eratic engine miss/low power

Have you replaced the check valve in the filter head? It will cause a miss usually heard for moments after start up.

Probably wouldn't cause low power though unless it wasn't allowing the system to build enough fuel pressure if that was the case it would probably be quite difficult to start.

 

if it smokes when it misses then it sounds alot like the check valve.

 

Was he blind? How could he miss the lobe being gone while R&R'ing the injectors? Are they going to make it "right" with you? I certainly hope so...

 

I have been having just about the same problem. I have already put an injector and new head in it. They keep checking things and say it looks good. I wish someone would say this will fix the problem but no one knows what the problem is.. I hope you can figure it out soon.

 

I've kept quiet about your problem for a reason. Its to hard to diagnose these types of problems on the Internet. But you still have another problem. The injector lobe being wiped out will not cause the jake brake to quit working. I was going to suggest a wiring harness issue when both the jake and the miss were occurring, but now that you've found a bad injector lobe on the camshaft.......you still have a problem with the jake. My thoughts on this are you have the upgraded bolts to hold the jake assemblies down, they could have installed the bolts in the wrong location to hold the jake brake housings to the rocker shafts. By doing this they starved the jake brake for oil and they wouldn't be able to function properly. They wouldn't cause any damage to the jake brake by doing this they just don't work. Whoever changed the injectors and this problem showed up..........screwed up. I have to double check myself every time I do this against the service manual, depending on the style of bolts holding everything in place. CAT changed the bolts and issued a Technical Service Bulletin about this problem years ago. Some engines have the new style bolts and some don't..........you have to remember or check your work against the TSB or service manual


As far as missing the lobe wear on the cam, if the mechanic doesn't rotate the engine or run his finger around each lobe, I can see how it was missed. Injector lobes aren't like a valve with a lash adjustment, so they don't get loose and start making noise like a valve does.