Bizarre symptoms E300TD update
 

After implementing many of the suggestions offered here, I was able to get
my 99E300TD back on the road. Replacement of the O-rings and the pre filter
and main filter got all the air bubbles out of the system. While in the shop,
a bad alternator was found to be the cause of both the "battery charge" warning that came on intermittently and rapid wear on the belt tensioner shock. All was great EXCEPT now the car misses periodically at idle only in neutral or park. Shift to D or R and it idles normally. Accelleration and cruise
is normal as is fuel consumption. Now the car is in a different shop in a different city for the third day while a further diagnosis is being attempted.
This shop thinks it is an electrical problem since it idles normally when the lights are turned on or when the Compressor is engaged. I suggested that this simply is putting load on the drive belt much as shifting into gear is especially since no electrical problems have popped up. Injectors have been ruled out as have the ECM and the injector pump(how, I don't know).

Anyone got an idea?

Steve

check the belt tensioner damper, chances are it has something do with your drive belts, or auxillary belts

Check your motor mounts and engine shocks, if it has them.

New belt, tensioner, new engine mounts, everything works on the car, ran diesel purge. interestingly, the car idles normally when it is cold and starts missing once it warms to operating temp.

Steve

I would think about what changes occur when the car warms up.

Glow plug timer ends, fuel thermostat loop is closed(?), coolant thermo opens, fuel/air mix changes and a few zillion other things.

Have you tried cold start with AC control panel OFF to see if miss is present when cold?

yes it is bizarre, check this link,
 

The shop here in Santa Fe had the car for three days and was unable to find anything that might cause the missing at idle, given that we had already replaced all the filters, o-rings, tensioner shock, s- belt, cleaned egr, new manifold gasket, etc. There are no fuel leaks, fuel is clean and fresh, all systems work, good voltage, no smoking of any kind, fuel mileage and accelleration are normal.

The verdict: software problem in ECM causing shaking during decelleration and at idle.
damage code 54 581 90
remedy according to damage code or diagnosis manual
part # 025 545 55 32 engine control module

The good part is the shop only charged me a nominal diagnosis fee and the ECM is "only" $700 or so.
Has anyone had a new ECM installed for any reason and did it cure the suspected problem, or will this be another part thrown at the car?

Thanks to all who read and reply

Steve

BTW----paid $2.38 for diesel in Albuquerque at 4th st. Phillips 66 yesterday

Question. What do they say? Do they gaurantee that this will fix it? IOW, if it doesn't, what happens to your $700 ECM?

Can't they reflash the ECM, i recall someone posted a TSB about this problem before on here I will try to find the link