85 300d...not so fast

[littlehandegan]

Cleaned my banjo fitting today (Was gunked up), changed fuel filters, air filter and changed oil. Was hoping this would fix my less than impressive acceleration.

Car shows no sign of blow by, is very smooth, with no smoke and has tons of records.

Anything else I should look at?

I had another 85 300d and it was much quicker.
This cars turbo also makes a funny noise at a certain RPM when coming off boost, almost like a kazoo

I am having it taken in to have a valve adjustment (Not sure if it needs it, but previous owner said he dint think it had been done in 15,000 or so), and to have them check the ALDA (Original black cap is on it, maybe it needs adjusting?)

[Mölyapina]

Originally Posted by littlehandegan

Cleaned my banjo fitting today (Was gunked up), changed fuel filters, air filter and changed oil. Was hoping this would fix my less than impressive acceleration.

Car shows no sign of blow by, is very smooth, with no smoke and has tons of records.

Anything else I should look at?

I had another 85 300d and it was much quicker.
This cars turbo also makes a funny noise at a certain RPM when coming off boost, almost like a kazoo

I am having it taken in to have a valve adjustment (Not sure if it needs it, but previous owner said he dint think it had been done in 15,000 or so), and to have them check the ALDA (Original black cap is on it, maybe it needs adjusting?)

Clean the in-tank fuel filter, fuel tank, and fuel lines.

[tomee]

Break the virgin black cap, turn adjusting screw in a few turns, and step back. That car will outrun it's own shadow.

[newtodiesel]

Sounds like you have an air leak at the "U" tube connected to the turbo. Mine made this sound at approx 2,000RPM when it started to spool. After changing this $2 ?? Seal the noise stopped. i kinda got used to it and missed it when it was gone, but know its not proper MB engineered sound.

Maybe follow the lines from the banjo fitting...are you talking about the one in the back of the exhaust? If not clean that one too, just be very careful cranking and twisting on any 20 something yr old lines and fittings as they are age stressed already and can and will break easily, patience is really your friend on these old cars. Follow the lines from the exhaust side over to the drivers side fire wall into the switchover valve and make sure all those lines are clear too, that will lead into the ALDA fitting near the IP.

I will let the others chime in about accerleration as I can use a few tips here too. Some might want you to mess w/ the ALDA a bit and see if you can get some boost..but dont do this unless you know your car is in top condition first...just my 2cents :p.

[littlehandegan]

ALSO!

When I unscrewed the ALDA banjo, I did not see any washers that I kept hearing about. Is it possible that they were not there, or stuck on and didnt move?

[Skippy]

Buy the wrenches and do the valve adjustment yourself. It's pretty easy, just time consuming the first time you do it.

Other things to look at:

Have a helper floor the accelerator while you check at the injector pump to make sure you're getting full travel on the lever at the IP.

Temporarily install a boost gauge to make sure you're getting full boost. I believe the wastegate is supposed to open at 12 psi, but with age they can get out of adjustment. Also, since you have an '85 you may have (not sure if 50 state or just CA) a silly device that cuts boost to facilitate EGR operation. It's not necessary and should be removed or disabled along with the EGR valve itself.

Check timing and timing chain elongation. As the chain wears, it causes timing to be retarded. This can affect performance.

[barry12345]

You found the banjo on the manifold closed off with gunk. If no change after cleaning you may still have an obstruction. There should be pressure at the end of the tube that hooks up to the ada or that system is still comprimised. When you rev up the engine and the blower is pushing air. It should be apearing at the alda feed.