1. Describe the problem you are having in detail: Started the truck up tonight after using it off and on all day today, started hard and had a really choppy idle, gave it some fuel to "clear it out" and it blew lots of black smoke from the tailpipe and ran very very rough. Took it around the block where it stalled twice and I couldn't give it more than half throttle. It EVENTUALLY gets up to speed, but you can't push it or it misfires, bucks, chugs, coughs etc. Got to the gas station and shut it down. Fired it back up 5 minutes later and it continued to idle rough. pulled into the street where it stalled. Angry at this point, I started it back up and revved it to 3000 RPM and it finally tripped the service light and then the idle smoothed and it ran ok. Under load it still misses chugs and coughs but does not stall anymore.

2. Year of truck (http://www.dieselplace.com/forum/#)/engine. 1994 GMC Yukon 6.5TD
3. Odometer reading (indicate miles or kilometers). 141.950 miles
4. Indicate the model number on the Injection pump (starts DS4 or DB2......). DS4
5. Indicate if you know if it’s a 1500, 2500, 2500HD, 3500, 3500HD. 1500
6. Do you have an EGR on the engine? (An F or an S engine code 8th VIN digit) EGR engine with engine cover removed.
7. Air Filter condition (visual check). New
8. Fuel filter condition (freshly changed, mileage (http://www.dieselplace.com/forum/#) since changed). 2000 miles since change, clean in appearance
9. Location of PMD/FSD (http://www.dieselplace.com/forum/showthread.php?t=39436)? (ex. on pump/remote over intake, behind bumper). Behind front bumper on a heat sink
9a. If remote mounted, describe wiring harness (homemade or purchased from which vendor). Purchased from ebay, 6-foot wiring harness.
9b. Indicate the location and condition of the FSD/IP grounding wire. Grounding wire is in stock location
10. Outside Temperature (C or F). __55F___ °

11. Service Engine Light while running?- on/off/intermittent On before scan, off after but codes are stored.
11a. Service Engine light does glow during start/cranking/bulb check: Yes/No Yes
12.Have you scanned for engine codes? Yes/No Yes
12a. List exact results on engine codes (http://www.dieselplace.com/forum/dtc.php). 18, 35, 78, 84, 99

13. Condition of Battery terminals (removed, cleaned and tightened). New and clean
14. Known condition and age of Batteries. 2-3 years old, matched pair
14a. Are batteries a matched set of same age? Yes
15. Condition of Major Grounds (http://www.dieselplace.com/forum/showthread.php?t=157085) (removed, cleaned and tightened) Cleaned and tichtened 3 weeks ago.

16. Does engine crank, or "turn over"? Yes
16a. Does engine start and run? Yes
17. If engine does not start- Crack injector line (http://www.dieselplace.com/forum/showthread.php?p=2188140#post2188140): do you have fuel? Yes/No
18. Does your Wait To Start light come on? Yes
18a.Number of seconds WTS light is lit. Varies, 4 -15 seconds
19. Engine Cranking speed (if you have an accurate tachometer). Enough to start it

20. Are you experiencing Stalling? I was, but after revving it at idle and setting DTC's it hasn't stalled
20a. Describe the event (upon startup only, down the road, hit a bump, etc...) Constantly. Started with a warm start-up. Have not had the chance to test during a cold start.
20b. Do you notice loss of dash or instruments? No
21. Check turbo inlet and air filter for obstructions. Clear, turbo is operating normally.
22. In a no-hot start, pour a bottle of room-temp water on the injection pump. Does it start now?
23. Lift pump test (http://dieselplace.com/forum/showthread.php?t=39350) - Describe results. Pass, fuel from t-handle tube as well as at fuel filter

24. Upon cold start, does the radiator hose get hard quickly? Yes/No
25. Upon cold start, do you have excessive white smoke? Yes/No No
26. Do you have excessive cranking time before the engine starts? Yes/No At times
27. Have you used the block heater? Does it affect engine starting? (only try for starting problems).
28. Are all glow plugs in proper working order (http://www.dieselplace.com/forum/showthread.php?t=39182)? Yes, new

29. During hard acceleration, do you have excessive black smoke? Yes/No No
30. Do you have any unusual exhaust smoke issues? No
31. Turbo check out (http://dieselplace.com/forum/showthread.php?t=39368) - Pass/Fail Pass
32. Indicate fuel that you are using: Bio-Diesel, #2 Diesel, SVO/WVO, other State required Bio-Diesel
32a. If running Veggie Oil fuel setup, indicate details of your conversion (homemade or packaged system).
33. Are you using any fuel additives? If so, please list. No
34. Upon unscrewing fuel cap, do you have a large vacuum formed in the tank? Yes/No No
35. Do you have any service history available that might pertain to the problem you are having? New PMD and relocation to front bumper, different symptoms from when the PMD died.
36. Please indicate any modifications to the vehicle that might help us diagnose better. Remote location PMD, 3" down pipe, 4" exhaust.

84 and 99 are acclerator pedal position faults. A bad APP can cause a bunch of other codes to come up.

Where is the APPS located?

My guess is at your gas pedal!!!! Accelerator Pedal Position Sensor?

Here is a test for the APP. Don't be so quick to jump to the pedal... these ecm's are quite sensitive. Is the PMD new or used? Double check fuel system for leaks, possibly a bad fill up at the pump, grounds for good connection you know the simple things first. I had a load of codes on my '95 once.The knowledgeable guys on the forum told me to change the fuel filter and clear the codes... never happened since:)

The second page of the diagnostic instructions is missing. Can it be posted?

New accelerator pedal and position sensor. Old one failed the voltage test. Hard starting now, once running, runs great cold, but once warmed up it spits and sputters (no stalling) at 3/4 to full throttle. Excessive white smoke on start up - no coolant in oil or oil in coolant. Going to re-examine fuel lift pump tonight extensively. Any other ideas? I'm also going to attemp to take off the filter housing to gain access to the fuel heater and lines and verify those are in working order and tight. Any other suggestions?