12/1 Listeroid GM90 won't start - please help

[cornwallav8r]

I will check.  Interesting on the pump differences, I was under the assumption that the manufacturers obtained 12 hp from a 6hp by doubling the rpm (mine is 1050 rpm I believe) and changing the flywheels to smaller diameters to permit the higher speed.  That would mean twice the rpm, twice the number of injections, but the size of the injection wouldn't have to be different since there are double the quantity?  But I suspect you may be correct, I  will go check.

The old pump doesn't pump at all, yet I had it apart, and it doesn't appear the element is scored at all. I see a definite wear pattern but it isn't scratched.  I would think it would still pump reasonably well but past efforts have failed.

[cornwallav8r]

I am back from comparing new and old pumps. They are identical.
I did notice the plunger is really tight in the new pump.
Almost to the point it could possibly hang up despite spring pressure.

I looked at the old plunger parts, and there is some very light vertical surface scratching. Nothing deep, just enough that it takes some sunlight to be able to see it.
I know these are precision parts, I wonder if the old one should still work.    I guess I can find somewhere to buy a replacement plunger set.

[cornwallav8r]

For the record, since you didn't ask, I determined the 20 BTDC location by measuring the flywheel circumference, dividing by 360 degrees (0.1877 inch I think it resulted in) and multiplying by 20 to get somewhere around 3.75 inches advanced from TDC.

[Tom]

That method sounds right and just to confirm, when standing with the IP in front of you the mark on the right flywheel will be 3.75" farther from you than the DTC mark. I use the pivot bolt for the governor bell crank as my "pointer".

Perhaps the bottoming you thought was happening was the plunger to tight in the bore.

[cornwallav8r]

Right, I am using the shutoff control arm's pivot bolt, I scribed a line in it.  The 20 degree mark on the flywheel is to the right of the TDC mark.

And now that you mention it, maybe that is exactly what it is, just tight inside.  What is the recipe to fix that?  Attach a drill to the end and spin it a bit moving up and down the bore, to break it in a bit?    Don't know what else would work.  The Indians leave a lot to be desired in the QC department don't they?

[32 coupe]

All that timing jazz does no good if you  don't KNOW where true TDC is.
Don't trust the factory mark.

If the cam timing is correct, valves open and close with compression  and fuel it will run.
You stated the injector is good. I'm assuming you hooked it to the pump line
and "fired" it into the open air ? You can't miss a good one when you see it.

I have had pumps "bottom out". Usually it's because I didn't have the timing set
correctly.  One engine I have won't let me run the timing as advanced as "advertised"
because one of the pumps will bottom out
but running it slightly retarded it seems fine. It starts easily and produces full power.

With that said, over and out.
Gary

[cornwallav8r]

Ok partial success.  Got the spill timing as close as possible.  Tried again to no avail, then added about an ounce of oil into the intake, then got strong pulses, even ran for a short time till I shut it down to make adjustments (read: handle was still attached and looking for somebody or something to fly off and knock the hell out).  Wouldn't start again without half an ounce of oil or so each time, and then it pulsed nicely on each compression stroke but not enough to self sustain.  These are new rings.  Is this normal?

[cornwallav8r]

32 coupe, yes the injector air fires just fine, 3 nice misty pulses.
And yes, I found my own TDC, there is no factory mark.

It seems to now be a compression at the rings issue as they are new.
Scares me how much oil I had to pour into the intake to get the rings airtight enough to fire.
Lots of black smoke.  Even ran for awhile.
What's the recipe here, get it running and let it run an hour or two to get the rings broken in enough to seal?

[Tom]

I'd return the new IP for a replacement, then order a repair kit for the old one. That way you have a backup.

[cornwallav8r]

The pump now seems to be working perfectly. No binding. It sure was tight at first but now it's fine.
Compression seems to be the remaining issue.
How long should I have to start with a shot of oil to get it running?  Even now, it's hard to start that way as it is.

And by the way who besides the England based store, sells these parts?
I see an "Engineering" something or other named seller on ebay, I think that's the guy I bought this pump from.

[32 coupe]

Good deal, you got it fired up !

You shouldn't have to add oil to get it to start.

Have you played with this type engine before ?
They do require a certain knack.......after a few
dozen starts you'll get it. ha ha !  That first few seconds
after flipping the fuel rack open and throwing the
decompression lever while attempting to crank the thing
over will make your hair stand on end !

They like to run with a load on them. 

Gary

[cornwallav8r]

Still not there though. Won't start or even try unless I put a load of oil into the intake pipe.
Then is hits hard, and either aids rotation but not quite runs on its own, or randomly, does run with lots of black smoke.
Can't currently get it started again. But it's late and I am tired :-)
Had my engine expert over the other day, just got off the phone with him, he says my compression is terrific.  He thinks it's the injector.
But it's new, and I just did an air burst test, it pounds out a beautiful 2' long mist in 3 directions, with authority. I don't think it's the problem at all.  Though I haven't seen a video showing a proper lister injector firing, I can't imagine one firing any better than this one does.

What's next?  Thoughts as to why I have to start with a shot of oil?

I think I will go over my timing one more time, as I can't believe fuel quality, compression or injector are the issues.
Will try that spray onto the flywheel trick and double check timing.

[32 coupe]

" 2' long "  ...........all my injectors put out a super fine mist.......looks like a small cloud....
can you check the new pump with old injector ?

Just a thought....

Gary

[cornwallav8r]

Mine is a cloud, but sprays a 2' distance as a fine cloud.
I do have 2 more brand new injector bodies, I can try those as well.

[38ac]

As to why you have to add oil to make it fire.
The oil preforms 3 functions that aid starting
1. It seals leaking valves
2. It seals leaking rings
3. It takes up space in the combustion chamber thus raising the compression ratio and thus builds higher heat.

Assuming you have proper timing and fuel delivery your trouble shooting sequence should be to remove the muffler and intake flanges and crankcase door. Bring the engine up against compression and listen for leakage at the valves. Should be none to barely perceptible. Then do same while listening inside the crankcase door. Rings will always leak some, new rings a bit more how much is hard to describe. If you hear a rush of air that is a problem. If al that checks out you need to check bump. The bump for a D.I engine is not the same as an IDI, I am not familiar with the head design on a GM90 but the D.I Metros I have been around the bump is much larger than a regular CS type IDI head.