Questions involving I.P. timing. - PeachParts Mercedes-Benz Forum

sethza · #1 07-20-2011, 02:20 PM

Hey guys,

1979 240d....
I had a post on here about a rough idle when warm, Ive done almost everything I can do myself with no improvement. I've decided to check the Injection pump timing, but am having a strange problem...

I have the mercedes factory service manual for my engine, and it lays down pretty clearly the procedure for timing the ip. I have the special drip tool and I checked the timing EXACTLY as outlined in the manual. The only problem is, it doesnt start dripping untill about 10 AFTER top dead center! Its supposed to be 24 before. I even pulled the valve cover off to make sure I was on the compression stroke for number one (had both cam lobes up on #uno while lined up with the marks on the crank pulley and the notch on the cam) I had the regulator on the ip set to WOT, as outlined in the manual, as well as removed the spring and that other little piece from the i.p. before putting the tool on.

Am I looking at the marks on my crank pulley correctly? It seems like I should be looking to time it at the marks to the LEFT of the zero mark, because thats 'before' that piston hits the top. The car idles rough, but it doesnt run THAT rough, i'd think 30 degrees off would make it pretty much undriveable. Is there something wrong with the I.P.?

I am officially stumped, and I dont want to muddle with my car any further until I have a little more insight..

P.S. there appears to be NO cam chain stretch. There shouldn't be any need to mess with the pump, but its free and i had the tool. Also the engine sat for a very long time without being run, and i wasnt certain if that would have some effect on the pump.

Thanks a mil

Seth

junqueyardjim · #2 07-20-2011, 02:26 PM

Well Seth, be sure you know what you are doing when messing with that IP. Personally, I will never ever touch mine, but some of the guys will go for it. Anyway, go back to the Factory SM and check it out and verify the cam shaft timing by the way they set it. I have seen it on my CD manual and it is pretty straight forward

tangofox007 · #3 07-20-2011, 02:41 PM

If the timing is that far off, you are going to need to remove and re-index the IP. You won't have enough adjustment range to set the timing correctly.

If I were you, I would remove the IP and re-index it. That way, you can be sure of your starting point in the process. (This assumes that you are 100% sure that you have followed the FSM directions completely.)

sethza · #4 07-20-2011, 03:10 PM

I wish there was a class i could take on JUST this engine...theres no shop in town i'd trust with this, except the dealership and thats 120 bucks an hour.
I've never heard of re-indexing the pump, is there a thread on this website?

What would cause it to be that far off? I'm confident i followed the procedure in the manual. Is there a thread with pictures on this website for checking the IP timing? If not we need to make one, after i figure out how to do it, ha ha. I guess i need to talk with someone whos done this procedure before.. theres no one in town that i know. Any tucsonans out there? If something caused the pump to need to be re-indexed, would i be looking for mechanical failure in the pump? is it possible it slipped on the timing chain, from being started after sitting a long time and being cranked for a little while with probably little oil in the pump? Wouldnt it run alot worse if it where really this far out of time? Could a bad hand pump not be pushing enough pressure through the ip during the procedure?

Thanks again!

Seth

Diesel911 · #5 07-20-2011, 04:47 PM

There might be another possible for you. Fast lane (the pictures are from Fast Lane special Tools for Diesel page 58).

The timing tools in the pictures go into a Plug that you remove from the side of the Governor Housing.

On my 84 I used the one in the left picture. (Note: The timing is done 15 degrees After Top Dead Center.)

You most likely need the one in the right hand picture.

It would be best if you could post a pic of your Fuel Injection Pump so I could see what type of Plug you have on the side of your Governor Housing.

winmutt · #6 07-21-2011, 05:00 PM

Quote:

Originally Posted by Diesel911

There might be another possible for you. Fast lane (the pictures are from Fast Lane special Tools for Diesel page 58).

The timing tools in the pictures go into a Plug that you remove from the side of the Governor Housing.

On my 84 I used the one in the left picture. (Note: The timing is done 15 degrees After Top Dead Center.)

You most likely need the one in the right hand picture.

It would be best if you could post a pic of your Fuel Injection Pump so I could see what type of Plug you have on the side of your Governor Housing.

RIV port is only avail on 84 and up MW pumps.

To the OP, there is a bit in the FSM that SOME pumps are offset by 3 teeth due to a problem from the bosch factory.

Diesel911 · #7 07-21-2011, 07:27 PM

Quote:

Originally Posted by winmutt

RIV port is only avail on 84 and up MW pumps.

To the OP, there is a bit in the FSM that SOME pumps are offset by 3 teeth due to a problem from the bosch factory.

But, there is a Timing/Locking pin that fits some of the Older Pumps with the smaller Plug on the side of the Governor Housing.

I have not read instructions on how to use it but I bet it is the same 15 degrees ATDC after the Compression stroke just like the later models. That is the same timing degrees that the RIV,AB light references to.

If he happend to have one of the IPs that needed the 3 tooth offset it would still flow time at the normal range of degrees.

jt20 · #8 07-21-2011, 10:18 PM

Quote:

Originally Posted by Diesel911

But, there is a Timing/Locking pin that fits some of the Older Pumps with the smaller Plug on the side of the Governor Housing.

I have not read instructions on how to use it but I bet it is the same 15 degrees ATDC after the Compression stroke just like the later models. That is the same timing degrees that the RIV,AB light references to.

If he happend to have one of the IPs that needed the 3 tooth offset it would still flow time at the normal range of degrees.

This is true. But the use of that port is very inaccurate do to chain wear etc.

That does not mean one should not use it. Good call.

Diesel911 · #9 07-21-2011, 11:18 PM

Quote:

Originally Posted by jt20

This is true. But the use of that port is very inaccurate do to chain wear etc.

That does not mean one should not use it. Good call.

I am OK with the Drip Method.

But, if you are unable to do the Drip Method and you need to get you Car on the Road; and, one of the Timing Pins will work on your IP a person could use that a get the job done.

While using the Timing Pin does not compensate for wear inside of the Fuel Injection Pump it does compensate for Timing Chain/Gear stretch/wear.

tangofox007 · #10 07-21-2011, 07:52 PM

Quote:

Originally Posted by winmutt

To the OP, there is a bit in the FSM that SOME pumps are offset by 3 teeth due to a problem from the bosch factory.

The FSM? Is the FSM you are referencing applicable to a '79 240D?

winmutt · #11 07-21-2011, 09:32 PM

Quote:

Originally Posted by tangofox007

The FSM? Is the FSM you are referencing applicable to a '79 240D?

Im referring to the W123 manual. I dont think the teeth being off applies here just a sugg.

Stevo · #12 07-22-2011, 10:29 AM

Quote:

Originally Posted by winmutt

To the OP, there is a bit in the FSM that SOME pumps are offset by 3 teeth due to a problem from the bosch factory.

Here is a quote from an old post I have concerning the problem you are refurring to.

"It turns out that a number of IPs made in 1982 were mismarked, so that you actually have to set the driven element so that the wide mark is 3 splines PAST the timing mark. If you've done this, the pump works like any other. This information is clearly set forth in the OM617 engine manual, proving yet again that, even if you know how to do a job, RTFM first."

tangofox007 · #13 07-22-2011, 10:38 AM

Quote:

Originally Posted by Stevo

Here is a quote from an old post I have concerning the problem you are refurring to.

"It turns out that a number of IPs made in 1982 were mismarked, so that you actually have to set the driven element so that the wide mark is 3 splines PAST the timing mark. If you've done this, the pump works like any other. This information is clearly set forth in the OM617 engine manual, proving yet again that, even if you know how to do a job, RTFM first."

Just make sure the manual that you are reading fits the car that you are working on. It's highly unlikely that an OM616 in a '79 240D is going to be fitted with an OM617 IP manufactured in 1982.

Stevo · #14 07-22-2011, 01:55 PM

Quote:

Originally Posted by tangofox007

Just make sure the manual that you are reading fits the car that you are working on. It's highly unlikely that an OM616 in a '79 240D is going to be fitted with an OM617 IP manufactured in 1982.

Good of you to point that out

winmutt · #15 07-22-2011, 11:01 AM

Quote:

Originally Posted by Stevo

Here is a quote from an old post I have concerning the problem you are refurring to.

"It turns out that a number of IPs made in 1982 were mismarked, so that you actually have to set the driven element so that the wide mark is 3 splines PAST the timing mark. If you've done this, the pump works like any other. This information is clearly set forth in the OM617 engine manual, proving yet again that, even if you know how to do a job, RTFM first."

Ah limited to 1982.