New here, but been reading a lot (both here and elsewhere) and a new diesel owner.
1996 Automatic F250 XL with 7.3 PSD 170k+ miles, AFE Big Boost intake, everything else stock.
Rough loping idle at start only, regardless of engine temperature. Once throttle depressed approximately 1/2 inch, to bring RPM up to 1000 RPM, then slowly released completely, idle stabilises.
Accompanied by very slow throttle response which is especially bad when cold (for my purposes throttle response being the rate of acceleration with the throttle fully depressed).
Can you post a vid? These first Gen Power Strokes aren't as bottom end friendly as the newer trucks They LOVE to play above 2000RPMs. On each head at the valve cover there are two (each) injector/glow plug connectors. Remove each connector and inspect the insides for oil (should be clean and dry) and burned pins (should be bright and shiny).
As soon as RPM above 1500, one can feel turbo boost commence and throttle response improves. Runs smoothly at higher RPM.
Normal for a stock turbo. With the stock turbine housing you are not going to see good usable boost till about 1600RPMs but more like 1800RPMs. Again look at the VC harness like stated above.
When revving up and abruptly releasing throttle, the engine would falter and drop below 500 RPM, at times dying out.
HHmmmm...Possible weak HPOP (high pressure oil pump), IPR, ICP, or shorted wiring harness.
Had water in fuel light illuminate intermittently (on right hand turns) a couple of times, whilst burning through both tanks, drained fuel bowl a couple of times when that happened, problem has not presented itself again.
Sounds like you got a handle on this. With winter on us (I don't know where you live) look into a winterizing fuel additive (like Diesel Kleen [white bottle] from Power Service at your local parts store). Diesel turns to jelly when it gets cold enough. The truck can't inject jelly. Winterizing additives keep the gelling at bay.
Transmission shift points are kinda all over the place, sometimes shifts smoothly (usually the lower gears) then abruptly for higher gears, sometimes not shifting to OD by 3000 RPM requiring me to throttle down somewhat, then it shifts.
PCM controlled. Like you said, get a handle on the engine issues and the tranny may smooth out. Also, when was the last tranny fluid swap? Look to see if the fluid is bright red and absolutely clean. Does the speedo needle jump around as you accelerate?
Assuming shifting issue to be unrelated to engine running issue at the moment. Not addressing until engine resolved.
Corrective actions taken:
(I attempted to accomplish the cheapest alternatives first)
- Changed engine oil (Delo 400) and filter (that's a lot of oil!)
- Changed fuel filter (in water separator housing); quite dirty.
- Replaced Exhaust Back Pressure (EBP) pipe & sensor; both totally blocked with fouling
* IAW Welcome to guzzle's Exhaust Backpressure Sensor Cleaning Maintenance Web Page)
* purchased at DFUSER Diesel Performance Products Exhaust High Performance Part Diesel Intake Diesel Power Chips
- Previous owner replaced Camshaft Position Sensor (CPS), then I changed it again, with blue international version, just to be sure.
* IAW TikiWiki : P0344 Camshaft Position Sensor Circuit Intermittent
* purchased at Improved Blue CPS for 7.3L Ford Powerstroke Diesel
- Engine Control Module (ECM) was replaced by previous owner in an attempt to address this problem.
- Previous owner replaced mechanical fuel pump.
- I connected an OBD2 analyzer; no fault codes stored statically and no problems found on running tests.
No noticeable improvement.
Clutching at straws now (well, I have been since I started, but hey!), I will be pulling the Fuel Pressure Regulator (FPR) screen.
* IAW FPR Screen cleaning writeup - Ford Truck Enthusiasts Forums
Other than that, i am kinda at a loss. I did read elsewhere that the turbo veins may be stuck open??
* Low Power Until About 1500 RPM - PowerStrokeNation : Ford Powerstroke Diesel Forum
Any advice or suggestions would be greatly appreciated at this point.