OM617 won't start - Page 3 - PeachParts Mercedes-Benz Forum

leathermang · #31 09-19-2016, 11:33 AM

Quote:

Originally Posted by funola

WD-40 alone will not guaranty the engine will fire, BTDT. Engine needs enough compression and cranking RPM. I had an engine with good compression but a weak starter motor and I was unable to get it to fire by spraying in WD-40 due to very slow cranking (around 120 rpm).

True.... better to try ' starter spray ' in that case....

funola · #32 09-19-2016, 11:35 AM

Quote:

Originally Posted by leathermang

True.... better to try ' starter spray ' in that case....

I would not recommend starter spray. Better find and fix the underlying issues. Adjust the valves, check compression readings, find the leaks and get rid of the air.

getlost4x4 · #33 09-19-2016, 11:51 AM

Ok, update

I just primed it 100x's. The plunger got harder to push as I hit the 60 mark. I got all the air out. But it seems like it should be harder to push. From experience using a plunger on other types of cummins engines.

Battery was charged fully this time. And was spinning a bit faster. I don't know if I have a fuel problem. I can feel the block getting hot as I preheat it with the glowplugs.

I guess my next step is to try to get a new plunger. maybe its not working correclty.

I'll try popping the injector lines at the block as well tonight, when i have some free time.

getlost4x4 · #34 09-19-2016, 11:53 AM

By the way, the engine only has 145K miles. I saw the speedo before it was removed.

tyl604 · #35 09-19-2016, 12:56 PM

I have never noticed my plunger getting very hard when I was pumping it up after running out of fuel. Also never think it got so much pressure that the pressure relief valve popped. I just sort of pumped it up for a while and then started it. I think you are supposed to keep the pedal on the floor while you are cranking it in this scenario.

getlost4x4 · #36 09-19-2016, 01:26 PM

i'll try keeping the throttle open all the way as well

barry12345 · #37 09-19-2016, 02:48 PM

Quote:

Originally Posted by getlost4x4

Ok, update

I just primed it 100x's. The plunger got harder to push as I hit the 60 mark. I got all the air out. But it seems like it should be harder to push. From experience using a plunger on other types of cummins engines.

Battery was charged fully this time. And was spinning a bit faster. I don't know if I have a fuel problem. I can feel the block getting hot as I preheat it with the glowplugs.

I guess my next step is to try to get a new plunger. maybe its not working correclty.

I'll try popping the injector lines at the block as well tonight, when i have some free time.

As long as it got harder to press the relief valve was allowing some pressure to develop. You do not need the full pressure to just run.

Unless you have verified the lift pump is producing you could have someone pumping steadily with the primer pump while you try to start the car.

It is not wise to believe the odometer readings on these cars. You instead look for any form of collaboration you can find. For example at 140k I would expect the drivers seat to still be in good condition. Even as new is possible.

The original upholstery on these cars is very durable. Typically as the miles build up the bolster on the drivers seat wears to the point of being breeched.

I just love these ebay examples where the claim for milage is just 200k and the drivers seat shows substantial wear.

I am in eastern Canada where at one time we could find low milage examples of these cars that were totally rusted out for parts. They where only weak at best in dealing with the high amount of road salt used here.

funola · #38 09-19-2016, 03:00 PM

Have you tried cracking an injector line (at injector) 1/4 turn, glow for 15 sec, then crank till it starts? Once it starts, close the inj line nut. If it starts that way, there is air in the system.

leathermang · #39 09-19-2016, 03:36 PM

Quote:

Originally Posted by funola

I would not recommend starter spray. Better find and fix the underlying issues. Adjust the valves, check compression readings, find the leaks and get rid of the air.

I know....and you also do not think anyone should pull the precombustion chambers no matter how many miles are on an engine or how many other potential problems have been marked off the list...
But a spritz of starter fluid... if that makes it start... means it IS a fuel issue.. simple cheap and fast... that fuel IS an/the underlying issue if the engine it not getting it...

leathermang · #40 09-19-2016, 03:37 PM

Quote:

Originally Posted by funola

Have you tried cracking an injector line (at injector) 1/4 turn, glow for 15 sec, then crank till it starts? Once it starts, close the inj line nut. If it starts that way, there is air in the system.

Sixto and I mentioned that in posts 3 and 4.

NZScott · #41 09-19-2016, 10:46 PM

Cranking speed sounded fine to me, imo...750CCA is plenty...I was using a 480CCA for years

I'm sure this issue will be something pretty simple if it's been going not long before.

As an aside, I hope your M pump is adjusted to give more fuel for your turbo.

leathermang · #42 09-20-2016, 11:02 AM

Quote:

Originally Posted by NZScott

.....As an aside, I hope your M pump is adjusted to give more fuel for your turbo.

Also, might check to see if the ' rate curve' built inside the pump needs to be different for a turbo .... not sure the correct words..... perhaps determined by a curved item inside the IP... ??? The assumption would be that above 2000 rpm the rate of increase of needed fuel would be more than the relatively straight line of the non turbo as a function of rpm...

getlost4x4 · #43 09-20-2016, 11:18 AM

Ok, so an update.

Just cracked each injector line at the top of the injector. Each one was able to put some diesel out. Doesn't seem like a lot is coming out. But i'm not exactly sure if it should be shooting out or dribbling out. So there's that.

I tried spraying some WD40 up the turbo. Still not starting.

I guess, the next thing to do is check compression.

Then adjust the valves, check the timing out.

Anyone have a write up on checking the timing on everything?

Thanks

getlost4x4 · #44 09-20-2016, 11:18 AM

I also tried to pump the priming pump while starting, it didn't make a difference either.

leathermang · #45 09-20-2016, 11:24 AM

You said it ran before it was pulled..
only certain things get altered in the things you have done since it was running..
concentrate on returning those to normal...