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bigblockchev 09-12-2011 11:22 PM

87 TDT black smoke all the time
Here is what I know
Just bought this yesterday got towed home
Started easily after sitting for a year or so
Black smoke all the time lots of it at idle and under power
Significant nailing noise
Would not move up hill at all
did diesel purge & half the nailing cleared up within 30 secs but still smokes
after the diesel purge it would accelerate, possibly normally at least much better
Checked compression 440,440,480,460,440,440 after approx 1 hr on the block heater, not possible to let it run up to temp by itself just too much smoke.
Pop tested injectors all were in the 2000 psi range one was 1950 reasonably good pattern. old style injectors with the threads up at the top.
disconnecting the EDS plug at the back of the IP made it not possible to start without foot on throttle & would die if you let off
Drained fuel and replaced with 100%Bio, still the same
ran off small container in the engine compartment after doing diesel purge
still smoked.
Checked air cleaner, fairly clean, disconnected turbo crossover tube still smoked.
Removed Alda in case it was causing problem same smoke with or without Alda installed.
I am thinking Injection pump since the nailing improved substantially with the diesel purge, but would like to check everything else first before removing that.
I was also wondering if the timing device was frozen in one spot. What effect would that have on smoke production.
I will attempt to check the timing tomorrow but if it was really off I would expect the pistons to hit the valves or some such.
Did the oil cap rattle test for blowby
Previous owner said this came on fairly suddenly but it was a year ago so his memory might not be that good

Have I missed something?
What to do next?

Aquaticedge 09-12-2011 11:25 PM

check to see if anything made a nest in the intake tube, check to see if your turbo spins, Check the boost lines between the turbo, Overboost valve and lines connected to alda, they plug with soot, check your intake manifold, they also can get gungy from EGR flow

netboy 09-12-2011 11:55 PM

X2 - sounds like your not getting air.

jonbobshinigin 09-13-2011 12:18 AM

Hook up a boost gauge and let us know what boost you are getting. If you don't have that right off your 0-60 time will tell us a bit too!
It clearly isn't getting air and is choked. It should idle easy when IP is unplugged. It defaults to 600 rpms if I recall correctly...mine doesn't struggle to run at that speed.

bigblockchev 09-13-2011 01:05 AM

smoke is bad
I would be embarrased to drive it around the black snake from the tailpipe is that bad. smokes out the neighborhood like a chipped Cummins with your foot in it. with the turbo crossover removed it should be not having any restriction from the inlet also no effect from the egr. I checked in the inlet to the head runners , not perfectly clean but not too dirty either. What I cant figure out is with diesels if you add fuel the rpms increase, since there is black smoke I assume that there is too much fuel even at idle. So why does it idle at all. I also tried cracking each injector nut one at a time and each one had about the same effect. I should probably remove the intake manifold just to make 100% certain it is not restricted in any way. Very puzzling to say the least. Cheers Dan

barry123400 09-13-2011 01:21 AM

When you pulled the number one injector was it oily compared to the others?
Or did you compression check with the glow plugs removed? With the number one injector out crank the engine to see if any oil is spit out that opening.

If so the head gasket may be weak as the oil feeder passage to the head is right by the number one cylinder. For the time it takes may be worth a look. Fairly common failure on these engines.

jt20 09-13-2011 01:23 AM

Broken timing device would not cause such terrible smoking alone. Its default setting is 0* of advance and increases to about 7* or 8* with RPM. Its design does not really allow it to get "stuck" in one position (but stranger things have happened). It is worth inspecting.

Strongly suggest re-timing the engine. Match the cam to the crank and adjust IP. You are right about the interference, but one tooth either way will not cause interference.

jonbobshinigin 09-13-2011 01:23 AM

Without the crossover you will have no restriction...but also no boost. Put it back on and check boost pressure. A turbo engine not getting boost will smoke...I am pretty sure anyhow!

jt20 09-13-2011 01:30 AM


Originally Posted by jonbobshinigin (Post 2789718)
Without the crossover you will have no restriction...but also no boost. Put it back on and check boost pressure. A turbo engine not getting boost will smoke...I am pretty sure anyhow!

The boost is what determines the extra fuel supply though. It should not smoke with zero boost. (emphasis on 'should')

At idle, boost is not a concern either.

jt20 09-13-2011 01:35 AM

It might seem backwards, but focus on the fuel supply once you get it timed.

filters, tank screen, lift pump and DV o-rings.

jonbobshinigin 09-13-2011 08:08 AM

I suppose I did overlook black smoke at idle, since that would have no boost regardless. I still vote for determining if it is making boost; it is afterall very easy. Timing would be the next thing I check.

kerry 09-13-2011 09:57 AM

Black smoke is unburned fuel . Usually that means not enough air to burn it. You don't mention whether the turbo is spinning or not.

barry123400 09-13-2011 11:12 AM

What acceleration is like might provide a clue as well.

Bogeyman 09-13-2011 11:23 AM

Plugged CAT?

bigblockchev 09-13-2011 01:09 PM

Still puzzled
1 Attachment(s)
Kerry with the turbo crossover disconnected it should not affect the idle smoke production.
Barry the acceleration is not terrible though again I am reluctant to drive it much.
Bogey I am going to investigate your idea , The only documentation that I have for the car is an invoice from 2007 for trap ox replacement. This blew me away as it appears that MBZ seems to have replaced the entire exhaust system and the turbo on a then 20yr old car. The exhaust does appear new front to back with the original shiny appearance of the piping. The mileage listed on this invoice is the same as what is on the car now. It appears that the odometer is not working but I am not sure how much use it got in the last 4 yrs. I include the invoice. I am wondering if they screwed up something when they did the trap ox like a piece of insulation or something got into the piping.

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