Ilikebikes

Truck - '93, piston pumped (soon to have a large electric pump, I hope), big EDMs, Hybrid WH1C/14WG over a BHT3B/26. Fuek filter replaced a few thousand miles ago.

I took out my DDP4s and put in the EDMs. At idle and maybe a few hundred RPM above (I have no tach yet ) I've got a weird miss. It clears up just fine after that. It isn't too bad, but its enough to make the whole truck wobble and you can hear it in the exhaust. It just doesn't run as smooth as a cummins should. I've bled each injector one at a time while the engine was idling and it didn't help. Could I possibly have some air somewhere in the injection pump that hasn't bled out? I did have injectors out of the truck for about a week. Or is this just a symptom of huge injectors? Never had this problem with my old DDP4s.

Any help is appreciated!

bobva

crack the fuel return banjo bolt 17mm I do believe.
the hand pump your lift pump that will get all the air out. then rebleed lines.

had the same problem

hope it works 4 u
Bob

flashgordon

Could be, you need more timing with your bigger sticks

Flash.

Ilikebikes

I'll try cracking the banjo bolt.

My timing is almost maxed right now. The previous owner of these injectors ran his truck a tooth or so advanced, so I may even need more...

Ilikebikes

Just got in from bleeding the return line (yes, it is a 17mm) and then the injectors again. Can't tell a difference. Maybe this is a symptom from huge injectors (6x18)?

JD730

Can you narrow it down to what cylinder it is? Mine had a shake to it with POD's, now with a set of 6x16's it has a partial miss in #3, not an injector either. When I crack injector lines #3 does not fire fuel out like the rest do, the change is slight also. Runs good otherwise.

I think Josh had his timing 2 teeth advanced, mine is only 1 tooth and my timing is set at 2.01mm if you have the timing tool to check the pump.

Ilikebikes

I'll have to see if I can tell a difference when I crack the injector lines. I think that is that best way to put it - not too much of a miss but a "shake".

I know that josh was running WAY advanced. Who knows, maybe I'll have to do the same thing.

JAyers

Yea I was jumped two teeth. It still idled kinda ruff. I was consered about this when the injectors were new. Called scheid and was told it was normal for injectors this size, had em pop tested anyways just to make me feel better...they were all good. Talked to a local diesel shop and he also said it was normal. I know as long as youve got the timing and air, HOLD ON! Ive put some stock injectors in my truck for a wile (very smooth) then switched to a set of 5x14's and it idles ruff again, not quite as bad but you can tell a difference. Hows that baby runnin? Havent heard anything from ya bout em.

JAyers

I believe your old DDP4's are smaller then the 5x14's that I have now.

Ilikebikes

Thanks for the response, Josh. I think it probably is huge injector related. Again, it's not even much of a miss, just a rougher idle that shakes/vibrates the engine, and in turn, the whole truck .

These things sure spool up my turbos faster than before! I haven't held the pedal to the floor just yet (dealing with issues of keeping the secondary boot on) but my 60 PSI boost gauge is worthless. These injectors pegged it so fast I nearly soiled my pants! I'm getting a 100PSI tomorrow and I'm going to use my 60 PSI gauge for primary boost numbers. Hopefully then I'll really be able to tune my wastegate and see how I'm doing. The only thing I'm concerned about is that I've heard that a WH1C/BHT3B twin set shouldn't really run more than 50 or 60 PSI, anything more than that and its no longer efficient (plus lots of drive pressure). But whatever, I'll cross that bridge when I get there.

Also getting myself some head studs for Xmas .