W124 300 diesel engine stop

[Druk]

The Haynes manual 3253 referring to the vacuum stop element on the injection pump says...

"When the ignition key is turned 'OFF' the switch interrupts the supply of vacuum to the shut-off module stopping the engine"

This surely is incorrect? Me sucking on the vacuum module causes the manual stop lever to move across presumably to the 'stop' position. Does the ignition switch -when its switched off- not put vacuum to the element causing the engine to stop?

I'm trying to arrange a remote (not vacuum) STOP mechanism and am confused. Engine not as yet in a running state to be able to try it out.

 

[carat 3.6]

Iirc turning off the key sends vacuum to the stop mechanism, so your correct.

How are things progressing on your project anyway, I havent seen an update lately?

 

[Druk]

Thanks. Just in the throes of various plumbing work. Power steering, fuel lines, heater pipes etc. And converting it to a cable throttle is proving interesting.

http://www.mercedes-benz-club.co.uk/members/forum/forum_posts.asp?TID=28524&PN=5



.

 

[carat 3.6]

Which diesel pump did you use Derek? Turbo, non turbo, or hybrid?



edit: Oops didnt spot the link!

 

[Druk]

Hybrid. 124 pump with the 6mm elements from a 210 and the output calibrated to a 300 turbo. Fingers crossed.

 

[Dieselman]

Have you fitted a charge pressure aneroid to accommodate turbo boost needing increased fuel.

 

[Druk]

Have you fitted a charge pressure aneroid to accommodate turbo boost needing increased fuel.

No I haven't. Can you explain please. I was under the impression from the pump people that it was set for turbo requirement as is.

 

[Dieselman]

What they have done is increased the maximum fuelling capability to (hopefully) match the full charge of air under load.
The boost aneroid reduces the maximum fuelling to accommodate lower/no boost pressures.


Without the aneroid you should expect smokey off boost performance when the accelerator is pressed down.

 

[Druk]

OK understood.

So where should an aneroid wotsit be fitted to and what controls it? I looked on the EPC at the workings for a W124 turboD and there seems nothing on thats pump that I've not got. Effectively, all I've got is a 210TD engine converted to the same spec as a W124TD. Both have the altitude Alda thingy on the top but both are 'unused' according to the EPC. What controls the fuelling on a (continental) 124 300TD with it's turbo?

 

[Dieselman]

Instead of a altitude aneroid you need an ALDA, which has a boost pipe port as well as a atmospheric one.

 

[carat 3.6]

Instead of a altitude aneroid you need an ALDA, which has a boost pipe port as well as a atmospheric one.

Will, if the boost port on the alda is not connected will the turbo pump behave like a non turbo pump, or are they preset from the factory to deliver more fuel?

 

[Dieselman]

The pump is normally set to give maximum delivery for the version required, so no boost means less fuel.

 

[carat 3.6]

Say I fitted a om603 turbo diesel pump onto the om606 non turbo engine in my s124, would it overfuel the engine or behave normaly?

I ask because I would like to upgrade the car with a turbo and intercooler ect, but as it is my daily driver I'd like to do it in steps at the weekends.

My thinking is that I could swap the pumps over in readyness for when I fit the turbo.

 

[Dieselman]

Good Q.

it should hold the fueling back to unboosted levels, I think.

 

[carat 3.6]

I supose the worst that could happen is that it chucks out some black smoke?

I'm thinking about getting the pump and intercooler fitted first, then fitting a turbo and connecting everything last. I thought doing it that way would be best, as the steering box vs turbo space issue may take some trial and error to sort out.

 

[Dieselman]

Make a new manifold to raise the turbo up then squash the exhaust pipe to clear the steering shaft.

 

[carat 3.6]

Sounds easy when you say it. I'll have to take a trip to the laser cutter's and get some exhaust flanges made up.

One more thing to pick your brains with, any idea what sort of boost pressure the om606 turbo wastegate opens at?

 

[Dieselman]

1 Bar as standard, but the OM 606 will take a lot more. Some of the Finnish Super-turbos are pushing 500Bhp with no engine mods at all.

 

[carat 3.6]

Yeah, I've often watched youtube video's of those cars, wondering what they must be like to drive. My goal in the short term would be to bring the power up to the same level as an e300 turbodiesel, 177hp I think.

I did hear the non turbo om606 has weaker engine internals that it's turbo brother, how true that is I dont know. But perhaps increase the boost presure till the diesel pump gets to limit of the standard settings and leave it at that?

Should liven the old thing up anyway.

 

[Dieselman]

The only thing I think might be different internally would be the under-piston cooling jets might be missing from an N-asp version.

I think 200 Bhp should be a starting point and go upwards from there.