Help! I'm throughly confused about pump timing.

[RLDSL]

This is my first Diesel powered pickup. I know about older cars with Carbs and Distributers. What I was tought was to add 2 degrees of ignition timing for every 1000 gain in Elevation.

So if a car was spek'd for say 0TDC @ sea level we would run the timing up to 6BTDC @my 3000ft elevation to get performance back.

Are you saying that with a diesel you retard the injection timing as you go up in elevation?

EEK SCREECH NOOO that is completely bass akwards ! As you go UP in elevation, you INCREASE the advance in injection timing and REDUCE the injected amount of fuel to lean out the mix to compensate for the reduced amount of air. You begin making adjustments at around 3800 ft and in intervals therof so if the vehicle is going to be spending most of its time around 3800 you set for that, if 7600 ft you set for that, if you live in the bolivian high country up around 11-12000 ft, you have all kinds of fun trying to adjust things to make it run ( I know some fellas with some European diesels who live there that have fun keeping engines happy at that altitude ) Why the stanadyne pumps didnt come with automatic altitude compensators on them I have no idea. Bosch started putting them on car diesels in the early 80s to where they had a little altitude sensor that would automatically increase the injection timing and reduce the injected fuel amount when you got above 3800 ft, and if you normally started at a higher altitude you could get an anaeroid ( seperate from the anaroid on the pump, this one would be mounted externally ) that sensed higher altitude points for it to change over at

Are you certain that, !) you are using teh correct spot on the timing tab to time from. 2) that your harmonic balancer has not separated from the rubber elastomer isolation dampener strip and has rotated ( fairly common ) ..3) you are attached to the correct injection line either #1 or 4 1 is the first one on the left if facing the engine from the front and four is the second back on the right, because quite frankly, it should barely be running at 5 deg on the new fuel.
The only thing I could think that might make it run worse when properly timed is someone may have cranked the fuel screw all teh way up in an attempt to compensate for the lousy timing and them with that much excess fuel , with it set properly it would be so overfueled it would run like hell or possibly the cold advance solenoid isw stucking on

 

[Black dawg]

I did not know that the advance can be adjusted externally. can you explain more ?

you can adjust the cam on the throttle shaft to change timing

 

[chris142]

I read this thread that talks about the 0 on the tab and the mark on the balancer.

http://www.oilburners.net/forums/showthread.php?60267-TIMING-MARKS-FOR-TIMING-LIGHTS-Tech-101

So I'm doing it right. I guess that the balancer could be slipped but w/o removing it and comparing it to a known good one I won't be able to tell. Normally when the balancer goes bad it spits some rubber out the sides. Mine has not so again I'm going to ASSUME that it's ok.

But anythings possible on a 25 yr old truck.

 

[riotwarrior]

I read this thread that talks about the 0 on the tab and the mark on the balancer.

http://www.oilburners.net/forums/showthread.php?60267-TIMING-MARKS-FOR-TIMING-LIGHTS-Tech-101

So I'm doing it right. I guess that the balancer could be slipped but w/o removing it and comparing it to a known good one I won't be able to tell. Normally when the balancer goes bad it spits some rubber out the sides. Mine has not so again I'm going to ASSUME that it's ok.

But anythings possible on a 25 yr old truck.

I still think your issue is a pump re n re the incorrect method by removing the IP PUMP and the TIMING gear cover as a package...instead of removing the IP from the timing gear cover and leaving the cover attached to the engine.

By removing the IP gear cover...you can very easily replace the gear and cover off a tooth or two or more...this would equate to a situation such as you are currently in with the IP moved all the way to one side.

The other issue is you could possibly be using a questionable timing light. One way to know for sure...test it on a gasser...set initial timing at lets say 10 degrees with no advance dialed into you light. Then set your light to 9 or 9.5 and run that gasser engine and test again. now the light should theoretically show the timing as 1/2 or 1 degree BTDC and if it does. your lights goldent if it doesnt...well thats not a good thing...recheck and recheck...or dial advance in till you can get it back to 1/2 or 1 degree and see how far out it is....

JM2CW but could be worth the effort.