617 weird behavior diagnoses - Page 6 - PeachParts Mercedes-Benz Forum

Lucas · #76 11-28-2014, 02:04 PM

Your fuel setup reminds of the Johny Cash song. It's a 51, 56, 63 automobile. Obviously it's necessary in a swap.

Those PCV lines are high end. It's they run in a lot of race setups. I think it's one of those items they tax for that reason, for the guy building his civic for top fuel.

OM617YOTA · #77 11-29-2014, 02:27 PM

Yanked the gutted vacuum pump and ran the engine with the exposed timing device flinging oil about. No difference in the noise, and no evidence of anything smashing around inside the pump body. Stopped the motor, gave the timing device a yank and a shove.

At least 1mm of play. Much swearing ensued. Double checked the timing device mounting bolt, good and tight.

Extremely discouraged at this point. Anyone have a good 617.95x motor sitting around they'd part with?

OM617YOTA · #78 11-29-2014, 02:30 PM

Here's a possible donor car:

Om617 turbo diesel Mercedes 300TD

And just a motor, that seems to be in pretty tight shape:

Mercedes OM617 Turbo-Diesel Motor, Low Miles, Great Compression

Stretch · #79 11-29-2014, 02:40 PM

Quote:

Originally Posted by OM617YOTA

Yanked the gutted vacuum pump and ran the engine with the exposed timing device flinging oil about. No difference in the noise, and no evidence of anything smashing around inside the pump body. Stopped the motor, gave the timing device a yank and a shove.

At least 1mm of play. Much swearing ensued. Double checked the timing device mounting bolt, good and tight.

Extremely discouraged at this point. Anyone have a good 617.95x motor sitting around they'd part with?

Don't chuck teddy out the cot just yet.

I know it is a pain in the arse but take it to bits and investigate first.

Lucas · #80 11-29-2014, 02:43 PM

See if my 615.912 device will fit via the EPC. I'll hook you up. I've already more than returned my investment on my $500 junkyard motor.

1970 220D. 115.110 chassis American.

And hey you found the culprit without your mb guy. And it was not any of our guesses.

OM617YOTA · #81 11-29-2014, 03:52 PM

Thank you for the offer, that's incredibly generous.

I'll poke about and see if it IS the timing device. Right now I'm thinking it's something to do with the intermediate shaft. Tearing into it that far will have to wait, right now I need my truck able to move under it's own power.

Discouraged but still moving forward, such is life. Still beats a truck payment.

Minder · #82 11-29-2014, 04:14 PM

Hi, just a thought, some engine will partially run on their own oil via the piston rings and valve stems causing knocking and pinging like when a diesel starts from cold. My guess is your timing isn't right. I have just for observation altered the times but about 10 degrees just to see what the outcome is. If you have white smoke the pump is retarded, to much knocking and it's to advanced. If you remove the number one injector pipe and use the outlet of the pump on number one to indicate start of injection you may get a better setting. Clean out the hole with soft cotton rag and you can see when the start of injection is and so align the pump with the correct marks. Much better than the drip idea. Peter

leathermang · #83 11-29-2014, 04:29 PM

Quote:

Originally Posted by Minder

.... Much better than the drip idea.....

THE DRIP IDEA ?????????????????

The specified method from the Factory Shop Manual published by the people who have been making automobiles for one hundred years.....with millions of dollars of research and development money to spend on the engines THEY BUILD .....

it is ' AN IDEA ' ?????????????????

Lucas · #84 11-29-2014, 07:15 PM

Lol. I was reading the previous post and was thinking "oh he's gonna say something."

To be honest I struggled with drip timing at first. I think I expected it to be more scientific or dramatic. After seeing the FSM I'm gonna turn an old pre filter into a sight glass.
The other FSM method was cool. If you have an extra fuel pump. Seems like it would give more dramatic reactions. Not that it's needed.

I didn't quite understand Minder's method. On a 4bd2t you watch the fuel rise up out of the delivery valve with no pipe. Kinda reminded me of that.

leathermang · #85 11-29-2014, 09:33 PM

Quote:

Originally Posted by Lucas

..... I expected it to be more scientific or dramatic....

Well, no, unless you set fire to the fuel it is not dramatic...

but the SIZE of liquid droplets .... since we are all using the same fuel... at about the same temperature.... is pretty standardized.... read ' scientific '...
There is some unresolved standardization of the pressure behind the fuel flow... and I wish that could be fixed... but I am sure MB took that into account and the one drop per second gets close enough.

OM617YOTA · #86 11-30-2014, 09:56 PM

Well........

I replaced every millimeter of fuel line between the fuel tank and the lift pump with Gates Barricade hose, including a piece I had previously installed to run from the Toyota factory fuel line on the passenger side over to the lift pump on the driver's side. I had used this chunk for the bottle-under-hood test run as well as normal use, and I think it was faulty. So far the pinging and cold start roughness is gone.

Just the intermediate shaft noise now.

Stretch · #87 12-01-2014, 05:09 AM

There we go - good news!

OM617YOTA · #88 12-02-2014, 10:14 AM

Well, something made a difference right then and there for that one test drive. These last two mornings cold starting have been exactly the same as before, rattling like crazy. Wondering if me priming the air out of the new line made more of a difference. Next cold start I'll try priming it a lot with the hand primer, and I think I need to go with clear fuel line as originally planned.

Does the load that the injection pump places on the timing chain change with throttle setting?

leathermang · #89 12-02-2014, 10:39 AM

Quote:

Originally Posted by OM617YOTA

.....Does the load that the injection pump places on the timing chain change with throttle setting?

Yes, but NOT nearly as much as the camshaft does.....
it is doing more work... pumping... per unit of time..so more load...... but that double roller chain you have is amazingly strong...

mach4 · #90 12-02-2014, 11:04 AM

Quote:

Originally Posted by OM617YOTA

Well, something made a difference right then and there for that one test drive. These last two mornings cold starting have been exactly the same as before, rattling like crazy. Wondering if me priming the air out of the new line made more of a difference. Next cold start I'll try priming it a lot with the hand primer, and I think I need to go with clear fuel line as originally planned.

if you think air is still somehow part of the problem, you might want to consider adding a little 4psi "boost" pump to the system close to the tank. This isn't enough pressure to affect the lift pump but would keep the line with a slight positive pressure to keep from sucking air into the system. Would also be helpful for priming.

I'm thinking something like -

New 12V Universal Low Pressure Gas Diesel Electric Fuel Pump 1 4 Tubing 3 5 PSI | eBay

If you wired it with a toggle switch in the dash it would function as a true boost pump and you could use it for troubleshooting too. As an ex-aviator we always had boost pumps available - used for starting, landing and emergencies.