Why the heck does my '92 300D sputter and run rough at 14 deg ATDC but when I change the timing to 9 deg ATDC it runs fine. Anything above 9 deg's and it starts sputtering and puffing white smoke.

BTW - I recently changed all Injectors to Monark's...

Confused....

How far off TDC is the crank pulley when the cam is at TDC?

Sixto
87 300D

Sixto,

Do I do this by opening the oil fill and turn the engine until the cam lob is straight up?

Thanks.

You need more precision. Pull the valve cover so you can see the cam sprocket. Align the notch on the cam sprocket flange with the ridge on the cam bearing tower -



This picture makes it clear what you should accomplish but in practice I find it easier to sight the cam tower ridge down the sprocket flange notch looking through the sprocket. Read the crank pulley timing marks when the cam marks are aligned. The cam marks align every two crank revolutions. Take at least six readings then take the average of the readings.

The FSM method is to set a dial gauge on the #1 intake lobe which you're welcome to try if you have the equipment.

Sixto
87 300D

Thanks Sixto - I'll give this a shot.

If there is a discrepancy between the two - what would cause this?

-John

Chain wear. IIRC more than 3* elongation is indication you need a new chain. There's a TSB about early 2.5s experiencing premature wear of the cam sprocket. I don't know if this translates to accelerated chain wear.

Sixto
87 300D

Is this one of those engines where if you remove some of the Components you need to remove the Pointer?
If that is so someone could have change something and forgot to mark the Pointer position before removing the Pointer.

__________________
84 300D, 82 Volvo 244Gl Diesel

Pop pressure will effect timing. Did you put the injectors on a pop tester and see what the opening pressure is?

__________________
1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

Sure did. Pop tested each injector and all pop'd around 1995-2000 PSI.

Which I think is on the high side - yes?

-John

Diesel911 - not sure if the pointer needs to be removed in order to get to other components. Maybe someone else will comment.

There is evidence that the transmission was removed at one point - but I don't have maintenance records for this car.

I plan on pulling the top and check for chain stretch today.

I pulled the top and measured as Sixto mentioned. When the top reads TDC the crank shows 3 deg.

-John

Didn't run well (sputtered/smoke) at 17 deg - I was able to get the car to run well near 12 deg.

Is this due to the Monark injectors that pop at 1990-2000 PSI?

-John

Runs well at idle - but stutters on acceleration during the test drive.

Looks like I'm going to have to pull it apart and time the IP again.

I thought the chain might be way out of spec but 3* is about the wear limit and other 603s with 3* of elongation have no issues with the IP timed to spec. I don't know what retiming the IP will accomplish.

Sixto
87 300D

Sixto/All,

Really need your brain power on this one. I'm really stuck.

A quick bit of history to maybe help:

a) IP was replaced a few thousand miles ago and I timed the engine to 14-15 deg ATDC. Car ran well except for turbo/fuel issue (another story)
b) Replaced the injectors with Monark's last weekend after pop testing them. All pop at 1990-2000 PSI.
c) After new injectors the engine was MUCH louder at idle - no mis-fires - just loud nailing (assuming the IP timing was at 14-15 but I didn't verify)

Thinking the nailing was due to timing issue with the new injectors (diff pop pressure from the old injectors/etc) - I found the following timing results (chain stretch is about 3 deg):

1) At 17.5 deg (14.5+3) = Heavy stuttering/white smoke. Engine would stall.
2) At 14.5 deg = Bad stuttering/white smoke
3) At 12 deg = No stuttering - some white smoke. Engine idles well but during test drive nails badly during acceleration and has no power
4) At 9 deg = No stuttering - very little white smoke. Engine idles well but heavy nailing during acceleration and very little power.

I'm at a loss. I thinking making a bad head gasket? But why am I having this issue now after the new injectors?

Any help great appreciated. I'm really at a loss at this point.

-John