Little or NO power after bottoming out suspension- 1981 300SD - Page 2 - PeachParts Mercedes-Benz Forum

GregMN · #16 02-16-2013, 01:20 PM

Disconnect the exhaust from the manifold to test for a restricted exhaust system.

ROLLGUY · #17 02-16-2013, 01:40 PM

Quote:

Originally Posted by GregMN

Disconnect the exhaust from the manifold to test for a restricted exhaust system.

I thought of that when the turbo was off, so I blocked off the oil supply to the turbo and fired it up without any manifolds, nothing changed.

KarTek · #18 02-16-2013, 06:14 PM

Is this an OM603? If so, you can remove the side cover of the pump and run the engine to observe the rack and make sure it's moving in response to the throttle input. Also, try remove the vacuum line from the shutoff actuator to make sure something's not goofing up the vacuum system and causing the shutoff to try to kill the engine all the time.

Check the shut off lever to see that it's in the proper position too.

I've also seen a case where vacuum or blow by (don't remember which) was invading the injection pump and causing the ALDA or shut off to adversely effect the performance of the engine. You can try running the engine with the oil cap off and see of that makes a difference.

ROLLGUY · #19 02-16-2013, 09:02 PM

Quote:

Originally Posted by KarTek

Is this an OM603? If so, you can remove the side cover of the pump and run the engine to observe the rack and make sure it's moving in response to the throttle input. Also, try remove the vacuum line from the shutoff actuator to make sure something's not goofing up the vacuum system and causing the shutoff to try to kill the engine all the time.

Check the shut off lever to see that it's in the proper position too.

I've also seen a case where vacuum or blow by (don't remember which) was invading the injection pump and causing the ALDA or shut off to adversely effect the performance of the engine. You can try running the engine with the oil cap off and see of that makes a difference.

It is a 617. The vac line was off when the recent test was done, so that is not the problem. I will check out the blow by by removing the cap. Thanks, Rich

BillGrissom · #20 02-16-2013, 09:54 PM

Is there a vacuum/boost gage in the car? If not, hook one up temporary. I did that after putting a used engine in my 85 300D. It wouldn't go faster than 10 mph and wouldn't rev much in N. I knew the engine was good because I had run it on the ground and it rev'ed well w/ no blow-by at all. The boost gage showed 20"Hg manifold vacuum, similar to a gas engine w/ throttle closed, suggesting the problem. I pulled the plastic duct off the turbo inlet and found a wad of paper towels I had stuffed to keep things out of the turbo. Ran great after that. Probably not your problem, but easy to try.

ROLLGUY · #21 02-16-2013, 10:12 PM

Quote:

Originally Posted by BillGrissom

Is there a vacuum/boost gage in the car? If not, hook one up temporary. I did that after putting a used engine in my 85 300D. It wouldn't go faster than 10 mph and wouldn't rev much in N. I knew the engine was good because I had run it on the ground and it rev'ed well w/ no blow-by at all. The boost gage showed 20"Hg manifold vacuum, similar to a gas engine w/ throttle closed, suggesting the problem. I pulled the plastic duct off the turbo inlet and found a wad of paper towels I had stuffed to keep things out of the turbo. Ran great after that. Probably not your problem, but easy to try.

Per previous posts, the turbo was rebuilt in between different tries to fix the engine. It had the same symptoms even without the manifolds or turbo installed.

t walgamuth · #22 02-16-2013, 10:58 PM

I don't see how bottoming the suspension could damage the IP.

300dmichael · #23 02-16-2013, 11:10 PM

I would pull the valve cover off and check the mark on the cam to be sure the chain didn't jump a tooth..It is not likely, but if it did, I think it would create the symptoms you are having

barry12345 · #24 02-17-2013, 01:44 AM

A serious jolt may have moved some things around. Make sure the linkage is advancing the arm on the injection pump properly with the pedal. You may have already checked that.

When the oil pan hit the engine was probably deflected back and perhaps upward a little. May have bent a linkage or disturbed it in some other fashion. You want one person on the pedal and yourself watching the arm on the injetion pump hit it's stop.

t walgamuth · #25 02-17-2013, 07:50 AM

On my 74 240d we had a recurring problem of losing power. After pulling the IP four times I took it to a repair shop in Cincinnati that did a lot of mb diesel work.

They finally figured out that the little splined double sleeve that connects the drive on the Ip to the Sprocket on the cam chain was worn so much it allowed the drive to slip a spline. One spline slip would reduce power so you had to floor it to maintain 70 mph, the second spline slip rendered the car unable to exceed 40 mph.

That engine was by far the most worn mb engine I have been into. I think the po must have believed that being a mb it was so durable that it did not need the oil changed ever.

They replaced it with a spline from a sixty something fuel injected gasser mb that they had lying about.

ROLLGUY · #26 02-17-2013, 10:04 AM

Quote:

Originally Posted by t walgamuth

I don't see how bottoming the suspension could damage the IP.

I didn't either, but replaced it anyway. Found out that something else must be wrong (see above posts).

ROLLGUY · #27 02-17-2013, 10:05 AM

Quote:

Originally Posted by 300dmichael

I would pull the valve cover off and check the mark on the cam to be sure the chain didn't jump a tooth..It is not likely, but if it did, I think it would create the symptoms you are having

Been there, done that. I even adjusted the valves while I had the cover off.

ROLLGUY · #28 02-17-2013, 10:09 AM

Quote:

Originally Posted by barry12345

A serious jolt may have moved some things around. Make sure the linkage is advancing the arm on the injection pump properly with the pedal. You may have already checked that.

When the oil pan hit the engine was probably deflected back and perhaps upward a little. May have bent a linkage or disturbed it in some other fashion. You want one person on the pedal and yourself watching the arm on the injetion pump hit it's stop.

The entire throttle linkage works as it is supposed to. I have operated it by hand and checked to see that it actuates the IP correctly.

ROLLGUY · #29 02-17-2013, 10:12 AM

Quote:

Originally Posted by t walgamuth

On my 74 240d we had a recurring problem of losing power. After pulling the IP four times I took it to a repair shop in Cincinnati that did a lot of mb diesel work.

They finally figured out that the little splined double sleeve that connects the drive on the Ip to the Sprocket on the cam chain was worn so much it allowed the drive to slip a spline. One spline slip would reduce power so you had to floor it to maintain 70 mph, the second spline slip rendered the car unable to exceed 40 mph.

That engine was by far the most worn mb engine I have been into. I think the po must have believed that being a mb it was so durable that it did not need the oil changed ever.

They replaced it with a spline from a sixty something fuel injected gasser mb that they had lying about.

The splined collar is perfect in every way. The engine runs exactly the same every time I installed the IP (the third time so far with 2 different IP's)

Dubyagee · #30 02-17-2013, 10:45 AM

Whats the oil pressure through all of this.