Well, my truck has a dead miss at idle and a horrid "chug" until about 1500rpm if it isn't under enough load. But, once it gets above 1500rpm it runs like a champ, or as far as I can tell it does anyways. I've had the problem for quite some time now and it all seemed to start as soon as I put in my 100 plate a while back. Not only did it have a minor chug with the stock injectors but my mileage went down the tube... Went from 21+ to less than 15 and now somewhere around 12 with the 370's and the HX40.

I changed the injectors thinking I had a lazy one that popped too high or was a little sticky, no improvement and now I obviously have the 160 pump woes that come with bigger sticks (got the 370's cheaper than I could find a set of stockers even through my diesel parts connections at the shop).

I have a fuel pressure regulator on the way to solve any low fuel pressure issues since I don't have the fittings to test my FP with. Also, will be getting laser cut DV's soon to possibly help with the 160 pump woes...

I am hoping it isn't a scored plunger or maybe a barrel skipped a tooth on the rack I don't know honestly. All I know is that my truck is driving me nuts. I also can't get anymore than 30psi of boost out of the HX40; it has the 16cm exhaust housing and I figured I have enough fuel to see more than that. But I guess not.

I guess I am really at a loss and almost feel as though I should have left my truck alone. I have just always wanted a dodge with a cummins and always had plans laid out for modifying one. I guess I shouldn't have felt so comfortable with bombing it since all my knowledge is with A-pumps and Ag p-pumps which are completely different animals.

Sorry for the long post guys, but I had to vent... I guess I'm hoping someone will know the solution to my woes that doesn't involve a new pump since I'm poor.

 

I think a good start would be to let it cool down overnight, fire it up in the morning and shoot the exh man with a temp laser or temp stick to see which cyl is running up cold, then check the compression on that cyl. Or just check all cyl's. When was the last you changed the fuel filter or run the overhead??

 

I see you have a 94'. Thats the problem, the 160 pump has a miss around 1000 to 1200 rpm which only gets worse with injectors and such. The only way to get rid of the **** miss is to replace the pump. I have done extensive research into this myself trying every little trick somebody claims works and the only thing I have done is waste my time. Get the ag pump or a 215 you will be satisfied.

 

My 160 pump with a #100 plate doesn't have a miss. OP I think you should trace back the problem to when it started. You said that once you put the plate in the chug and horrible mileage followed, so I would try double checking everything there first. Good luck

 

See here's the fun part; I have put a stock plate back in the stock position to see if that helped and nothing improved (other than tire wear ) The dead miss only comes after the engine is warm and has been running down the road for a half hour or so. I have tried using our laser thermometer to find a dead hole and did a compression check when I put in the injectors; all six holes checked out fine... Changed fuel filter about 8 months ago and did an overhead shortly after it started acting up. Probably should change the fuel filter as I have put a lot of miles on in the last 8 months.

All this leads me to believe that it is the pump and I really wish that it wasn't since I don't have the cash for one. I am still waiting for one of my buddies to find an 8.3 and convert it to run alcohol so I can ****** up his pump... I like the Ag pumps better in that they don't have a torque plate at all so the only thing that limits rack travel is the governor and an easier to fool with AFC (as far as rack travel adjustments).

I do know of a reputable diesel injection shop that we have a business account with that I may send my pump to. They build all the pumps and even a lot of the turbos for the local truck/tractor pullers around here. I just wish I had the money

 

Well I did three things yesterday that seemed to have helped;
1) Cleaned my air filter (it was almost plugged)
2) Changed my fuel filter
3) Bumped my idle up to 900rpm (was around 650-700)

I got my mileage back and my truck idles smoother, yet it still has a random dead hole at idle after it is up to operating temperature. The chug is almost gone, though it is still there for about the first 150-200 rpm which is better over it's previous span of close to 500rpm. I still think my pump is a little on the weak side though and still don't really know what to do. Hopefully I turn out to be a good salesman and make good money at my new job