ALDA removal........OM603 - Page 30 - PeachParts Mercedes-Benz Forum

Jeremy5848 · #**436** 11-29-2007, 07:10 PM

Clearly, I need to decide what to do with this thing. I'd prefer to find someone who has had more diesel experience and could pull the IP without a thought (and sell them the car), let them put in a used IP. I've never seen (other than in pictures) an IP off of an engine, have never watched/helped anyone else pull one, and would rather not "learn by doing." Someone who was more of a mechanic than me could end up with a nice car.

Jeremy

gsxr · #**437** 11-29-2007, 07:19 PM

Yeah, I know what you mean. Unfortunately, it will be hard to sell the car for a good price, with it not running well. Even someone with the know-how is going to be nervous about paying good $$$ for a car with an unresolved problem like that. Now, if it's fire-sale priced... I know a couple of people in the Bay area that might jump on it. But I suspect you're not desparate to unload it. ;-)

Anyway, pulling the IP is not terribly hard - but the first time can be somewhat tedious. Figure 4-8 hours for a newbie. I'm sure if you start a new post asking for tips & tricks on OM603 IP R&R, you'll learn enough to be willing to tackle it. The only special tool you'll need is the IP lock tool (about $20-$25 from the dealer), and maybe the stubby 8mm socket ($5) to remove the fan/clutch. For parts, just a vac pump gasket, and a new O-ring for the block/IP junction, probably $15 total. Although if the pump comes off, I would re-seal whatever pump is re-installed (figure an extra $30 or so in IP gaskets). Removing the intake manifold makes things a LOT easier, but it can be done with the intake in place...

Jeremy5848 · #**438** 12-03-2007, 08:17 PM

All of us who fix up old cars know that it's hard to sell a car after doing a bunch of work without losing too much money. People who get lucky and find something that needs a few minor fixes but buy the car cheap because the PO thought it was a basket case are probably a very small minority. The rest of us end up spending more that we'll ever sell the car for but we aren't concerned because we plan to keep the car for awhile.

Such a thought has occurred to me regarding this 603-engined 300D. By the time I get the IP working correctly, the valve guide seal leak stopped, the sunroof working, and the ABS fixed, I'll have way too much invested. As GSXR has just said, selling the car as-is with those problems will be difficult unless I give it away.

An option, then, is to fix the problems and keep the car, selling the W123 car instead. The latter car is in great shape and I could come a lot closer to getting my money out of it. I'd miss the old thing but it would be nice to have a 124 with the smoother, quieter, more powerful engine.

While I think about it, I'm going to look for a wrecked 124 diesel or a good 603 engine. If I could find one with a late-model head (mine is a #14), I might be able to bypass the existing problems at a reasonable price and end up with a much better car. There's always the risk of bad parts in the used engine, of course, but it's something to think about.

Jeremy

sixto · #**439** 12-03-2007, 08:37 PM

Playing the devil's advocate - to me it would depend on the price difference between a good running 87 300D and whatever you can get for yours. In the extreme, you might be able to buy an 87 300D in good enough shape for what you expect to spend getting your car up to snuff.

Sixto
87 300D

gsxr · #**440** 12-03-2007, 11:46 PM

It's a tough call either way. I've owner several 123's as well as several 124's, and unless the 124 is a basket case, I'd have a "for sale" sign on that 123 quicker than you can finish reading this sentence. Once you get the 124 running properly, you'll never want to drive (or work on) a 123 again. But, it can take some real effort to reach that point. You could always market both, at the prices you want to get, and see which sells first...

Jeremy5848 · #**441** 12-04-2007, 12:41 PM

Quote:

Originally Posted by sixto

... you might be able to buy an 87 300D in good enough shape for what you expect to spend getting your car up to snuff...

Yes, that is very much on my mind. Thanks for reinforcing that point (and might you know one for sale?).

Jeremy

dieseldiehard · #**442** 12-04-2007, 12:58 PM

Quote:

Originally Posted by Jeremy5848

Yes, that is very much on my mind. Thanks for reinforcing that point (and might you know one for sale?).

Jeremy

I'd fix up the '87. They are so superior to the 123 that its worth putting time and money into one if it a good car to begin with (yes a MB can be a money pit but hey these are excellent vehicles, remember the '87 300D sold for something like $38K).

I just looked at CL and there's one in Redwood City for $3750 http://sfbay.craigslist.org/pen/car/492769580.html
but the one in the East Bay for $4200 really caught my eye, heck I might just not sleep well tonight wishing I had in my stall

"Dark red (rare color!)
The engine and turbo work great
The Transmission works great
-280k on the car it has been well cared for and will go to 400k easy
-Freshly rebuilt head ensures another 200K"
http://sfbay.craigslist.org/sby/car/494376540.html

I wonder if its a late # head? For that price I'd want to see it up close and drive it.

Now, if you need a reference to a good shop on the Peninsula I have a couple of places. PM me.
I'm not employed in the car repair biz any longer but if I was I'd help you out with some donated labor.

dieseldiehard · #**443** 12-04-2007, 01:08 PM

Quote:

Originally Posted by Jeremy5848

Gus says that he rebuilds all pumps that he gets ($1200), does not "calibrate" them. He said that I might be able to shop around and find a diesel shop that would be willing to bench-test and adjust the pump. Gus is of the opinion that , because of things that wear out, it is not possible to successfully adjust an old pump that is no longer working properly.

Installing a used but "known good" (we hope) pump looks like a better option.

Jeremy

I know Gus, a great asset in the Bay Area. He rebuilt an IP for me and provided a print out of the "calibration" if you want to call it that, its really the metered flow at various "throttle" positions (I can't help but use the term throttle when it really doesn't apply to a diesel) In the old days they measured the fuel in small test tubes as the IP was set up on what looks like an engine lathe to see the variation from port to port. I don't know what he uises now but its electronic.

Anyhow there was a used IP off a 603 on eBay last week for $475 seller claimed it was off a good running engine. That would have been a great opportunity for you. I'd be calling the wrecking yards if I were you, have you tried Acme up in Santa Rosa?

sixto · #**444** 12-04-2007, 01:28 PM

Gus showed me my SDL IP on his bench before I picked it up. It's a modern version of what dieseldiehard described. Each injector line sprays into a flow meter and it's all shown in a digital display. I don't recall if there was a pressure line into the ALDA for dynamic testing. The IP was returned to me with the ALDA adjustment screw capped with Gus advising me that, "there's really no need to touch that."

Next time (?) I'll ask if it's possible to test the IP with the timer to ensure it's advancing as it should.

Sixto
87 300D

Jeremy5848 · #**445** 12-06-2007, 08:57 PM

...mostly to give me an opportunity to look at the "dark side" of the IP (the parts that are hard to see 'cause they're under the manifold).

The first picture shows part of the linkage. It's attached to the IP and has three ball-and-socket connections. One comes from the accelerator cable, one comes from the cruise control, and one (with the arrow) isn't connected to anything. I can't see any linkage that is missing. Is this just a multi-use part that might be used in some other engine or configuration or is my engine really short a part?

The second picture shows the ALDA next to the shut-off valve and a third item with an electrical connector. Anyone know what this third thing is? Just curious.

The intake manifold is dirty but certainly not clogged up. The crossover pipe is quite clean, since I cleaned it and removed the EGR. I'll clean the manifold before putting it back on.

Jeremy

gsxr · #**446** 12-07-2007, 11:27 AM

The extra ball on the throttle linkage is not used. My pump doesn't even have a ball in that location (see my photo below).

The electrical connector is the rack position sensor. It's only used for the engine computer to control the EGR and ARV... in other words, it's kinda useless on the 1987 model, once you've disabled those items (which should be disabled, btw, if you haven't yet done so.)

Jeremy5848 · #**447** 12-07-2007, 09:10 PM

Thanks for the info! Yes, ARV is disabled, EGR removed, vacuum relays in a box, lines capped, etc. Used one of Brian's kits, worked great.

Intake manifold clean and ready to go back on, probably tonight or tomorrow.

Jeremy

Jeremy5848 · #**448** 01-30-2008, 07:33 PM

Update....

Manifold back on, engine running, etc.

I have purchased a used but recently (according to the seller) overhauled IP. I plan on doing Dave M.'s "OM603 Turbo IP Full-Load Adjustment Procedure" as posted in another Mercedes diesel forum before trying to swap the IP.

In another thread I have posted the results of the compression and leakdown tests done by a local mechanic who has previously worked on other parts of this car. I repeat these results here:

#1 compression 400, leakdown 0
#2 compression 300, leakdown 20%
#3 compression 460, leakdown 0
#4 compression 410, leakdown 0
#5 compression 420, leakdown 0
#6 compression 380, leakdown 0

The question for this thread is, how much of my lack-of-acceleration problem is due to operating on 5-1/2 cylinders? Maybe my IP is not that bad.

Jeremy

gsxr · #**449** 01-30-2008, 07:38 PM

Quote:

Originally Posted by Jeremy5848

The question for this thread is, how much of my lack-of-acceleration problem is due to operating on 5-1/2 cylinders? Maybe my IP is not that bad.

That's a darn good question. Honestly, I don't think it will kill power that much. Low compression on diesels can make them a bear to start, but once they're running, they can produce near-stock HP levels. My 602 just blew the head gasket, and despite ~330psi on cyl #1, the power level was pretty normal (just ignore the blue smoke trailing out the back). But it will be hard to tell for sure until you pull that piston and replace the rings (and possibly the piston as well). Talk about a rare failure... I've almost never heard of a 603 with a bad cylinder bottom end.

habraken · #**450** 01-30-2008, 07:43 PM

what works even better I found, is to install a pump off a 350.
and then 'adjust' the alda some

my wagon smokes the asphalt at 1/4 pedal

plenty of 350 ip's around anyway.

Quote:

Originally Posted by Brian Carlton

Thanks to the groundwork laid down by Forced Induction, I decided to remove the ALDA from the '86 SDL. It's always been a dog off idle and it was time for some adjustments. Turns out that the ALDA is virgin. Never been tampered with.

So, with Lance's info, I plugged the pressure line from the overboost solenoid and took it for a spin.

Lo and behold, the vehicle is transformed. Just 1/4 pedal will move it out relatively smartly and 1/2 pedal will outperform the city traffic.

But, the most important issue is the smoke.

There was no smoke at any operating point provided the rack was not more than 2/3 open.

I was able to get a bit of smoke if I mashed the pedal below 2500 rpm. But, if you drive the vehicle with any sense of reserve, you'll never get it to smoke.

Now, the best part of the story:

Two 0-60 runs on the same roadway........in opposite directions.......using the G-Tech Pro:

9.79 seconds

10.32 seconds

This vehicle is faster than hell without that ALDA installed.

So, all you 603 fans, my strong advice is to simply get rid of the ALDA and all the associated plumbing. You clearly don't need it.

And, my thanks to Lance for the groundwork that generated this thread. The general consensus for the need of an ALDA to control excess fuel is clearly far too conservative.