Find your Doosan dealer and have them update the ECM to V12. Cuts down crank time significantly. Fuel system supplier fixed the problem.

Gump
It seems this thread has intermingled 2 issues. Your 2.4L issue is different from the issue with the 4.3L
If you want to call me I can help you with this. 970-481-8351. More than happy to help.
ForkliftFan

The unit is a L.P. Unit with a 2.4L engine. It starts somewhat quicker when warm but not like it should. Doosan says problem is normal....I told them they should try telling that to a customer who just spent $25K on one of their units! Engineers with Doosan state..."Normal crank time is 14 seconds" but this unit cranks for about 25 seconds when warm and a bit more, at times, when cold.

Gump;
What checks have been done at this time. I see G430E power package for this truck. Question is are we talking about a dual fuel Tier II, gasoline or LPG unit?

Thanks for the info. Unfortunately this has turned into a back burner affair as I just got an additional 24 pcs. of equipment dropped in my lap at our other warehouse on top of the 113 I already had here. As long as it's runnin'!

Joe D, Gump,
My guys say check for poor grounding of the distributor at or near the intake manifold.

Also, if you can use Motoview to monitor RPM during crank to make sure you are getting a clean signal from the crank sensor. If you're not getting a clean RPM signal, it may be disabling spark until it sees a clean signal. I.E. software will not enable spark until it sees a RPM above 100 RPM.

Hope this helps, Forklift Fan

I would go with the grounds. We have several Toyotas with the 4.3. When we get new trucks in we automatically clean all the grounds, and run an additional ground wire from the engine block to the battery. This has resolved the majority of our long start times.

Ah the wonderful Lp powered 4.3... Check your compression with three steps. Dry, wet and than leak down. If this engine was not built with the prestolite (think that is the right name) valve seats than I suspect that you have burnt valves and valve seats. Had a number of failures of valve seats due to higher heat of LP gas ignition. The trucks would be hard start, act like they needed tune-ups, spit burp and backfire.
Good luck and let us know how you make out

this is a normal issue with machines fitted with ECM,

WIth this problem , starter are also getting damaged if compared to earlier Doosan machines ,

We can remove spark plugs and then try to see if spark is coming while craking.

spark plugs also to be changed as per manual.

We had this problem with the vortecs in the Toyotas and to fix the problem we had to take all of the ground wires on the chassis off and grind the factory paint off down to bare metal. We found that the paint was insulating and we were not getting proper grounds just from the bolt threads themselves. You have to find all of the smaller grounds and not just the main negative. Hope this helps.

I can attach a spark checker and for the first 3-4 seconds there is no spark through the wires.
Joe,
I think this is the first think to figure out. "What's the system?" , as my mentor at Clark in the 80's would say. If you had a service manual and wiring schematic it would sure help.
If you are starting in 5 seconds then that means you are starting in 1-2 seconds after you get ignition fire.
Are you getting key switch voltage at the distributor immediately or does this take a few seconds also?

Does that truck have a diode in the ignition circuit. It would be in harness on right side of truck back next to radiator. It is a blocking diode between LP lockoff and ignition. Had one blown open once and caused hard starting. Picked up diode at Radio Shack, Truck started right away every time after that. Unrap harness and look for diode assy.

I would check into a service improvement from the factory on these things. Is the ignition looking for a set oil pressure reading before allowing spark? Just a guess, slow to build to working pressure, kinda like a safety prior to start? Remember the old Clarks had oil pressure switches that kinda did the same thing. Tokk a while to start, looking for oil in the pan.

We've had the "long crank" issue since day one. A year or so again we started having back fire issues through the intake filter assy. We found that due to the backfires it had blown the mixer diaphram apart. That was changed and the regulator was changed. Still backfires. The factory insisted it was an ignition problem so the entire ignition system was changed (coil, wires, plugs, cap and rotor) and still backfiring. We could minimize the backfiring by adjusting the timing but the n we had this up and down RPM whil sitting. Then we pulled the mixer off and cleaned the throttle body. Same problem continued with idle, backfiring and long cranks. So i pulled the intake and gave it a good flushing. Now the idle issues and backfiring are gone but the "long cranks" are still there so even after putting on a new regulator the problem was still there.

I can attach a spark checker and for the first 3-4 seconds there is no spark through the wires.