I hope someone can describe the misfire detection feature in the 6.5td 98 and newer.
I hope someone can describe the misfire detection feature in the 6.5td 98 and newer.
99 GMC SUB, 2500, 4x4, 6.5 TD (F) #H32 enhanced blk, Phaser timing set, B&D IC, 3" ATS exh, K&N w/prefilter, 4WD NVG 246, 4L80E kevlar Transgo off road/tow mods/B&M supercooler, 14 FF MagTec w/locker 3.42:1, 9.25" IFS frt/diff 3.42:1 w/ARB locker, AutoMeter Boost & pre-turbo pyro meter, 12,000 lb hydro winch, Warn classic bumper w/brushguard & diesel scoop, Max E-torq Stage 3, hi pop inj, oil bypass sys, on board air comp for front ARB locker & tire inflation, DynaView driving/auto-cornering lts, DZ nerfs, A/T 285/75/16 SilentArmor 3750 lb rated on 3750 lb rated Alcoa, 3 IP drivers 2 r spares.
Monitoring misfire(s) and their related trouble codes were added to the 1996+ OBD II systems for emissions reasons. The PCM monitors the contribution of each cylinder to crankshaft rotation - via the Crankshaft Position Sensor (CKP). The DS4 & PCM have the ability to adjust fueling for each cylinder, to produce a smoother running engine. The trouble codes are also useful to identify a weak cylinder - due to a bad injector, leaking injector fuel line or out of spec cylinder compression.
Jim
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My scanner detects a misfire but no codes, no rough running has lots of power what should I be looking for?
99 GMC SUB, 2500, 4x4, 6.5 TD (F) #H32 enhanced blk, Phaser timing set, B&D IC, 3" ATS exh, K&N w/prefilter, 4WD NVG 246, 4L80E kevlar Transgo off road/tow mods/B&M supercooler, 14 FF MagTec w/locker 3.42:1, 9.25" IFS frt/diff 3.42:1 w/ARB locker, AutoMeter Boost & pre-turbo pyro meter, 12,000 lb hydro winch, Warn classic bumper w/brushguard & diesel scoop, Max E-torq Stage 3, hi pop inj, oil bypass sys, on board air comp for front ARB locker & tire inflation, DynaView driving/auto-cornering lts, DZ nerfs, A/T 285/75/16 SilentArmor 3750 lb rated on 3750 lb rated Alcoa, 3 IP drivers 2 r spares.
Runs great, and I'm stumped!
I cleared the ecm and drove awhile and the misfire is again detected only code I have is recurring code DTC 1656 boost solenoid control circuit however this circuit is functioning.
I'm going to change out Heath Stage 3 ecm today and go back to my L65 HD ecm then drop boost and see what happens from there.
I'm curious if the timing gears built in 2deg advance have anything to do with this issue?
Last edited by DA BIG ONE; 02-15-2008 at 06:35. Reason: add
99 GMC SUB, 2500, 4x4, 6.5 TD (F) #H32 enhanced blk, Phaser timing set, B&D IC, 3" ATS exh, K&N w/prefilter, 4WD NVG 246, 4L80E kevlar Transgo off road/tow mods/B&M supercooler, 14 FF MagTec w/locker 3.42:1, 9.25" IFS frt/diff 3.42:1 w/ARB locker, AutoMeter Boost & pre-turbo pyro meter, 12,000 lb hydro winch, Warn classic bumper w/brushguard & diesel scoop, Max E-torq Stage 3, hi pop inj, oil bypass sys, on board air comp for front ARB locker & tire inflation, DynaView driving/auto-cornering lts, DZ nerfs, A/T 285/75/16 SilentArmor 3750 lb rated on 3750 lb rated Alcoa, 3 IP drivers 2 r spares.
The advance won't have any effect on the boost solenoid.
Is your SES on? If not, it could be a glitch code, or an intermittent code the PCM isn't seeing as serious. Many faults require repetition under certain conditions to trigger the SES. Else, it may store a code in history and continue w/o complaining. Your BH program may be the cause of the code, but there may not be a real problem present. If your OEM computer doesn't repeat the problem, then it's probably no problem.
Always same cylinder? Might give Bill a call
To enhance Jim's input, PCM uses that function to maintain smooth idle under varying load conditions, such as a\c cycling, shifting into\out of drive range, etc.
To test it, kill each injector, noting and comparing rpm drop of all cylinders - weak cylinder will drop least rpm
jd
'96 Dodge 3500HD cc 2wd drw............'89 GMC 3500 cc 4wd drw
5.9 12v #10TST 6sp SBC13-1.375.......6.5TD EFI maxEtorq v2.0 DSG
DODGE makes it CUMMINS shakes it.....4L80E 205 4.10 Dana60\70HD
6 in a row makes it go.......................Grandpa's big truck