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

[cornwallav8r]

I am reconditioning a 10 year old GM90 listeroid.
The work I did included:
Installed new rings after crosshatching the cylinder
Installed new head gasket
Lapped both valves
Installed new fuel pump and injector

I checked the cam timing, it is still exactly correct.
I adjusted the spill injector timing, though note I found 3 different methods. Those that required removal of the pump inner check valve and spring, and turning the flywheel before and after the 20 BTDC inject location, don't make sense.  They indicate to turn the flywheel backwards till the flow starts, then forward till it stops.  When in my case, the opposite happens, in reverse it stops, and starts when rotating forward to the 20 BTDC mark.  Seems to me those instructions are written backwards?
I used the other method, leaving the pump internals installed, watching for begin of flow at the top of the pump delivery hole, matching it to the 20 degree position.  Makes sense right?

At any rate, I only ever get a puff of white or gray smoke and a  bump.  The fuel was properly bled, I get the proper injector squeak, and the engine has super (seems to me) compression, it's almost impossible to turn without the decompression lever in place.  The ignition bump does not aid the engine in starting, it's jsut a resistance bump each time.

Any thoughts what this might be?

[mike90045]

........At any rate, I only ever get a puff of white or gray smoke and a  bump.  The fuel was properly bled, I get the proper injector squeak, and the engine has super (seems to me) compression, it's almost impossible to turn without the decompression lever in place. .....

Almost impossible to turn w/o decompression...  In my case, I cannot turn without lifting the decompress.   You may have ring leakage, try a shot of oil into the cylinder to aid sealing the rings, it improves compression a bit, if leakage is the problem
  I assume it was running and starting before the repairs ?

[M61hops]

Hi cornwallav8r.  Your engine needs 3 things to run: compression, fuel and timing.  Which insn't happening?  I'd take the injector off the head and spray it into a jar while cranking the engine over to check the atomazation, spray pattern and flow.  If you have all 3 requirements adequately    met it will run.   

[cornwallav8r]

Yeah, I pretty much can't turn it either, without decompressing so I doubt that's the issue.  The rings are new, but not broken in yet in a cross hatched cylinder.
There's plenty of fuel getting in there to seal the rings :-(
The injector is new, it clanks and atomizes. Not sure how to compare it to other injectors, but it sprays 3 fine jets like it probably should.
Have been trying many time to get it to start, so I wonder if there's too much fuel in the DI piston's bowl?

Timing is likely the issue if it isn't just flooded.  Anybody got a good lowdown on an injection timing procedure that makes sense?
I noticed when you get the pump to start pumping at 20 BTDC, the actual clank follows much later after TDC when turned by hand.
Is that correct, at least for slow turning?  Something about this timing doesn't make sense, it's likely the issue.

And yes, it used to run fine, was just replacing some parts to refresh the engine.  The new injector pump appears to have changed the timing which is why I started changing that.

[cornwallav8r]

I think something that would help, is if somebody could confirm approximately when the clank happens, as a second check, when turned by hand...

[38ac]

You cannot "flood" a diesel, that is not your problem. Excess fuel laying in the piston bowl, up to a point will aid starting as it takes up space and adds compression. It will exit as smoke and splatter, very little will burn.
 I would start by confirming timing. The easy way to do this is to find TDC and plainly mark one of the flywheel rims at the top.  Or if you have a pointer mark it there. Use tape or contrasting paint marker that is easy to see. Then  turn the engine while watching the valve lifters and when you come to the point where the exhaust valve is coming  closed and the intake valve is opining up stop at the point where both lifters are more or less equally raised. You should then be very near your TDC mark, or slightly before it, never after. Double check several times prior to making decisions. Next is to confirm the injector timing by ear. Decompress the engine and turn a few revolutions until the inject is creaking steadily. Slow down the cranking until it is just audible and watch the timing mark as you crank. Another rmethod is to feel the injector as you crank. The best method if you have a spare line is to remove the injector and bend the line so it holds the injector above the face of the fly wheel. Then turn the engine and spray some fuel on the flywheel. Where the spray pattern starts you should be at your sill timing degrees.

After all this if your engine will not start you have compression issues. Culd be rings, valves or just dry. If dry some oil in the intake will fix it. Remove the air cleaner and with a pump can reach back and give the intake valve 6-7 squirts and try to start the engine. You can try some starting fluid and wont damage anything if you do it right.  Hold the can 3-4 feet away from the intake, carefully aim and give it only what you can spray as fast as you can push and release the valve.

[cornwallav8r]

Thanks for the clarifications.  To be more specific, you say to rotate while listening for the injector to creak....am I looking for close to TDC at that point?  You didn't specify (or it isn't clear to me), and I am not sure what the timing difference between spill 20 deg BTDC timing, and the actual injector burst.  I read somewhere a guy with a timing light found 2.5 BTDC for actual injection.

I think I am onto another underlying cause.  The pump I was supplied was sold as compatible with the GM90 CS style engines.  It certainly looks and fits the same.  Its only difference visually, is the rack has a pin connection at both ends, instead of being cut off at the unused, right end of the rack.  From memory, I think the last part of the model number is 80 CS 170 or something like that.  When my cell phone recharges I will take a pic.

But what's REALLY PUZZLING is that when I screw the injector plunger adjustment upwards to move the spill timing mark closer to 20 degrees, I bottom out the pump internals.  Either there are multiple places (I don't fully understand the pump workings) I can achieve the 20 deg spill timing (meaning I am doing something radically wrong), or this pump is somewhat incompatible.  It works fine otherwise.  Seems to me a couple wide fender washers under the bolted base would move the pump in the right direction, upwards, to achieve full pump travel and proper timing.  Currently, set anywhere near 20 BTDC spill timing, the plunger remains always, anytime over a full revolution, partially compressed (no clearance) into the pump cavity.  Of course it plunges upwards but never backs off and leave some clearance between plunger and pump internals.

Thoughts?
 

[George A]

A suggestion..........and that's ALL it is..........put a FEW drops of gasoline on a rag and hold it over the intake then try to start it. If it fires, it almost has to be a fuel delivery problem of some sort.

Note: the engine will have no governing if you use this technique, so use very little gasoline and be prepared for the engine to really speed up at first.

[cornwallav8r]

I can add a photo of the injector, but unsure of how to do it. I see the icon above for photo that adds quotes inline here, but what else must you do, cut and paste the  photo somehow?
The injector part number is (manufacturer: HIT of India) PF 1B 80 CS 175

[cornwallav8r]

George, for fun I might try that.  But at this point I pretty much am sure the timing is at a minimum, off, see the above message.
I will try shimming the pump upwards to get the stroke met without bottoming out at 20 BTDC.
Thanks, all of you.

[38ac]

Sorry I wasn't clear at all there. Technically speaking the injector should begin to creak at the spill timing point however that is very hard to discern. Thus the turn and listen test  is not an exact test but tells you if you are close. My personal Eye/ear/brain coordination causes me to hear/see proper timing about right at TDC. If you bend the line so you spray the flywheel the beginning of the spray pattern should be at the same point that you spill time. If you go to the WOK section and look though my build ther eis a picture of the injector spray test and better description.

[38ac]

ALso If you cannot properly spill time without bottoming out the pump travel that tells me your camshaft is miss timed being retarded in relation to the crankshaft.

[Tom]

If your bottoming the IP to get things in time, what's most likely happening is your cam is a tooth off. A couple of questions if I may. Do you have TDC marked on the flywheel? If so how did you determine TDC?

Assuming TDC is correct, your intake and exhaust valves should be at the center of their overlap on TDC if the cam is installed correctly. Is this the case?

[cornwallav8r]

Wow, again thanks for the thoughtful responses.  I determined TDC by placing a long screwdriver into the injector hole, and topping it off.  I double checked it just now by looking at the valves, and the exact middle of open/close relationship where the intake/exhaust valves are opening/closing places the flywheel's position about 3/8" to the right of my flywheel's TDC mark.  Should be about right?

I checked the camshaft timing per suggestion I read somewhere, as I recall intake valve should open about 5 deg before TDC?  Or after? Don't recall, but I thought it made sense at the time and moved on.

What should I check?  My comments about shimming make no sense of course now that I think about it, shimming achieves nothing that shortening the plunger bolt wouldn't achieve.
But the problem remains, I am bottoming out the pump, so maybe indeed the timing is off.  But this thing ran before

[Tom]

That sounds close enough seeing how TDC was determined. A tooth off on the cam will have a LOT of difference. So if you still have your old IP, is the stroke the same length as the new one? A 12 hp engine is going to need about 2x the fuel as a 6hp one, so if your IP is for a 6/8 hp GM 90 it may well not have enough stroke for your engine.

The extra hole on the rack is a clue that the IP you're trying to use would be for a 6/8 hp engine. The factory had a paul that you'd flip up for extra fuel for starting.