i have no torque in my 83 300d, i wanna change it - PeachParts Mercedes-Benz Forum

kbenjamin0106 · #1 07-02-2009, 11:16 AM

i have a 83 300d turbo diesel, original owner since 1983 and this thing has nearly no torque at all when i punch it, i had a 85 300d with amazing torque and it would attack almost 90 degree hills. it had 165,000 miles.

to make things short i want my 83 to have that torque. the motor and tranny has 138,000 miles still on the original injectors. it has 10 pounds of boost but i hardly feel it or hear the turbo, it has no turbine play or anything, i did clean the banjo bolt, fuel filters replaced, the alda is still a virgin and has never been touched either

haha.

Could my transmission have a role in this problem? my 85 produced enough torque it did burnouts. my 83 wont get the tires to spin in the snow.... right now the 83 shoots a light coating black smoke when pushed hard driving on the road. could my exhaust be clogged since its still original too?

Thanks alot i would really like to get my car fast as it use to be.

vstech · #2 07-02-2009, 11:26 AM

this sounds like a plugged banjo bolt or loose throttle linkage.
I know you cleaned the bolt, but did you clean the overboost relay? did you flush the lines all the way to the alda? have you verified that the throttle linkage goes all the way to the stop on the IP?

pselaphid · #3 07-02-2009, 11:27 AM

Attacking a hill of that slope is inadvisable. The hill will always win and the front of the car will be damaged. Lots of things can account for what you are describing. Start by adjusting the valves and taking care of all other basic maintenence items. Check your EGR valve and maybe fix or eliminate it. You might even just have a different rear differential ratio, in which case you'll have to probably live with the slow takeoff. Torque is not the only thing to consider and you haven't really indicated whether the car runs good at high speed. More specifics about the condition of the car are needed.

toomany MBZ · #4 07-02-2009, 11:28 AM

If all things check out clean, adjust the ALDA.

pawoSD · #5 07-02-2009, 11:42 AM

Yep, adjust the ALDA....sounds like it has gradually gone out of spec. My car can throw me back in the seat on takeoff I have so much torque...all because I adjusted my ALDA to the MAX.

kbenjamin0106 · #6 07-02-2009, 12:31 PM

Quote:

Originally Posted by pawoSD

Yep, adjust the ALDA....sounds like it has gradually gone out of spec. My car can throw me back in the seat on takeoff I have so much torque...all because I adjusted my ALDA to the MAX.

Pawo and others, this is the power i need, whats the safest way to adjust the alda and and how would i be able to clean the switch over valve for the banjo line, just wd 40?? i know it still works cause it clicks when i put my air pump to it and see if it still worked.

for the past decades

ive owned the car i used to use a good bit of kerosene in it and diesel mixed. could this have affected something in my motor? but i havent use kerosene in the car for about 8 years.

my plan is to do a diesel purge with this stuff called diesel kleen, replace the fuel filters again, new injectors, new glow plugs, aftermarket air intake and ill leave the valve adjustments for last if i dont get any more power.

but no one has answered my exhaust question, the black smoke when i punch it, and if i need my exhaust replaced cause its restricting power.

tbomachines · #7 07-02-2009, 12:51 PM

Performance Upgrades...The big Questions
Tweaking ALDA...
alda turned up all the way vs alda taken off
Banjo bolt cleaned today, need input
Switchover Valve Cleaned! Presto!!

I clear the line with brake cleaner, pretty much anything to make sure it is clear will work, WD-40 should be no problem. Diesel Kleen should work okay for a purge, but I would recommend sea foam engine treatment-- same stuff as Lubro-Moly diesel purge (get this if you can). Make sure you don't have a plugged strainer in the tank, clear filters, etc. You might also want to pay attention to any air bubbles in the fuel filter, any sort of leaks coming from the fuel lines. They tend to get old, brittle and swollen. The valve adjustment is probably the most important of the things you listed, and part of routine maintenance for these engines. Forget the aftermarket intake, the stock cold air intake is sufficient, functional, and aruably better than aftermarket intakes like K&N. Black smoke could be soot from the exhaust, could be unburnt diesel fuel (dirty injectors?). Do the valves and diesel purge and see if this gets any better...can I guess that you have injector nailing too? If so - dirty injectors.

#8 07-02-2009, 01:23 PM

The stock exhaust on these cars is pretty free flowing. The biggest restriction in your exhaust system is the turbo itself. You can add a straight pipe for better sound but don't expect any hp gains. Also the black smoke could as other have stated be an ALDA problem or might be injectors or valve adjustment. Also your idea for an aftermarket intake, unless you are upgrading your turbo, might be a waste of money the stock system flows all the air you will need and if setup like the factory is true cold air. But your dime and all have fun and good luck.

pawoSD · #9 07-02-2009, 01:25 PM

Quote:

Originally Posted by kbenjamin0106

Pawo and others, this is the power i need, whats the safest way to adjust the alda and and how would i be able to clean the switch over valve for the banjo line, just wd 40?? i know it still works cause it clicks when i put my air pump to it and see if it still worked.

for the past decades

ive owned the car i used to use a good bit of kerosene in it and diesel mixed. could this have affected something in my motor? but i havent use kerosene in the car for about 8 years.

my plan is to do a diesel purge with this stuff called diesel kleen, replace the fuel filters again, new injectors, new glow plugs, aftermarket air intake and ill leave the valve adjustments for last if i dont get any more power.

but no one has answered my exhaust question, the black smoke when i punch it, and if i need my exhaust replaced cause its restricting power.

Why have you been running kerosene mixed with diesel?

That makes no sense and is completely unnecessary.

tbomachines · #10 07-02-2009, 01:41 PM

Quote:

Originally Posted by pawoSD

Why have you been running kerosene mixed with diesel?

That makes no sense and is completely unnecessary.

I know people do this in cold climates to thin out the fuel and prevent it from gelling up (boosting cetane level? I don't know too much about it). You don't really have to do it anymore since the diesel has been processed in a manner that is mroe tolerable to cold temperatures.

According to this thread:
Modern Diesel Fuels:
it helps prevent gelling. Apparently I was wrong about raising cetane though? I have heard of people adding kerosene to diesel for a long time.

toomany MBZ · #11 07-02-2009, 03:27 PM

Quote:

Originally Posted by pawoSD

Why have you been running kerosene mixed with diesel?

That makes no sense and is completely unnecessary.

The owners manual will suggest using a mixture in very cold weather, yet as mentioned many cold clime areas have winter diesel. I understand the Diesel Kleen for anti gelling may have a cetane boost.too.
http://www.powerservice.com/dfs/
They do make a product that does not have a boost, but I haven't seen any in the stores.
I use the stuff in the silver jug.

pawoSD · #12 07-02-2009, 04:33 PM

The owners manual was written 30 years ago....modern #2 diesel doesn't gel until like -20F....I've started my car as low as -12F with no issues.....and nothing blended with the fuel.

toomany MBZ · #13 07-02-2009, 08:00 PM

Yeah, at the time that may have been the way to go.
I don't go by the tire pressures on the fuel door either.

MTUpower · #14 07-02-2009, 08:31 PM

You'll find that different 617's perform differently. You may never find the set of things to do in order to make this engine as "torquey" as your other one. Get everything up to spec as best as you can. Actually removing some of the restrictions in the exhaust does give you more HP- and sooner. Keep after the small stuff, read up in the diesel performance section and eventually you will be happier with your car's engine.

Skippy · #15 07-02-2009, 11:46 PM

Injectors usually last longer than 138,000 miles, but with substantial kerosene use I could imagine them being prematurely worn out. Unfortunately, I could say the same for the injector pump. If the car is making ten psi of boost, the turbo and related controls are working more or less normally. If it's blowing black smoke, that points to it getting plenty of fuel. However, if the injectors are popping off at too low of a pressure or have a lousy spray pattern, that would produce poor combustion efficiency and the observed phenomenon of low power with accompanying smoke. I would suggest pulling the injectors and having them tested at a shop. Some shops will even do this for free.

The valve adjustment is a regular maintenance item and should be done if it has been over 15,000 miles since the last adjustment.

The only other things that come to mind are EGR stuck open and late injection timing. The EGR can be eliminated and there's really no reason to retain it unless you have stringent emissions inspections to deal with. Injection timing shouldn't have changed in the stated mileage, but I suppose it's possible the timing chain could have somehow jumped a tooth at some point.