Engine loose power - PeachParts Mercedes-Benz Forum

nyko46 · #1 05-06-2006, 11:22 PM

On my 1984 MB - 300 SD with 215k miles, the car is too slow to take of but on highways it ran fast.When in a up hill the car loose speed even presssing the acelerator to try to get more speed.Tranny is in good shape,engine has valves recently adjusted,on line and main diesel filter are new.Fuel injectors was tested showing good.There are not smoke from burning oil and the mileage per galon are good.Brake pads and parking brake are ok.
I still wondering what can be the reason for this incovinient.
Can you share something about it?
Appreciate.
Thanks.
Nyck:

tangofox007 · #2 05-06-2006, 11:34 PM

Clean the plastic line that attaches to the rear of the intake manifold.

nyko46 · #3 05-06-2006, 11:42 PM

Quote:

Originally Posted by tangofox007

Clean the plastic line that attaches to the rear of the intake manifold.

It was done and the connections on manifold was dirty and clogged.
I clean it and the full lenght of the hose with carburator cleaner.
Made no difference.
If some another ideia I will be glad.
Thanks for your tip.

tangofox007 · #4 05-06-2006, 11:46 PM

Have you checked the compression and injection pump timing? Also, adjusting the ALDA might be helpful.

nyko46 · #5 05-06-2006, 11:56 PM

Quote:

Originally Posted by tangofox007

Have you checked the compression and injection pump timing? Also, adjusting the ALDA might be helpful.

I did not check compression and pump time seems to be ok.
I never heard about adjust ALDA.
It is that component on top of the injection pump where a vaccum hose is connected. As I know, ALDA is for compensation of the altitude.
Am I right?

tangofox007 · #6 05-07-2006, 10:13 AM

Quote:

Originally Posted by nyko46

It is that component on top of the injection pump where a vaccum hose is connected. As I know, ALDA is for compensation of the altitude.
Am I right?

That's correct, except that the hose is for pressure, not vacuum.

There is an adjustment screw in the center of the ALDA capsule. If you cannot see a screw there with a locknut, then you likely still have a seal attached. If so, cut the aluminum/plastic seal off and discard.

Loosen the locknut and turn the screw slightly counterclockwise, then test drive the car. Repeat as necessary. Make small adjustments. (Do not force the screw if you reach the limits of its travel.) There is a spring in the ALDA which looses tension with age. Initial acceleration performance will be negatively affected. It is possible that the ALDA adjustment will make a vast improvement in initial acceleration.

nyko46 · #7 05-11-2006, 06:48 PM

Quote:

Originally Posted by tangofox007

That's correct, except that the hose is for pressure, not vacuum.

There is an adjustment screw in the center of the ALDA capsule. If you cannot see a screw there with a locknut, then you likely still have a seal attached. If so, cut the aluminum/plastic seal off and discard.

Loosen the locknut and turn the screw slightly counterclockwise, then test drive the car. Repeat as necessary. Make small adjustments. (Do not force the screw if you reach the limits of its travel.) There is a spring in the ALDA which looses tension with age. Initial acceleration performance will be negatively affected. It is possible that the ALDA adjustment will make a vast improvement in initial acceleration.

I was looking on the top of pump and there are a plastic part where the hose is connected and no screw found. I saw a screw and counternut at the back cover of the pump near the vacuum shut off valve.
Are you talking about that screw?
Thanks.

RAYMOND485 · #8 05-11-2006, 08:13 PM

1984 300d Turbo 138k
Remove The Pressure Line From Alda Relay On Firewall And Use The Pressure Top Of Hand Vacuum Pump And Pressure Fuel Gage To 10 Psi Pump Up 10 Psi To Alda Check If Leaks, Remove Alda And Small Rubber O-ring Leaks Replace From A Metic O Ring Kit Mercedessoure.com Or Jcwhitney.com You May Have To Drill Out 4 Screws And Big Nut Under Alda Ccw 1 Hr Diy, Check The Rear Maniford Bolt Remove And Clean, Go To Pindelski.com Yearly Fee For Instuctions

Motorhead · #9 05-11-2006, 08:22 PM

Check to see if you are getting full throttle. Have someone depress the gas pedal to the floor and see if the pump is at the full speed stop on the engine side of the inj pump. I agree on adjusting the ALDA... it wakes up older inj pumps. BEFORE you go further, (I read that you cleaned out the line at the intake), take the boost line loose from the ALDA unit and make sure it is open through the over-boost bleed off. I had an '84 diesel wagon that had the over-boost valve plugged. The car was a real slug on take off. GOOD LUCK

nyko46 · #10 05-16-2006, 10:27 PM

Quote:

Originally Posted by RAYMOND485

1984 300d Turbo 138k
Remove The Pressure Line From Alda Relay On Firewall And Use The Pressure Top Of Hand Vacuum Pump And Pressure Fuel Gage To 10 Psi Pump Up 10 Psi To Alda Check If Leaks, Remove Alda And Small Rubber O-ring Leaks Replace From A Metic O Ring Kit Mercedessoure.com Or Jcwhitney.com You May Have To Drill Out 4 Screws And Big Nut Under Alda Ccw 1 Hr Diy, Check The Rear Maniford Bolt Remove And Clean, Go To Pindelski.com Yearly Fee For Instuctions

This is a good idea.Checking ALDA using pressure will tel me if there are leaks and also if ALDA is in good condition.
From where come pressure to ALDA?
Don't you think also in a chance of the ALDA relay not be working?

nyko46 · #11 05-16-2006, 10:33 PM

Quote:

Originally Posted by Motorhead

Check to see if you are getting full throttle. Have someone depress the gas pedal to the floor and see if the pump is at the full speed stop on the engine side of the inj pump. I agree on adjusting the ALDA... it wakes up older inj pumps. BEFORE you go further, (I read that you cleaned out the line at the intake), take the boost line loose from the ALDA unit and make sure it is open through the over-boost bleed off. I had an '84 diesel wagon that had the over-boost valve plugged. The car was a real slug on take off. GOOD LUCK

When driving the car and felling it so slow, I did for many times press acelerator to maximum.The RPM rises but not the torque of the car.
I liked also your idea of the chance of boost line plugged.Is one more item to be checked.
Thanks.

nyko46 · #12 05-16-2006, 10:39 PM

Quote:

Originally Posted by nyko46

I was looking on the top of pump and there are a plastic part where the hose is connected and no screw found. I saw a screw and counternut at the back cover of the pump near the vacuum shut off valve.
Are you talking about that screw?
Thanks.

Thanks for your tip.
I found the counternut and screw that you talk about.
I will have a change at the end of this week to follow your procedures.
If you have some another idea I will be happy in learn some more.
Thanks.