IP Timing?
 

I recently purchased a 1983 300sd w 258K. It needs a little attention. It is very slugish off the line (below 1500rpm). I have replaced the battery and glow plugs to fix its starting issue. Also I have replaced both fuel filters and adjusted the valves. This helped some. I noticed it has quite a bit of nailing form afew of the cylinders at low rpm. I did a diesel purge and that helped a little. Yesterday I removed the injectors, disassmbled and cleaned them. There was little change. I have also checked the banjo bolt and line. It was slightly dirty but not blocked. I cleaned it -still no change. Lastly I looked at the injecting pump timing. As best as I can determine it is retarded(15 BTDC). I have tried to adjust it with little success. One article I read said to push the pump towards the motor to advance it. The other article said the opposite. Which is correct? Also when pushing towards the motor (I believe this is the correct direction)it seems there isn,t enough adjestment to get to 24 BTDC.This is w/o the lines atached etc. Is it possible the pump was not properly installed to give enough adjustment? It looks like the timing chain is recent( only 1.5 deg stretch) What do you think?

Thanks!

A friend had a similar car with a similar problem. After doing all you have done and more, we concluded the torque converter is the problem.
Other years and models with basically the same engine have a torque converter that lets the engine rev to about 2400 rpm. At 1500 rpm not much is happening in the engine.
Don't mess with the pump unless the chain is very stretched; and if that is the case, replace the chain before attepting to adjust the pump.

Sounds like the pump is okay @ 15°.

Maybe you have a dirty tank screen?

ALDA adjustment?

'83 spill timing is 24btdc.
Retarded timing is chain stretch or never set correctly in the first place.
The 'slow off the line' problem is the ALDA.
Remove the tamperproof case and unscrew the center screw...until it smokes slightly at wot....tighten lock nut when finished.

Spill time the pump....set to close to 23 btdc as possible and disconnect the turbo waste gate hose... and pull the electrical connector off the over boost switch.
Now run a test.:)

Top of i/p towards the engine is advance ...loosen the rear support too and slacken all the line nuts at the head.



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If you cant get to 24 btdc then you are going to have too pull the pump and move it one spline tooth, but I would make darn sure of the timing before doing that. How did you check timing? It could be 15 degrees retarted. A friend bought a 240D that had a long history of not starting well, he discovered the timing was at 6 degrees (cant remember which way) anyway I would make sure of that timing.

If the timing chain is recent, there should not be a problem to get to 24 BTDC and you might have something amiss in your procedure.

To be 9 degrees retarded with a brand new chain is almost impossible unless someone removed and reinstalled the pump improperly in the past.

Take a look for the IP alignment marks. There is a mark on the IP flange and a mark on the block. These marks were supposedly in alignement when the vehicle was shipped from the factory.

The SD has 2.5 degrees of stretch in the chain and it makes it to 24 BTDC, but without much capability of going any further.

One additional point to note: If the IP won't go closer to the engine, but, you can't see where it's hitting the engine up near the top of the IP, then, in all likelihood, you have failed to properly loosen the lower screw that secures the IP. This screw is very difficult to find and even more difficult to move. It must be done from the top with a long box wrench that reaches down between the back of the IP and the oil filter housing.

Many folks have failed to set the IP properly because of the inability to find and properly loosen this lower screw.

Could you explain that logic?

Sure, the pump timing isn't that far off if the chain is not stretched, hence it doesn't need to messed with.

If chain stretch was the only factor affecting injection timing, that theory might have some validity.

What other factor would change the pump timing? Other than someone messing with it, that is.

I am thinking that possibly the chain was replaced recently and that may have thrown the pump off by a tooth? I have loosened everything,lines and the bolt in the back. The one thing that is preventing further rotation is the slot in the pump itself. I am going to push it as close to the engine as possible and check the timing again. Then maybe mess with the ALDA.

Thanks.

I think someone had messed with your injection pump timing and has it set wrong! It sounds to me like the timing is off by one tooth! Do the drip method and see where the pump stops dripping fuel while pumping the primer pump and it should stop at 24* btdc. If it doesn't you will need to turn your engine by hand until the timing marks line up on the front pulley and timing pointer. Stop turning at 24* btdc and check valve timing as well. If pump is still squirting fuel out in larger volumes than a 1 per second drip, your timing is too late! You will have to remove the pump and line up the injection pump marks and re-install it! went through this one myself!:book:

I agree with Knightrider. Drip check the pump timing. But you may be able to rotate the pump into time without removing it. If you do need to remove the pump and reset the timing marks, you will still need to drip time it afterwards to get it exactly right.
Once you get all this back together, check the stall speed (using the tach)of the torque converter by holding the car with the foot brake and accellerating the engine while in gear.

When we bought our 83 300SD it was very sluggish. I found the lever on top of the valve cover that connects to the cable on the transmission to be rotated 180 degrees and not pulling the cable. I believe this cable downshifts the transmission from 2nd to 1st gear when you depress the accelerator. I disconnected the cable, rotated the lever and hooked the cable back up - fixed the problem. The previous owner had complained to the dealer who had installed a rebuilt transmission when they purchased the car. The dealer told them diesels are just slow like that. The PO had been taking off in 2nd gear for three years!!!

IP timing
 

If memory serves me properly , as a test I could get timing advanced up to 28.5 degrees BTDC .....This had the IP pushed all the way to the stop toward the engine...I just did this as a check to see what the entire adjustment range would be....I think the lower timing number was about 17-18 degrees BTDC....I then set it to the correct begining of delivery with drip tube which is 24 degrees BTDC...I was surprised how well the engines would crank and run across the entire 10-11 degree range (stop to stop)....It seemed to be about 25-26 degrees for best overall running.....I did this on my 1980 240D and my 1978 300D and the numbers tracked very closely on both vehicles....If 15 degrees BTDC is as close as you can get fully advanced...It does sound like you are off one tooth.....Like the earlier post says....Best to check crankshaft,valve train timing as a start before pump timing....