My 02' CTD misses and jerks in mid-throttle, between 22-30psi boost. It's ok cruusing empty on the highway and full throttle acceleration. It misses and jerks pulling a trailer or during moderate accelaration.
It had stalled a few times on me, so we ran some tests and hooked a VP-44 bypass kit to it. We deemed the VP-44 to be bad. We replaced it, and it doesn' stall on me anymore, but the mid-range fuel miss is still there.

Can a bad injector cause this problem? The FASS 150 lift pump still provides 15-18psi of fuel pressure.
Tomorrow I'm picking up a map sensor to try first before I start pulling injectors to test.

If anyone has an ideas I'd appreciate your input. Thanks.

 

Mine does the same thing. Rev it up to about 2200-2500 rpm and it will flutter and the rpms will jump around a bit. Tried an apps reset, has a new map sensor, HRVP isn't even a year old yet. Between that and the slight miss it has this thing drives me nuts.

 

Fill out your sig...this might give us some more info onto what might be causing the issue.

Your pressure seems good....

 

Here's my signature.

It also has a dead pedal at times when
I coast into town and I want to double clutch it. I ping the pedal after coasting and its dead until I hit the throttle a 2nd or 3rd time....?????

 

Code's or MIL on? When its dead does the Tach work? I had a cam sensor go out and did this....and could be an APPS or VP......

Try the 3 key turn trick to pull the codes........

 

The diag. doesn't bring up any codes. Just put a new VP-44 on it last week.

The tach doesn't die when it does the dead pedal thing. Fuel pressure stays consistent on my diprocal gauge.
Since I have the new map sensor I'll put it in I guess and then try the 3-key.

Not sure if its related, but I forgot to mention that I have the 3 cylinder high idle progamed, and when it's below zero out, which it has been a lot her in northern WI lately, it gets up to that 1200rpm high idle, and then it completely changes sound and rattles like its chugging on 2 cylinders. It won't die, but sounds real bad. Ping the pedal and its gone until it idles up again. If it's just cold enough, say in the teen's or so, it will high idle fine.

I'll try that stuff tonight. Thanks!

 

The 3 cly idle is normal if its get cold enough and will cancle if you hit the brake......like you said. This should have no bearing on your issue. And your right...sounds like heck when it does kick on.....

Check your connection at the VP-44 and also are you running some sort of additive to keep the fuel from gelling up? If you are getting cold enough to kick the 3 cyl.....you are just getting into temps to start gelling the fuel. Granted fuel pressure would reflect this......

I would eye your connections to your APPS and VP-44...might not be on all the way....have seen that before......

 

Alright, good, that scared me the first time. Sounds like the 950 JD on the farm. 3 Cylinder Yanmar D. Guess that's why they sound similar, 3 cylinder!

I have run Schaeffers Diesel Treat 2000 Winter fuel additive in the winter in every tank, and the summer additive to that in the summer in every tank since I bought in new in 2002.

 

I used to be a JD tech at a shop in Texas....haha....that is dead nuts on! haha......Always wanted to make a go-cart out of one of thoes Yanmar's! Stick a small turbo on them.....

 

Well, I tried a new map sensor. Didn't work. Tried a TPS, didn't work. Tried a cam sensor, still didn't work. We've driven around for hours with the scantool on it and it won't throw any codes, and everything is in check, but it still misses from 22-30psi of boost. Put it to the floor boards, and it screams with no misses.

Going to try to put a new ECM in it now. Really confused and frustrated. Nothing seems to fix the problem.