I have been working on this issue for months now and not much closer to solving the problem. It goes into no turbo boost within 2 minutes of start up. CODES P0400(P1403) and P0243
I have read the previous post by Turbodiesel (mercedesshop.com/shopforum/showthread.php?t=118125) that was started years ago and solved by some very good help from all and with a detailed post from Dr.Diesel
I have replaced parts, because of finding bad components. MAF, EGR valve assembly, all plastic fuel lines, intake manifold removed and replaced and cleaned, replaced all vacuum hoses, installed a boost and vacuum gauge, checked the pressure supply, wiring. I replaced the vent filters.
The EGR and Turbo pressure transducer are only showing 0.018 DC amps which is low according to Dr. Diesel.

??What causes this low current draw??
??What fuses protect these circuits so that I can check for fuse corrosion at the bayonet connectors??

During the first 2 minutes of operation I get 20 pounds of boost and the car is fast and after that time the boost is 0-3 psi and it is a dog!
The EGR valve had been opened up and the innards had been removed by a previous owner, but the turbo worked fine until I overheated it and it went into full limp home mode and I was put on the piggy back wrecker and brought home.
Wife drives it every day but I have the need for more power. I am about ready to send it to the dealership for a fix.
Am driving to Blythe this w/e so pass with care when you go past the non turbo E300.

Thanks in advance!
Larry12
1998 E300-606.962
1987 300-603.960
1993 8.3 TD Cummings

Check gsxr's thread on modding the 2.5 turbo wastegate to work off boost rather than vacuum. I don't know if the 606 has flaps or throttle plates in that maze of an intake manifold but I'll bet you can prop them open. This is all for naught if fuel enrichment is electronic rather than gool old mechanical ALDA.

For testing purposes, run a line directly from the engine vacuum pump to the wastegate actuator. Drive just aggressively enough to confirm that there is or isn't fuel enrichment. Note that nothing but sparing use of your right foot will prevent your engine from blowing up

Sixto
87 300D

Have you replaced the bleed filters on the EGR and turbo wastegate transducers? If not I would try that. I would get a CEL and loss of boost in cold weather from time to time until I replaced those filters. Since then all is well with the system.

Also, if you have not replaced the transducers themselves try swapping them and see if it makes any difference.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Getting codes for both tranducers is RARE. They both get power from the K40 relay. Have you replaced that relay?

Other than a bad relay the transducers are monitored for current draw. That is what would cause those codes.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

I did replace both bleed filters for the transducers.
I also swapped the transducers.

I did not replace the K40 relay.

I have put a vacuum pump on the turbo waste gate and pumped it to full open and the power still drops off.

I feel that that a fuel enrichment signal is not being sent.

I was checking the DC amps across both wires as they are both encased within a tube.
Should I separate the wires for my clamp DC amp meter?

Larry 12

I have now replaced the K-40 relay. Same problem!
Car runs 0-70 mph like a rocket. Second time it starts fast then boost drops to 0, it runs fast until I let off the pedal, then it is all slow from that point on.
Shut it off and let it sit for 10 minutes and it runs good again until I let off the pedal, then slow again. No boost or go fast.

Larry12

Larry,

The MAP sensor determines max fueling based on boost. If it's not hooked up, (I've done some experimenting with mine) the car runs and accelerates but it does so quite slowly.

Even with it totally disconnected from the manifold, it won't throw a code. I also hooked mine up to the pressure port on my mity vac to test it's response. When it was accelerating and sensing no boost, it was a dog. As soon as I squeezed the pump a couple times, it would charge ahead.

I'm wondering if there's something wrong with the MAP sensor or the quality of the boost signal going to it...

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

Bingo,
OK, something new. So much boost was generated that the "T" fitting to my boost gauge blew off at the MaP input.
No wonder the boost dropped of at the last test and it kept running great for a while.
Tie wrapped back on. Wife takes it to work in AM. I'll as her how it ran after she gets to work.

Thanks...Maybe on the right track.
I'll know at 0600.

Larry12

OK, I could not wait and went out to test in the dark!

With everyone's help and suggestions it is now a rocket all the time.
The K-40 relay was the last link to fix after the MaF,EGR valve, filter vents, leaky vacuum lines, radiator replacement, radiator cross member re-welding, intake manifold removal and cleaning, IP lines replacing...on and on.

I am a happy camper

Larry12
1998 300E e55amg seats,xenon lights, twin spoke rims, H&R cup kit, dark tint windows
1987 E300TD slow and steady

So the K40 was the final piece of the puzzle?

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Terry,

Yes, the K-40 was a final piece to a long troublesome puzzle.
You first comments to zip tie every thing was the very last piece.
And everyone should zip tie all of their vacuum and boost lines...Very important.

I just bought something that was way broken and that is why I got a good deal.
I almost gave up on M/B. I did pass on a 1999 E300 TD that only had 70,000 miles and was suppose to have every option including leather seats. But I still have old faithful that runs all the time('87 300d TD).
I now have plenty of diesel tools and test equipment. All I need to buy is a good CD on this 210 version(606.962). I'll have to re look your posts on chipping options.
I am forever indebted to all that helped with words of wisdom and knowledge.

What a wonderful helpful site. Thanks to all again.

Larry12
San Diego
'87 300d Turbodiesel 245,000 with only 50,000 on engine rebuild
'99 E300 Turbodiesel 130,000 and running like a top.. Not as fast as my Pantera but sure a lot quieter and better on fuel.