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Stumped. Bad idle on 6.5 Please HELP.

Dieseldad97

I now know why.
Messages
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Location
Altona, Manitoba Canada
I stole this checklist...I hope it's ok to use it one DTR. Please help my buddy figure out why his truck idles like crap. Thanks.
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0. Describe in detail the problem you are having. Please be as descriptive as possible. TRUCK WILL MISS AND PUFF BLUE AND BLACK SMOKE AT IDLE. WHEN IT REVS UP PAST 1000RPM IT RUNS GOOD. LOTS OF TIME AND PARTS HAVE BEEN INVESTED AND STILL IT WILL NOT RUN RIGHT.
1. Does the engine crank, or 'turn over'? YES
1a. Does the engine start and run? YES
1a1. If the engine does not start - Crack injector line: do you have fuel? Yes/No YES
1b. Do you have a Wait To Start Light & the amount of time (seconds) lit. YES/5-8 SEC
1c. Ambient Condition (temperature outside indicate F or C) __20 C___ °
1d. Engine Cranking speed (if you have an accurate tachometer). FINE/ NORMAL
1e. Are you experiencing stalling? NO
1f. If Stalling, describe (upon startup only, down the road, hit a bump etc)
1g. If Stalling, do you notice loss of dash or instruments?
-note if experiencing stalling,you must indicate PMD location in #24.


1h. Check turbo inlet and air filter for obstructions. Cone filters have lost disk and stopped air to turbo.
1.1 Lift pump test - describe results NEW PUMP
2. Service Engine Light while running?- on/off/intermittent OFF
2a. Service Engine light does glow during start/cranking/bulb check: Yes/No NO
3. Model year 1995
3a. Odometer reading (indicate if in miles or km) 400,000 KM
3b. Miles on major engine components if been replaced (example Injection pump) 1000 MILES ON SS DIESEL HEADS
3c. Indicate the model number on the Injection pump (starts DS4 or DB2......) NOT SURE
4. Have you scanned for engine codes? (varies by pre/post 96) yes/no YES
5. List exact results on engine codes: EGR IS DISCONNECTED
6. Air Filter condition (visual check) K+N NEW
7. Fuel filter condition (freshly changed/condition unknown/mileage since changed) 6 MONTHS OLD
8. Condition of Battery terminal connections (removed, cleaned and tightened) PERFECT/CLEAN
8a. Known condition and age of the batteries. 1 YEAR OLD
8b. Are batteries of differing age or are they a matched set? MATCHED
8c. Condition of Major Grounds. (same drill as batt - removed, cleaned, retightened) ALL GROUNDS GOOD/CLEAN
9. Upon cold start, does the radiator hose get hard quickly? Yes/no NO
10. Upon cold start, do you have excessive white smoke? Yes/no NO
11. Do you have excessive cranking time before the engine starts? NO
12. Have you used the block heater, and does this effect engine starting?(only try for starting problems) N/A
13. During hard acceleration, do you have excessive black smoke? Yes/no NO
14. Do you have any unusual exhaust smoke issues?YES, PUFF OF BLUE AND BLACK WHILE IDLEING
15. Turbo check out - pass/fail NO TURBO N/A 6.5
16. Do you have an EGR on the engine? (An F or an S engine code 8th VIN digit) YES,NOT CONNECTED
17. Indicate if you know if it’s a 1500, 2500, 2500HD, 3500, 3500HD. 1500
18. Indicate fuel that you are using: Bio-diesel, #2 Diesel, #1Diesel, SVO/WVO, other SUMMER DIESEL
18a. If running a VO (Veggie Oil fuel) setup, indicate details of your conversion (homemade, or packaged system)
19. Are you using any fuel additives? If so, please list.
20. Please indicate geographic region you are in: (example: Texas or Canada) CANADA
21. Do you have any service history available that might pertain to the problem you are having? TRIED NEW PMD...PUMP IS 2 YEARS OLD
22. Please indicate any modifications to the vehicle that might help us diagnose better.NEW HEADS,MARINE INJ. 97 STYLE WATER PUMP WITH TWIN T-STATS
23. Upon unscrewing the fuel cap, do you have a large vacuum formed in the tank? yes/no NO
24. Location of PMD/FSD? On the pump/remoted over intake/remoted out of engine bay (please specify placement specifically) MOUNTED INSIDE AIR CLEANER BOX
24a. If remote mounted, describe wiring harness (homemade or purchased from a vendor?) KENNEDY HARNESS
24b. Indicate the location and condition of the FSD/IP grounding wire. GROUND IS ON THE PUMP
25. Are ALL glow plugs in proper working order as per this thread? YES
 
Never mind DD yours is the 97 in sig, his is a 95 no MAF, anyway why isn't he here posting we won't bite :D still like to know about how he blocked EGR, also when he did heads, did he replace the "mystery gasket" between upper & lower intakes, what is wg doing at idle opening a little possibly, wire it fully shut for test to see if things improve
 
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Yeah I know Tim. I told him to join our group and he didn't seem too interested. I'll keep trying though.
As for his gaskets...I'll have to ask him.
His is a N/A 6.5 with no turbo, so no w/g to worry about.

This thing runs terrible at idle.
 
6.5 n/a ,

DS4,

any possibility you have timing too far advanced, that is what symptoms are sounding like if DS4 IP where is fuel s/d solenoid positioned, more to 12 or closer to the stat housing
 
6.5 n/a ,

DS4,

any possibility you have timing too far advanced, that is what symptoms are sounding like if DS4 IP where is fuel s/d solenoid positioned, more to 12 or closer to the stat housing

Are you talking about the OS timing? Or can the pump be scewed left or right a bit to adjust timing?

Thanks.
 
IP base timing itself possibly too far advanced, what is the avg timing reading in time set command?

There are 2 components to timong me & aces went through this yesterday on phone, time set which is what ones does after a IP replacement & I like to do acter PCM swap, using a bi-directional scan tool time set is activated, at which point desired/commanded goed to 0 deg and actual timing should run about 3.5 deg avg, rotate IP as required to get you there, I prefer my avg to about 3.6/3.6 degrees.

Then the next thing to check is Top dead center offset (TDCO), in OBD-I you need a scan tool to command this, with obd-II it can be initiated with ignition key to run/on (not crank) and app to floor for 45 sec min, after 45 sec on then 30 sec min with ignition off, if no codes are stored, and water temp is above 170F then the TDCO learn will activate, -.25/-.75 is factory TDCO, & -1.5/-1.94 is where better performance is attained.

Time set & TDCO are 2 different things, though both may require moving IP, time set may require a big move, and TDCO a little movement.

Optic bump is a whole different approach where IP top cover is removed, and optic sensor is moved off it's null position and locked down in an advanced time setting, can be problematic to those not sure of how to bump optic sensor mechanically, I prefer using the computer and advancing via TDCO commanded advance.
 
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My buddy was told that this running so erratic may be the fault of his accelerator pedal. Could that cause the symptoms of a bad idle? The truck cannot be driven, it's that unpredictable.
 
Broken armature maybe? I don't remember if I had any missing and/or popping out the stack though when mine went..
 
I think you can test the pedal by driving with cruise control on, if it dont do it any more(with cruise on), it aint it...
 
My buddy was told that this running so erratic may be the fault of his accelerator pedal. Could that cause the symptoms of a bad idle? The truck cannot be driven, it's that unpredictable.

You didn't mention THAT before, DD... just that idle smoothed out at higher rpm...

DD97 said:
TRUCK WILL MISS AND PUFF BLUE AND BLACK SMOKE AT IDLE. WHEN IT REVS UP PAST 1000RPM IT RUNS GOOD

I'm confuzeled enough without leaving out little details like that :)

Just how bad is it? Does it surge? Does it fail to respond at all? Can you hold it at a steady rpm or not? Does the cruise control help?

Inquiring minds want to know...
 
You didn't mention THAT before, DD... just that idle smoothed out at higher rpm...



I'm confuzeled enough without leaving out little details like that :)

Just how bad is it? Does it surge? Does it fail to respond at all? Can you hold it at a steady rpm or not? Does the cruise control help?

Inquiring minds want to know...

Sorry if I'm not making any sense. The truck runs smooth on high idle and when it kicks off....it will almost stall, then rev up and down like mad.
 
now that kind of revving on it's own sounds suspiciously like a broken fuel solenoid armature stus, not the shutdown solenoid but the one on the IP head, what is timing stepper motor doing when this is occurring
 
OK.....just got back from the truck. Tried a bunch more stuff. Pulled the o/s filter and made no diff. Tried another PMD without Kennedy harness and with it..no diff.
The truck will run perfect over 1000rpm.

We pulled a plug from the firewall that goes into a black plastic thing and that made a difference. The truck ran smooth as silk..YEAH!! But---when we put it in drive, the rpm fell to 600 and it started bucking again.

So to sum it up, after 700rpm..normal. Anything under that real bad bucking.

We did find it a bit wet around 2 injectors...is this bad enough to cause it to miss and buck?

Sorry it's so long guys.
 
Fix that leak, anything that leaks can prevent fuel to injector and air into the system. Yes, it can buck like if you have not bleed the filter after changing. The difference is with the leak, it is continous air supply.
 
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