OK so yes there are a million threads on the ALDA, but I need some really basic help with the name of parts related to the ALDA on the 603 engine. I haven't found anything where people talk about this basic stuff. I have the FSM, but can't find anything in there either. If it's there, maybe somebody could point me to the right location?

I'm basically trying to get my "slow off the line" problem fixed and the first place I'm going for is ALDA adjustment/cleaning. I just looked at Diesel Giant's ALDA Banjo fitting cleaning guide, but of course it didn't help me since it was on a 617, but still, I need something like that for the 603.

I'm not going to remove the ALDA, at least not just yet. I first would like to make sure all the ALDA related stuff is working properly, then adjust it (if I need to), then if that still doesn't make me happy I will permanently remove the ALDA.

So with all that in mind, I took some pics of ALDA related components on my engine, spent some time highlighting the stuff I have questions about and was hoping I could learn something. Without further ado, the pictures...

Showing the ALDA, and related lines. I have oil (or something) in these lines, should I?


What is this contraption that the line from the intake and one of the two lines going to the ALDA connect to?


One of the lines from the ALDA leads to this mess of stuff, what is this stuff?


Thanks so much.

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-justin

1987 300TD, 1987 300TD
2008 R32, 2000 Passat Wagon

The item in the second photo is the overboost protection switchover valve. In the event of too much boost in the manifold, the switch (you can see it on the bottom of that switchover valve) closes the valve and prevents the boost signal from reaching the ALDA through the line that comes out of the switchover valve. If the switchover valve gets clogged or stuck shut, then you get no signal to the ALDA, hence no fuel increase and no effective boost. Since there is carbon gunk in your lines, there is likely some in the valve, too. You can clean the lines, but I would just replace them. They become brittle with age and are dirt cheap to replace. Now, the valve itself, I also replaced .. but at $50 you might want to try to test/resurrect the one you have. From what I understand it isn't easy to clean, but can be done with compressed air (someone can elaborate on that). Anyhow, that crud in your lines is common, but not desirable. Mine were actually worse than that, as in they were entirely black. When I replaced tham and the valve the car got noticeably more spritely. And I wasn't even really having a boost problem to begin with (I just felt like doing a project and noticed how dirty the lines were). I would give that a try. It could make a huge difference and you won't have to tamper with the ALDA.

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1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

The contraption is the switchover valve. The thing with the blue cap is a vacuum amplifier.

I'm doing exactly the same thing today, there is no way your car is as sick as mine. try taking the switchover valve and lines that go from it to the intake and the ALDA and clean them all out good. This may be your issue.

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87 300D Turbo (still wondering about #14 head)
98 Buick Regal GS (one quick grocery gettr)
07 Honda CBR1000RR
04 Dodge Ram Laramie 4x4 CTD (heaven)
95 Dodge Ram 3500 CTD. Need snow plowed?

Ok cool, I'll get some new lines and *try* to clean that valve. There is LOTS more gunk in those lines when the engine is running or recently turned off, I just disconnected the line that goes from the intake to the valve with the motor running, thinking I could somehow suck the gunk out of the lines. Despite revving up the engine a bunch, the gunk in the lines did not move.

__________________
-justin

1987 300TD, 1987 300TD
2008 R32, 2000 Passat Wagon

I just cleaned mine all out now and replaced them.... little boost in performance. I put 50lbs of air on my rubber tipped air blower and blew both directions on the switchover valve. I think I need to clean the line that goes from the switchover to the ALDA better... I couldn't get it off the alda without cutting it and I didn't have new lines.... what happens if you just unhook and plug that line?

Does the ALDA just allow fuel enrichment all the time?

How does the IP know when to enrich fuel?

__________________
87 300D Turbo (still wondering about #14 head)
98 Buick Regal GS (one quick grocery gettr)
07 Honda CBR1000RR
04 Dodge Ram Laramie 4x4 CTD (heaven)
95 Dodge Ram 3500 CTD. Need snow plowed?

If the ALDA does not get a boost signal from the lines, the IP does not know to up the fuel. The net effect of the turbo boost will be zilch there isn't the increase in fuel to meet the increased air density. If you disconnect the lines, then no signal can get to the ALDA, i.e., you will never get an increase in fuel whether there is a boost condition or not. If you bypass the switchover valve and connect that line from the intake straight into the ALDA, it will perform exactly as it would with a properly functioning overboost circuit ... with one exception. If there is an overboost situation, nothing will stop the ALDA from increasing fuel and you will end up possibly toasting your engine. That overboost protection circuit basically allows the ALDA to increase fuel to meet boost whenever it is called on ... the only time it should prevent that is in the case of an overboost situation (wastegate failure). If you bypass the switchover valve, there will be nothing to block an overboost sitatuation. But under normal functioning conditions, it will do the same thing whether bypassed or not: an increase in boost is communicated to the ALDA via the line, and the ALDA triggers the IP to deliver more fuel. Blockages in those lines or in the switchover valve can prevent that signal from ever getting to the ALDA.

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

Thanks for the info. I think I'll cut the switchover valve out of the circuit tomorrow for testing purposes. If that bost is hooked up directly to the to the alda and I get a serious boost in performance then we are going to switch that silly MB over to a strict diet of B100....


Could I use regular vacuum hose to replace those items? what size?

__________________
87 300D Turbo (still wondering about #14 head)
98 Buick Regal GS (one quick grocery gettr)
07 Honda CBR1000RR
04 Dodge Ram Laramie 4x4 CTD (heaven)
95 Dodge Ram 3500 CTD. Need snow plowed?

Justin

If you have that much junk there are a few things you can do to lessen the chance of reaccummulation after you have cleaned the lines. Take the crossover pipe and intake manifold off and clean both well. Disable the EGR, and run Mobil 1. Any of those steps will help reduce the amount of gunk that can get dumped into those lines. I took the ALDA off yesterday and adjusted it just a 1/4 turn and there is a noticeable difference. I am going to have at it again this weekend. I followd gsxr's instructions but I was not able to budge the nut with channel locks so ended up using an open end wrench. I also needed to loosen fuel lines 4, 5, and 6 from the injection pump. My car was dead slow off the line, especially when cold.

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=-=-=-=-=
1987 300TD 231,000
#22, afterglow, plastic fan, euro lights, alternator upgrade, cluster housing update

One step ahead of you my friend. A month ago I removed the EGR (used EGR delete kit courtesy of Mr. Carlton), removed the intake and crossover and cleaned them out, ANDDDDD put my 603 on a strict diet of Mobil Delvac 1.

I cleaned out the lines today, will get to the valve this weekend and then probably adjust the ALDA out a bit.

__________________
-justin

1987 300TD, 1987 300TD
2008 R32, 2000 Passat Wagon

Good deal. I did that all last spring and happened to pull the crossover a week ago and there was remarkably little grime.

__________________
=-=-=-=-=
1987 300TD 231,000
#22, afterglow, plastic fan, euro lights, alternator upgrade, cluster housing update

Justin,
Did you get your problem resolved with your ALDA on the 87?

__________________
87 300D Turbo (still wondering about #14 head)
98 Buick Regal GS (one quick grocery gettr)
07 Honda CBR1000RR
04 Dodge Ram Laramie 4x4 CTD (heaven)
95 Dodge Ram 3500 CTD. Need snow plowed?

Jim what I think you should do is remove your ALDA and plug the hose going to it. If there is a difference, then there you go. No ALDA and the IP thinks full fuel all the time. If you measured boost pressure inline after the switchover valve, and you are reading little to no boost, then the switchover valve is bad. Take your reading before the switchover valve inline. As a matter of fact take your reading at the plug in the intake(I think there is already a tapped hole in the intake for this purpose). Your ALDA could be busted, your switchover valve could be dead. I myself had both problems+ dead boost pressure sensor. Finding out I had a broken ALDA, which was not immediately apparent, took me 4 years (I had never thought to pressure test, I assumed it worked because the screw turned- DOH!). If the tamper-proof cap is still intact it is likely that the ALDA is still good. If it's been torn off it's likely a PO or some other hamfist turned the screw out too much and busted it. I just found out yesterday that my car was fast. Keep at it, you will find the problem. It's not supposed to be a dog. Especially yours- the '87s are real quick.

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'02 BMW 325i
'85 300D 450k
'93 190E 2.6 170k(killed by tree)
'08 Ducati Hypermotard 1100S 6k
'06 Ducati S2R800 14k(sold)

No. I cleaned out the lines, but that didn't do anything for me. I never go around to taking off the overboost protection valve and cleaning it due to some house projects that got the best of my weekend.

Still doggishly slow off the line.

__________________
-justin

1987 300TD, 1987 300TD
2008 R32, 2000 Passat Wagon

Real quick? I'd get out run by a vespa in this turd!!!

I'm going to try the ALDA removal as soon as I get a chance. I'm hoping that fixes it... next course of action is to cut out the stupid cat.

__________________
87 300D Turbo (still wondering about #14 head)
98 Buick Regal GS (one quick grocery gettr)
07 Honda CBR1000RR
04 Dodge Ram Laramie 4x4 CTD (heaven)
95 Dodge Ram 3500 CTD. Need snow plowed?

Before you remove the ALDA. tell me, have you taken a boost check while driving (attempting to drive it)? You may not have enough boost in the first place. Check it at the small hose barb on the side of the manifold where it goes over to the switchover valve. Run a pipecleaner thru there too to be sure its got a clear passageway too.

I started a 603 that I had the crossover pipe removed and it would hardly get out of the way of a snail. If your wastegate flapper is stuck open like one of mine was, you also have what is basically a sick running car, it will eventully get up to 40 MPH but after a long while and some dark smoke all the while. These babys really need lots of air to run right. When you get it right we want to see the smile on your face

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!