Rebuilt turbo, new manifold gasket, 8 lbs of boost. Not any noticeable power increase - Page 3 - PeachParts Mercedes-Benz Forum

gregp1962 · #31 03-23-2019, 04:01 PM

OK, I went out to switch the hoses to bypass the switchover valve and the plastic hoses are hard as rocks. What is the best way to detach and reattach without cracking them? Gentle heat with a heat gun?

BTW, when measuring 0-60 in my car I find it more appropriate to use the minute hand on my watch rather than the second hand.

tyl604 · #32 03-23-2019, 11:10 PM

If you use a small screwdriver, you can probably push the plastic/rubber hoses off the nipples.

vwnate1 · #33 03-24-2019, 10:59 PM

Those plastic pipes are hard, that's why there are sort rubber bits at the switchover valve, just pull straight away from the valve, gripping the rubber .

originally the rubber bits had clamps to prevent them from blowing off under heavy acceleration .

Remember : you need to connect the boost pressure gauge at the ALDA and no where else so you'll get the actual amount of pressure reaching the ALDA....

? Did you suction test the ALDA yet ? .

Bengoshi2000 · #34 03-25-2019, 06:26 AM

Take an exacto knife and slit the rubber hose first. I broke a nipple on my VCV trying to pull the old rubber off.

gregp1962 · #35 03-25-2019, 03:36 PM

I didn't suction test the ALDA. But, I did bypass the switchover valve and it's not any better. Tomorrow, I'll test the ALDA and I'll attach the pressure gauge at the ALDA as suggested.

If I remove the ALDA should it get enough fuel? I guess I'm confused. Does the ALDA add fuel under boost or does it limit fuel until a boost signal is received?

Diseasel300 · #36 03-25-2019, 04:03 PM

The ALDA limits fuel until a boost signal is present. Removing the ALDA runs at full enrichment all the time.

ROLLGUY · #37 03-25-2019, 04:18 PM

Quote:

Originally Posted by Diseasel300

The ALDA limits fuel until a boost signal is present. Removing the ALDA runs at full enrichment all the time.

I like to limit the coal, so I usually just back out the adjustment all the way (counter-clockwise till it won't go anymore). That way, the boost signal adjusts the fuel up to the maximum.

vwnate1 · #38 03-25-2019, 04:56 PM

DO NOT remove the ALDA ~ not now, not later, never .

You're trying to skip steps again and this will only ensure you chase your tail until you get pissed off and junk the car and blame it instead of poor work habits .

You cannot make any mixture changes until it gets at the very least, factory boost of 12 # .

I know this isn't what you want to hear but there are NO SHORT CUTS .

Either do it 100 % right or bail out now and sell the car before you want to set it on fire .

This is why some of us here drive our old MB's daily and sometimes (me anyway) balls to the walls and don't have smoke billowing out the back or poor road performance .

This isn't your high school Camaro where you can slap a too big carby on the 350 V8 and advance the timing until it pings and spin the tires until they shred ~ this is a delicate finely engineered automobile and unless you take sharp care of it, it will be a bleeding pain in your rump and drain your wallet .

Time to ***** or get off the pot .

gregp1962 · #39 03-25-2019, 05:55 PM

Well, I don't want any coal from the exhaust pipe. If the ALDA were useless like the EGR, I'd just remove it. Sounds like that isn't case.

ROLLGUY, when you say "back out the adjustment". you're talking about the screw on the ALDA, right?

BTW my high school "Camaro" was a Mustang.

vwnate1 · #40 03-25-2019, 06:38 PM

? was it a 289 or i6 engine ? .

Diseasel300 · #41 03-25-2019, 06:41 PM

You're troubleshooting. Not bypassing things. Pull off the damn ALDA and go for a drive. You're not going to damage anything, you're not going to burn anything up, you're not going to harm the engine. If there's no change in how it drives, either something is stuck in the IP and not enriching fuel, or something else is wrong. If removing the ALDA makes a profound difference in how the car drives, we have something to go on and can guide you further.

You haven't mentioned if pressing the pedal to the floor moves the throttle lever against the hard stop on the back side of the IP.

Dan Stokes · #42 03-25-2019, 08:42 PM

As far as making power.... I removed the ALDA as an experiment on my OEM pump on my OM617 (the pumps are similar) in Mutt the Race Truck and achieved ZERO performance increase as measured on the track with highly precise timing equipment. I suspect that the so-called "performance advantage" is psychological based on increased black smoke.

I agree that one COULD pull the ALDA as diagnostic tool but I'd be surprised if you got any difference (though I've been wrong before......). However, getting the boost back up to spec is likely to increase performance - the more I crank mine up the faster I go with my last track pass yielding 136.2 MPH (25PSI boost pressure). Note that this is with a Dieselmeken pump and the biggest elements he made at the time I bought my pump. The Dieselmeken pump is coupled with some high output injectors that I got from our resident injector Guru.

Best of luck resolving this!

Dan

Diseasel300 · #43 03-25-2019, 08:48 PM

Quote:

Originally Posted by Dan Stokes

As far as making power.... I removed the ALDA as an experiment on my OEM pump on my OM617 (the pumps are similar) in Mutt the Race Truck and achieved ZERO performance increase as measured on the track with highly precise timing equipment. I suspect that the so-called "performance advantage" is psychological based on increased black smoke.

I agree that one COULD pull the ALDA as diagnostic tool but I'd be surprised if you got any difference (though I've been wrong before......). However, getting the boost back up to spec is likely to increase performance - the more I crank mine up the faster I go with my last track pass yielding 136.2 MPH (25PSI boost pressure). Note that this is with a Dieselmeken pump and the biggest elements he made at the time I bought my pump. The Dieselmeken pump is coupled with some high output injectors that I got from our resident injector Guru.

Best of luck resolving this!

Dan

If the boost signal isn't making it to the ALDA, you can bet your bippy there'll be a BIG improvement in performance by removing it for testing. If the ALDA is working properly and boost signal is making the trip, there should be no appreciable difference in performance.

Remember....boost is also built with fuel. If the ALDA is not functioning properly and there simply isn't enough fuel being injected for the engine to do adequate work, the boost pressure can be low as a result.

If the OP removes the ALDA for testing and finds he just rolls coal without any improvement in acceleration, it's time to look elsewhere.

There's a method behind the madness. Eliminate one variable and test the system. Evaluate the results. Determine if your variable elimination made any difference. If it did, determine WHY it made the difference. If it didn't, determine what the next variable you want to eliminate.

gregp1962 · #44 03-25-2019, 11:14 PM

Thanks. for diagnostic purposes, I'll probably remove the ALDA. I just don't want black smoke for any amount of time. Hopefully, I'll have time tomorrow. Is it a pretty self explanatory process to remove it? Looks pretty simple.

The Mustang was a 1965 289. I gotta say, that V8 engine was more robust than these OM617s. My '65 Mustang's temp gauge didn't always work. I knew it was overheated when the engine died and steam came out of the grill. I would Let it cool down and drive it to get more water. Now THAT'S a bulletproof engine. Compared to that, the OM617 is a delicate snowflake.

Squiggle Dog · #45 03-25-2019, 11:59 PM

Haha, I removed the ALDA on both my and my roommate's cars. I've never had a problem with my car spewing out smoke. When I run biodiesel none seems to come out at all. But, it may or may not be the issue here.