I have owned this 1987 300sdl for about 3 weeks and 500 miles now. The mileage is 175000. In general I am very happy with performance. So far I have had the Trap oxidizer removed, changed the oil, changed the fuel filters twice, once before the diesel purge and once after. I have also cleaned all lines associated with the ALDA. Oh and changed the serpentine belt, courtesy lights, broken head unit and speakers and I know none of these last things are relevant. Anyway 60 mph and 2500 rpm seems to be a lousy speed. Below that I have decent power, 3000 RPM and above power is great. On a slight hill at 2500 it just will not accelerate. It just spews out black smoke and sits there. If I floor it the car will downshift and take off fairly well. If I hit the same hill at 70 MPH the car will pull the hill easily at half throttle. All of this would not be a problem if I lived somewhere else but around here almost all of the speed limits are 55.

Air restriction or lack of boost. Check your air filter and intake tract. If those are ok, I'd put a boost gauge on and monitor boost under the problem driving conditions. Anyone have a full load boost chart for a 603?

Or it might be a transmission tuning issue and it should be downshifting earlier. I've never driven a 603, so I'm not sure what the power curve is supposed to look like.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

x2

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Thanks, I will check the air filter but was told has less than 1000 miles on it. Thing is, full power is good so if I floor it and let it downshift it wakes up.it is just between like 2500 rpm and 2800 rpm in top gear. It did it today in a lower gear, kinda had a big turbo lag hole at 2500 rpm and black smoke then bam, took off. It has the EGR still hooked up. I was wondering if this is getting stuck open and somehow bleeding boost. I stuck a nail in the line tonight to see if it makes any difference.

By 2400 rpm full load you should be making at least 12 psi. Max factory allowable boost is 14psi.

Odd that there's a ton of smoke: If the alda is working right it only gives enough fuel to make smoke when the boost comes up. Get a boost gauge on there and see what's going on.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Blah on the boost gauge. I don't really want a permanent gauge in a 300SDL and I will look like a hill billy with a temporary one hanging out of the hood in the car. I will do it if I have to.
I am surprised that it is supposed to make full boost at 2400 rpm. driving the car it feels like full boost comes on around 3000rpm. Max rpm in lower gears is around 5200RPM.
When it happens there is enough black smoke that I have seen cars behind me swerve to avoid it, not more than a hopped up dodge truck but enough to see it easily in the rear view mirror.

On mine, I found on hills that 2500 rpm was just the beginning of the power band, and had a similar thing to it. I simply took the ALDA off, and the problem went away.

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All it takes for evil to prevail is for good men to stand by and do nothing.

Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic

Did talking the ALDA off impact fuel economy? I assumed if it was blowing black smoke then more fuel wouldn't fix it and that taking the ALDA off would increase fuel. Thanks for confirming what my butt tells me that 2500 is where power begins on this model.

It didn't seem to effect fuel economy much on the highway. In the city, if I didn't watch it, it would blow piles of black smoke out the rear, and would almost chirp the tires, even with an extra 300 pounds in the back... There are more than a few kids in hondas that never want to race me off stop lights again... lol
But i did have the fuel load adjustment screw opened almost to the max...
You might have to time the injection pump.
Even thought the charts say one thing, the power from the turbo only comes in at 2500, after that, there is a lot of power.
Before I kinda retired my ride there, I was looking into putting on a vnt turbo from a dodge truck, or a sprinter van... Never got that far though...

__________________
All it takes for evil to prevail is for good men to stand by and do nothing.

Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic

So maybe I should try tweaking the ALDA first. Thing is it does seem like something is getting stuck. It did it today in a lower gear and when it hit 3000 it was like a whack in the back of the head with a bat, The power just instantly turned on. Normally power comes on very smooth. Oh and it isn't like I got extra power, it was very flat and lots of smoke first like super turbo lag.

possibly the air box below the air filter is stuck shut. Check to see if the turbo spins freely...

__________________
All it takes for evil to prevail is for good men to stand by and do nothing.

Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic

Just hook up a temp boost gauge. Run it through the gap between the hood and the firewall, through the driver's side window, and hold the gauge. You just need to figure out what the car is doing.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Drive a different 300SDL and compare. In the back of my mind I wonder if you aren't just expecting more of the car than it's capable of. These have got several "dead" zones in the power band... the automatic transmissions upshift on the "granny" schedule and then you go to accelerate and suddenly there's no power.

55 is an awkward speed in my experience for a 300SDL. It's right at the top of 3rd gear and right at the bottom of 4th gear so there's no power available in either place. 4th gear doesn't start "pulling hard" until 65-70 mph, and 3rd gear tops out at 55-60 and quits pulling hard a tad before that. You're trying to get the car to be peppy at one of its "in between, never meant to do well there" spots, in my opinion. There may be nothing wrong with it.

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~Michael S.~
Past cars:

1986 300SDL
1987 300SDL
1982 240D
1982 300SD


Current:

1987 300SDL

If your 300SDSL gets stuck at 60, and that bothers you, take it out of first gear!

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Strelnik
Invest in America: Buy a Congressman!

1950 170SD
1951 Citroen 11BN
1953 Citroen 11BNF limo
1953 220a project
1959 180D
1960 190D
1960 Borgward Isabella TS 2dr
1983 240D daily driver
1983 380SL
1990 350SDL daily driver alt
3 x Citroen DS21M, down from 5
3 x Citroen 2CV, down from 6

If you're getting smoke, you already have excess fuel, so it's not the ALDA.

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1981 Mercedes 300TD, 1994 Honda Civic Del Sol
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