i timed my 0-60 today and it waqs like 17.8 seconds. I have a 300sdl and i heard that it should be around 11-12 seconds. I have a boost gauge that reads about 12.5psi and the motor revs to about 48 4900 before it shifts out of gear when you floor it, i removed the alda and that helped the off idle accel a little bit. I purged it today, im going to change the oil tonight but does anybody have any ideas what i could do to make it run faster, how do i adjust the throttle linkage or how do i kno if it needs to be adjusted? what about the egr? can i use metal that tin snips can cut to make a plate to cover my egr when i remove it? does anyone kno what it could be thats causing my car to be slow?? it kinda seems like its not reving up as fast as it should be.

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1985 mercedes benz 300D turbo diesel
1998 VW GTI VR6
1996 VW GTI 2.0
1999 saab 9-3 turbo
1987 300sdl (sold)

does it smoke like crazy when you floor it with no alda? If not then I'd try new fuel/air filters and make sure your tank strainer is clean. I'm sorta in the same boat with my 300D, its around 15 seconds for me. I'm leaning toward a partially clogged exhaust, I may try and check next.

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1980 500SE/AMG Euro
1981 500SEL Euro
1982 380SEL
1983 300TD
1983 500SEC/AMG Euro
1984 500SEC
1984 300TD Euro
1986 190E 2.3-16
1986 190E 2.3
1987 300D
1997 C36 AMG
2003 C320T 4matic

past: 1969 280SE 4.5 | 1978 240D | 1978 300D | 1981 300SD | 1981 300SD | 1982 300CD | 1983 300CD | 1983 300SD | 1983 380SEC | 1984 300D | 1984 300D | 1984 300TD | 1984 500SEL | 1984 300SD | 1985 300D | 1986 300E | 1986 560SEL | 1986 560SEL/Carat | 1987 560SEC | 1991 300D 2.5 | 2006 R350

Search around on the forums, this sympton has hit a lot of folks with 603 engines. A very common cause is the boost signal from the turbo gets blocked on its way to the Alda. So no boost signal, no extra fuel. The turbo is making pressure but without fuel there is no additional power.

A pressure line comes from the turbo side to a device called the overboost protection relay that sits on the driver side fender well. The pressure line then goes to the ALDA signalling it to add fuel.

Check this pressure line path to insure it is not blocked. You can bypass the overboost relay for a while to test.

Chuck

All unrelated to the discussion.

The ALDA is removed from the IP.

My only additional comment is that the linkage to the IP must be not in proper adjustment and full fuel is not being provided by the IP.

If this proves false, the timing might be checked to see if it's wildly out of spec..........however, with a time of 18 seconds...........I'd make a bet that the IP is not providing the proper delivery at maximum fuel conditions.

how do i check the linkage? do i tighten the throttle wire or do i have to have sombody step on the pedal to the floor and see if i can move it up more under the hood? the alda is off and when i floor it it smokes black alot, i noticed the line that goes to the egr is plugged and the thing that it goes into that, is by the airbox it has 2 or 3 vac lines coming out of it and there are screws in both of them, could that have an effect? when i floor it even with the alda off it still seems a little sluggish with 288k hopfuly i just need to tighten the linkage but id need some advice on how to do that.

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1985 mercedes benz 300D turbo diesel
1998 VW GTI VR6
1996 VW GTI 2.0
1999 saab 9-3 turbo
1987 300sdl (sold)

The fact that you get black smoke on launch indicates that you're getting the fuel that is required by the engine. Therefore, I conclude that the linkage is working properly.

This leaves you with a more complicated problem. It's time to check IP timing and see if the chain is unduly elongated..........although I seriously doubt that the timing could affect the acceleration with such magnitude.

With 288K, I might consider a compression test.........just to see if the numbers come up lower than expected.

How does it perform on a cold start and what are your ambient temperatures there? Does it kick and bang for an extended period?

What's the fuel economy?

Are you sure there is no air restriction from the intake and through the turbo?
Air filter is clean?

Brian / all:

"All unrelated to the discussion.

The ALDA is removed from the IP."

Good point, the ALDA can't add fuel if it isn't there. I think his comment was 0-60 was slow. From a start the boost won't be there until the turbo kicks in... 2000, 2500, 3000 rpm- whatever. So from a start the ALDA would have no effect. At the top of first gear, once boost happens the engine needs more fuel to make more power, it has the air. With no ALDA, can the IP provide the extra fuel?

Again my question relates to what I observed when my ALDA was in-op due to the plugged pressure line, I had boost, I had full throttle movement to the IP, but just not enough fuel to make HP in upper rpms. At highway speeds I would downshift from 4th to 3rd, the rpms would go over 4000, but no appreciable increase in hp. Fixed the ALDA signal and then the HP increase came back. 0-60 went from 19 seconds to around 12. The off idle remained the same either way.

So one course of action might be to replace the ALDA, check the boost line - maybe with a guage t'eed in, and see if it helps upper rpm response. I may be wrong again also. It is great to share ideas and theories back and forth, it is a great way for us to learn!

Chuck

You need to understand how the ALDA functions from the ground up.

Consider it a "fuel limiting device"...........not a "fuel enrichment device".

It presses down on a small plunger and limits the fuel that the IP can provide. If you remove it altogether, the plunger lifts up and the IP is unrestriced for fuel.

If you keep it in place and the unit does not function due to clogged lines or a defective or leaking diaphragm, it won't lift the plunger and the IP will be restricted as to the amount of fuel it can provide. When functioning properly, the ALDA lifts the plunger depending on the amount of boost pressure that it receives. The range is typically 0-12 psi, but, it varies depending on the specific vehicle and the preload that is present in the ALDA.

Remember that in all of this discussion, the driver's foot is controlling the same device that the IP is controlling..........the rack. The driver will advance the rack with his right foot. The IP will provide more fuel when he does this all the way up to the maximum fuel amount. The maximum amount will be restricted by the ALDA until it sees boost. If the ALDA is removed completely, this restriction will not occur and the driver can generate some black smoke on heavy pedal below boost levels.

the car does make sum noise when its cold but it also only has 2 good glow plugs working right now, how do i check the ip timing? could this b a vacuum related problem?

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1985 mercedes benz 300D turbo diesel
1998 VW GTI VR6
1996 VW GTI 2.0
1999 saab 9-3 turbo
1987 300sdl (sold)

You'll need the RIV lights to check timing on the vehicle. I believe that MB Doc still rents out his unit.

The problem is unrelated to vacuum.

god two plugs working and it still starts when cold? i'd venture your compression is good

__________________


1980 500SE/AMG Euro
1981 500SEL Euro
1982 380SEL
1983 300TD
1983 500SEC/AMG Euro
1984 500SEC
1984 300TD Euro
1986 190E 2.3-16
1986 190E 2.3
1987 300D
1997 C36 AMG
2003 C320T 4matic

past: 1969 280SE 4.5 | 1978 240D | 1978 300D | 1981 300SD | 1981 300SD | 1982 300CD | 1983 300CD | 1983 300SD | 1983 380SEC | 1984 300D | 1984 300D | 1984 300TD | 1984 500SEL | 1984 300SD | 1985 300D | 1986 300E | 1986 560SEL | 1986 560SEL/Carat | 1987 560SEC | 1991 300D 2.5 | 2006 R350

It presses down on a small plunger and limits the fuel that the IP can provide. If you remove it altogether, the plunger lifts up and the IP is unrestriced for fuel.

I thought it is:

the further down the plunger goes, the more fuel is delivered...???

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1983 300SD, 1999 200 cdi and 1998 1,6 (gasser)

Negative.

Brian,

Thanks for taking time to explain the details behind how it works. I'm learning more each time.

Chuck

Anytime.

Help is what we do here.