Hey guys, thanks in advance for your help.

0-60 time is about 13.5 seconds, not bad, but slower than I want.

Turbo produces 10-11 PSI (WOT, under load, 4k RPM), spins by hand, no play.

Removed ALDA. Lots of black smoke above three quarters throttle above 3K RPM.

Wastegate door moves fine (when disconnected), actuator actuates with compressed air.

New aircleaner, clear passages to turbo fresh air inlet (door under aircleaner opens fine).

EGR disabled, cat cleaned out. Cat was pretty plugged up.

Noticed that there is a some black sludge in the intake manifold when I removed the ALDA fitting and a plug.

Did a diesel purge, changed filters. There's some crud collecting in the primary filter. But I think that's a separate issue from my low boost.

What else can I check?

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1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]

check for a shop rag in the inlet plumbing...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

inlet plumbing (pre-turbo at least) is clear

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1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]

Luke
Adjust your waste gate, DIY links Diesel turbo section has instructions for Garret turbo, KKK is easier, just loosen nut, screw it down a little. I did it on my 85 SD and it's quicker and cleaner, less soot.
Paul

I'll probably test the wastegate opening pressure first. It may be fine (and I suspect it is), in which case there is another problem, that I'm hoping someone on here can point me toward.

__________________
1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]

testing opening pressure is part of adjusting it, if it were i, i would go a few lbs over stock remember black smoke means you are over rich add boost to compensate.

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1996 s10 zr2 with a 6.5 turbo diesel
1996 c2500 suburban with a 6.5 turbo diesel
1981 300sd with a turbo 617
Monte carlo figure 8 car

Josha37 - thanks for your comments. I am just concerned that bumping the wastegate opening pressure is just masking another problem. If it opens at 15 PSI (or whatever the spec is), then that means the turbo is doing its job and the problem is somewhere downstream.

I'm hoping someone can point me toward what problem areas to check when turbo pressure measured at the manifold is lowish (10 psi).

__________________
1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]

Luke
if your blowing black smoke at 3k rpm @3/4 throttle with 10-11 psi of boost your waste gate is opening at 10-11 psi, fuel boost and power are pouring out the exhaust. Tighten the waste gate down one turn. Go for ride see what happens, check your boost, power, and smoke. If boost is too high back off the throttle and turn the waste gate back a half turn. Your probably going to need 2 or 3 turns.

I would if it were that easy, but unfortunately, I have the garrett, which means to do so I need to put some kind of restricter in the pressure line from what I've read unless there's a easier way I have yet to hear about

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1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]

Don't you already have a boost gauge in place? That's the pressure line thing. Opening and closing the WG does not look like a big deal on the garret, yes the kkk was easy. Waste is opening on too low a psi.

Im sorry, its a diesel want to know why the boost is to low? not enough fuel oh wait it is coming out the exhaust. The spring in your wastegate is weak and your manifold pressure is to low. fix it.

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1996 s10 zr2 with a 6.5 turbo diesel
1996 c2500 suburban with a 6.5 turbo diesel
1981 300sd with a turbo 617
Monte carlo figure 8 car

X2
adjust the waste gate

The garrett wastegate adjusts fine, I've got mine set at 18.5psi.

You will need to remove the clip on the turbo end, loosen the lock-nut, shorten the rod, re-tighten and re-clip. You might need a little pressure to extend the wastegate actuator against the spring while you're slipping it back on the arm, and this is much easier if you remove the air-filter assembly and heat-shield between it and the turbo.

Although it might benefit from more boost, you're not far off of the original 0-60 (in fact about right), and the black smoke shouldn't happen unless it's just blowing the exhaust clean.

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Gone to the dark side

- Jeff

Thanks gents, I'll give it a shot.

Cheers!

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1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]

Maybe you can test the wastegate theory by pulling the pressure line off the wastegate and go for a drive.

I spliced a manual boost controller into that line. And set it for about 14psi.

This solved my problem of wastegate opening too soon (weak spring). I didn't have to touch anything else on the turbo.

Something to consider anyway... cost $20

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Cheers!
Scott McPhee

1987 300D