Help Tuning a 603 IP - Page 4 - PeachParts Mercedes-Benz Forum

Maxbumpo · #46 07-31-2017, 11:12 AM

Attached is a picture with labels for all the governor parts.

2m is the adjustment for maximum RPM. Each 1/2 turn corresponds to 150 RPM. Tighten (CW) to increase, loosen (CCW) to decrease. After much reading, I think this can be adjusted with no need to adjust anything else on the governor. Getting the shift points correct will then be a matter of bowden cable and vacuum adjustments.

2f is the full load adjusting screw. Again, tightening (CW) will increase fuel, so in your case I would try CCW to decrease fueling. BEFORE you try that, I would try adjusting the ALDA again, tightening (CW) in 1/2 turn increments until you notice a drop-off in off-line performance.

What I've read by Dave M. and others is that when 2f is tightened to increase fuel, it can affect the idle speed, so they recommend also adjusting the 2b screw (idle quantity) in the same direction and number of turns as 2f. You may find that you'll also need to adjust 2b if you adjust 2f.

Maxbumpo · #47 07-31-2017, 11:15 AM

I believe that the 3.5 liter pumps were set with a 4600 RPM maximum speed, while the 3.0 pumps were set to 5150. I'd recommend 1.75 turns CW to start if you want to be conservative, maybe go 2.0 turns if you want to see if you can get there all at once.

Diseasel300 · #48 08-01-2017, 07:45 PM

I have some baseline values, a gameplan, and an annotated photo of the governor assembly off the original IP.

For a benchmark reference, the 0-60 time with the IP set as-is with the WOT shift happening ~4200 RPM is right at 14s. I did the same run 4x and I varied from 14-15 seconds consistently. With the A/C switched on, I was more like 15-16s, so about 1s longer.

Currently, governed max RPM is just shy of 4500 RPM. Car in Park and foot to the floor WOT is about 1/2 needle width less than 4500 RPM.

After reading a lot a out the governors in these pumps, the fuel will start getting cut (and power reduced) several hundred RPM before the actual governed fuel cut. There's a noticeable drop in power above 4k RPM in this car which fits that description.

My goal is to restore the correct operating speed and back the fuel down to the point that the ALDA can do its thing and I'm not smoking people out. In the picture attached to this thread I have labelled the various adjustment points according to Bosch and Mercedes terminology.

I intend to turn the large adjustment labelled 2m 2 full turns CW, which should raise the governed RPM from 4500 to 5100 RPM in theory. At the same time, I'll turn the adjustment marked 2f CCW 1/2 turn and see if I still lay down a smoke screen.

If I'm right, the power should go up in the normal operating range and the smoke in off-boost mode should be reduced or eliminated. Additionally, the on-boost performance should be lacking until the ALDA is turned up. We'll see how it goes when I get a chance to work on the car. It may be a couple of weeks before I have a chance to really do anything.

bigpanda16 · #49 08-24-2017, 07:36 PM

I just want to throw this out there, but from my pump tuning experience...
On an M-pump, which is what this thread is based upon, 2f or the full load screw is turned out or ccw to Increase fueling or rack travel.
This is opposed to the rw governor in an MW pump which wants to be turned in or cw for more fuel/rack travel/full load/whathaveyou

Diseasel300 · #50 08-24-2017, 09:39 PM

So is 2F CW or CCW to decrease fuel? I guess it doesn't make a huge difference, it should show up on test. I'm planning to play with the IP tuning on Saturday and will follow up with what I did and how well it works out.

Maxbumpo · #51 08-25-2017, 03:11 PM

Quote:

Originally Posted by bigpanda16

I just want to throw this out there, but from my pump tuning experience...
On an M-pump, which is what this thread is based upon, 2f or the full load screw is turned out or ccw to Increase fueling or rack travel.
This is opposed to the rw governor in an MW pump which wants to be turned in or cw for more fuel/rack travel/full load/whathaveyou

Good catch, I got that backward.

Diseasel300 · #52 09-01-2017, 11:21 PM

I haven't forgotten about this thread. I was intending to do some tuning last weekend, but life got in the way. I am planning to spend some quality time with the IP tomorrow though.

This evening I replaced the valve guide seals in a successful attempt to stop oil smoke and oil consumption. Now that the oil smoke haze is gone it is very, very obvious that the IP is running extremely rich. Idling has a steady stream of black smoke and revving the engine produces a large noxious cloud. The same behavior happens even if the ALDA is disabled, so the ALDA is doing very little right now which makes sense since I have the screw nearly fully turned in.

Hopefully with some tweaking and a freshly sealed ALDA I can get some normal behavior out of this IP.

It is definitely nice to have the oil smoke gone, the smell it makes is unforgettable!

Diseasel300 · #53 09-02-2017, 07:54 PM

Finally did the IP adjustments today. I turned 2m 2.5 turns CW and got a rev limit of 5100 RPM which I'm happy with. I wound up turning 2f 1.5 turns CW to get the black smoke to stop. I still don't know why it was tuned so rich.

In addition to adjusting fuel and RPM limit, I re-sealed the factory adjusted ALDA with new O-rings and installed it on the IP.

The result of the adjustments and ALDA sealing is that my 0-60 time is the same as it was (~13.5-14s), but the smoking is stopped entirely. With the functional ALDA, the car is so much nicer to drive, power builds smoothly with RPM instead of being a slug to 2000 RPM then giving a very rough power boost as the turbo kicks in.

It'll be interesting to see how the fuel economy numbers turn out. Once people stop being idiots and hoarding fuel I'll fill up and get those figures.

Diseasel300 · #54 09-04-2017, 06:13 PM

I finally got the bowden cable adjusted where I'm happy with it. It seems that the sweet spot is to have it shift at 4300 RPM at WOT. I had it adjusted ~4500 RPM and it was hanging in gears longer than I liked at moderate throttle. With the readjustment it seems that I've taken about a second off the 0-60 time. I'm doing ~12.5s with no A/C or ~13s with the A/C on. Now that the engine can rev high enough, the kickdown switch actually does something useful and the transmission will no longer hang in gear with it pressed. ~4600RPM it'll automatically shift up even if the button is still pressed. Very happy with the way it's running and driving now.

I did manage to find fuel today, so I'll run some economy data over the next fill cycle. With the hot weather we've been having and the A/C running, I've been averaging right at 20mpg in town.

Maxbumpo · #55 09-05-2017, 11:05 AM

This is a great thread, thanks so much for posting your results so far. I'll be curious to see the new fuel consumption numbers.

I had never heard of rebuilding the ALDA (or at least I don't remember) so that is a new one for me.

Diseasel300 · #56 09-05-2017, 11:23 AM

I never like to start a thread and leave it hanging. I always try to follow up and close it out, assuming I ever get the problem resolved. In this case, there seems to be very positive results from what I've done so far, the biggest of which is the lack of overheating on the highway. At 75mph with the A/C running, the coolant temperature routinely hovered around 100-105˚C. No telling what the EGT's were doing to my turbo or head... Post tuning, I haven't seen anything over 100˚ while climbing a long, steep hill and temperature dropped back to 85˚ in under a minute. Highway temps seem to be in the 80-85˚ range now, definitely a significant improvement and very telling about how overfuelled the engine was before.

I drove the car last night around 10 PM so it was very dark. Had a modern Lexus behind me with the HID headlights so I took advantage of the opportunity to check for smoke. Only smoke I got was with foot hard down right at the upshift I got a little "poot" and that was it. Very satisfying not to have my own chemical fog following me around anymore.

The ALDA resealing idea came from this thread: OM602 ALDA o ring size If you get on Youtube and search for the ALDA O-ring, you'll find a Dieselmeken video on how to do the shaft seal. He doesn't mention the perimeter seal. I did the shaft seal and still had leaking. Dumped the ALDA in a bucket of water and attached a hose and blew and found the perimeter seal leaking on all 4 sides. Installing a fresh O-ring seal for the perimeter seal made the ALDA gas tight, even holds a vacuum now. With it working as designed, the engine can be tuned lean and still make plenty of power. I suspect all of the ALDA adjustments people make on their cars is to compensate for seals leaking and not functioning properly. Smoke ≠ Power.

Diseasel300 · #57 09-08-2017, 11:12 PM

I made some minor adjustments to the IP today, I had it a bit TOO lean. Steep hills were a problem and the low RPM power wasn't satisfactory. High RPM felt strangled. All noise and no power.

I gave 2f about 1/3 turn CCW and gave 2m another 1/2 turn CW. I figured since I was in there, I may as well get the RPM limit up where I want it. My RPM limiter is now ~5200 and the power is much improved. Off-turbo power is satisfactory now and if you lead foot it, the car seems like a rocketship compared to how it's driven since I put it on the road last year. Smoke is still nonexistent so I'm happy.

Fuel consumption numbers aren't available yet, but it's definitely improved compared to before. Prior to adjusting the IP 125-150 miles would have me at 2/3 tank on the fuel gauge. I clicked over to 130 miles since filling up this afternoon and I'm still right at 3/4 tank. Mostly stop/go traffic and back-road driving. I haven't been kind to the skinny pedal either. Once some diesel is available in this area I'll fill up and run the numbers.

Diseasel300 · #58 09-09-2017, 03:37 PM

Accidentally found a station with Diesel this afternoon, so I figured I'd top up and run the fuel economy numbers.

They seem like a definite improvement. 135 miles on 5.68 gallons. My math puts this at 23.77mpg, all stop/go "city" traffic and hilly back-roads. Keep in mind I've been romping pretty hard on the accelerator monitoring for smoke and undesirable behavior.

Considering I've seen the fuel consumption down at 16mpg with city driving, that is a HUGE improvement! Since I did some IP adjustments yesterday, the car seems to have WAY more power. Usage of the accelerator is much reduced as a result. I'll keep an eye on the fuel consumption and drive like a normal person and see where it levels out.

Maxbumpo · #59 09-12-2017, 02:07 PM

Thanks for all the follow-up! This thread is very inspiring to me, I really need to make some time in the garage...

Diseasel300 · #60 09-12-2017, 03:35 PM

I've used Google so many times for help and it always comes down to how well the thread was documented. I figure at some point in the future someone will have a similar problem to mine and Google will land them in this thread. I figure for those people it's worth updating the thread and giving realistic results.

The car has been running so much better after doing the IP tuning. The rough/lumpy idle issues are completely gone and haven't come back. The loud clattery idle is gone, and the power is so much smoother. With the way things were it was a very rough and unrefined car to drive. Amusing, but not very comfortable. Now it's driving like a proper S-Class with the added benefit of no longer dragging around it's own smoke screen!