All things to check on Turbo OM617

[haromaster87]

Hey guys,

So I'm working on getting my car(1984 300D Turbo) tuned as well as it can be. I know this info has been posted in various threads, but I was thinking maybe we can gather everything into one thread. Most of the info I'll be referring to is for the OM617, but I believe a lot of it applies to other engines.

I'm mainly looking to gather info on the things to check/tune in terms of Fuel and air delivery on these engines. Not so much a checklist of everything to check on a newly acquired car, just fuel/air delivery.

I'm asking because I'm getting rebuilt injectors with new nozzles, and I plan to turn up the boost a bit on my turbo, and open my ALDA up a bit. However, I read about a lot of people who do these things to make up for performance lost in other aspects of the engine. This is where I think it would be good to have a good check list of things to look at, and how to check them.

First the things I know about:

1. Air Filter: Self explanatory, easy enough just to replace.

2. Fuel Filters: Clear and spin-on can type filter. Again, easy enough to replace. Don't forget to fill the can filter with Diesel.

3. Banjo Bolt: Back of the intake, gets gummed up, best to remove and clear out with brake cleaner

4. Diesel Purge: debatable how affective, either way it's cheap and doesn't hurt to try.

5. Valve Adjustment: Easy enough to do, requires a few special tools, almost always makes an improvement in performance.

These are are of the things I can think of. Minus tuning the Alda, Kicking up the Boost, and redoing the injector nozzles. I remember reading about a Vacuum Module that had to do with the turbo that should be checked, but I can't find that info again.

I'm pretty sure there are some other things to check for. If you know of anything, that's simple enough to check/service, and can help fuel/air delivery and contribute to the engines performance, post it up so we can add it to the list. Hopefully we can end up with a good one stop shop. If it gets good enough, we can link each step to a good how-to. But even if not, it'll let people know what to search for. If this has been done before and I missed it, please excuse me. haha

[toomany MBZ]

Depending on how many miles, maybe a new timing chain.

This is the step adjusting the ALDA corrects, perhaps. As it will get your timing back to factory specs.

Not sure how to turn up the boost, but you need more fuel as well for it to work. Vacuum modulator, for the engine fuel system? Haven't heard of that either.

There is a web site dedicated to super diesel type tuning, most here, myself included, prefer a stock set up.

You have good list going.

[haromaster87]

Originally Posted by toomany MBZ

Depending on how many miles, maybe a new timing chain.

This is the step adjusting the ALDA corrects, perhaps. As it will get your timing back to factory specs.

Not sure how to turn up the boost, but you need more fuel as well for it to work. Vacuum modulator, for the engine fuel system? Haven't heard of that either.

There is a web site dedicated to super diesel type tuning, most here, myself included, prefer a stock set up.

You have good list going.

Ah, that makes sense with the ALDA and the timing.

And the boost is different depending on if you have a Garrett or KKK turbo. They say only a few more pounds is usable with a stock/unaltered injection pump, but it does make a little bit of a difference.

I'll have to find the thread were I saw that in. I remember the guy was reporting a 30sec 0-60 time and if I remember correctly he had checked the banjo bolt and other stuff. Then someone mentioned this vacuum piece which he found to be clogged and once he replaced it was was back to a 16sec 0-60. When I say it like that, it sounds like the Banjo bolt but I remember he had already cleared that.

I've been on SuperTurboDiesel. Great site, but they usually start getting very extensive into there mods. I wanna keep the list down to simple stuff that just about anyone can do, just to ensure they're getting the most out of there stock set up. Really helps when pulling into busy traffic. haha!

[Diesel911]

If your Turbo has the Rubber Hose going from the Intake Manifold to the Waste Gate some people have installed a inexpensive manual boost controller valve as sold on eBay for around $10.
You adjust the spring loaded valve so that the valve will not open until the manifold pressure you want is reached.
When the Valve opens your Wastgate gets the Manifold Pressure.

[Codifex Maximus]

While yer doin' those fuel filters, you might think about replacing the primer pump. Especially if you see evidence of fuel leakage.
Check the throttle bushing on the firewall to make sure it's not degraded.
Check the air cleaner housing for play. May need new rubber air cleaner mounts (3) and/or new mounting bracket. U-pipe should be secure and not leaking air. Make sure oil drain in air cleaner is properly inserted in drain pipe.
Check for leaks on diesel overflow/recirculation hose. Hoses at fuel tank too.

Some of these are obvious - others not so.