Status update Timing has been corrected, didn't help.
Turbo boost restored to ~14 psi, and that helped to resolve a lot of the problem. Smoke is gone, but the nailing persists. Correct glow plugs installed, didn't help. Injectors with new Monark nozzles installed tonight, and if anything the problem is worse. :\ I may need to find a new mechanic. The fellow who installed the injectors FAILED to put heat shields under #1 and #2!!! What a looser! When I found this I thought "Ahh HAH!! This is it!" but alas I don't see the improvement I was expecting. Perhaps there is excessive carbon build up in those two pre-chambers, and I've got to burn that out? I can think of three more things to try: (1) Rebuild the delivery valves (DVs) again. (2) Swap all the DVs with a "known good" used set, from the original pump. (3) Replace the injection pump. I don't think compression is the issue, the car started just fine at 28 deg F this a.m., and per normal it idles smoothly for a few seconds while the glow plugs are hot, and then it starts to miss. -Max >On Jan 15, 2017 10:10 AM, "Meade Dillon via Mercedes" ><mercedes@okiebenz.com> >wrote: > >Dieselvolk, > >Here's the situation: My 124.193, with 365k miles, isn't running well >at >all. Under anything more than gentle throttle, the engine pings and >smokes. Mileage is bad, around 22 mpg in town, about 25 on the >highway. I >used to get about 26 in town, 28 on the highway. Starts fine, idles >fine. >A diesel-purge treatment will clear it right up, and it will run just >fine >(and get better mileage) for about a month, and then it declines back >to >poor running. Italian tune-ups will also help a bit (especially with >the >smoking). > >What changed? I installed an injection pump from a 3.5 liter engine. >One >of the three hold-down tangs on the original IP broke (long story) so I >had >to replace it, and I had this 3.5 liter IP on the shelf. > >When I installed this "new" IP, I overhauled the delivery valves, and >adjusted the ALDA 1/2 turn richer. I have since moved the ALDA screw >back >to the original position, I think, I need to check the records. I may >have >only moved it back 1/4 turn. > >What else is wrong? I have the wrong glow plugs installed. When I >installed the "new" head a few years ago (with oblique injection) I >swapped >in the relatively new glow plugs from the original head. Oblique >injection >heads use a glow plug that is shorter. > >Last weekend I adjusted the timing (it was a couple degrees advanced), >and >then went on a 900 mile highway trip for work. No change in >performance. >I think that this bigger pump is over-fueling the engine, resulting in >lots >of un-burned fuel and carbon build up. > >Options that I can think of: > >1) Back off the ALDA screw a little more. >2) Install the correct glow plugs. >3) Check the turbo output, bump it back up if low. >4) Remove the 3.5 liter injection pump, put a 3.0 liter IP back in >(Wilton's old 300D engine has one) >5) Pull the engine and tranny, swap in engine / tranny from Wilton's >300D. >This is attractive because my engine has a nagging oil leak that I >haven't >been able to solve, plus that engine / tranny are much younger, only >143k >miles. The downside is that engine still has the original #14 head, >but >that is minor (I think the head is sound). > >------------- >Max >Charleston SC _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
