Hicuped twice then......

[Guest00]

returning from Tulsa w/ 5th. Went to Tulsa. truck was running ok. speeds 70 - 75 in od, egt 1200 max, boost 26 -30#. On the return trip ambient below 40* about 30 mi E of Amarillo the engine hicuped twice in about 5 sec. could not hold speed in od, could not get lockup in od. ran in 3rd @ 3000-3200 for the next 200 mi. lock up in 3rd ok,could shift in and out of od but no lock up and could not hold speed, in od 2200 rpm, no lock up egt could hit 1500+ boost 36#. In 3rd lu 3k rpm, egt 1250, boost 32#. Stopped at Sant Rosa for fuel and food, 5 min cool down and shut down for 1/2 hour. Started truck and truck was ok again. OD lockup, would hold 2k rpm, egt 1200, boost 24 - 30#.
My questions: why the increase in egt and boost and loss of power??? #ad
. Why no OD lockup #ad
. Which computer would keep the tc from lock up and/or what the " L " is going on. #ad
. If it needed a reflash it would not have healed it's self. I have to assume an electronic component is changing value and causing the puter inputs and/or out puts to go hay wire. Any ideas on which computer could caue this.
DC will not have a clue so they are out of the loop. I will replace what ever puter is failing but don't know which one???? #ad


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2K, 2500, Laramie, Quad, 4x4, 3:54LSD, A/T, reese 15k 5th slider, EASLEY BULL BAR, WESTIN NERFS, TA's, 9000's, DD2's, Bully Dog Boost & elbow, ISSPRO pyro & boost, Turbo Lifesaver, JARDINE 4", DTT VB,TC,TC SAVER and AUX COOLER, PAC BRAKE, MAG HYTECH TP& DC, onboard.
pullee #1 26' Arctic Fox 5th
#2 22' car hauler w/ 76 Pinto 392cid or 68 Cyclone GT Cobra Jet FB
NRA-LIFE, VFW-LIFE, SOC-LIFE, SASS

[This message has been edited by JNutter (edited 02-12-2001). ]

 

[Guest00]

got lost ^^^^ up up ^^^^

 

[TowPro]

I think I remember reading in the owners manual of my 96 (not diesel) that if the trans temp goes high, the trans will force a OD lockout, to lower the trans temp.

It will also force a OD lockup when its real cold out, until the truck warms up.

 

[John Dimartino]

It sounded like you blew a boost hose-till i seen you still had 36 psi of boost. That is weird,slounds like you have an exhaust restriction,high boost and EGT at the same time-but how did it go away?after shutdown.

 

[Big MAK]

Jnutter, I also think when the transmission gets too hot it's 'puter spins you down (TC unlock). If you compensate by applying more power then you have a vicious cycle (more fuel, more heat, more boost).

Just an observation: you're running that truck awfully hard. I know they're built to take it but I'd be nervous about sustaining 1200 EGTs indefinitely -- there may be a hot spot that's above that -- like maybe cylinders 1 and 6. I don't like sustaining any temps higher then 1000 myself. Of-course I'll spike it up to 12,13,14,even 1500 for just a second or two, but a sustained 1200 is pretty hot. JMO.


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Big MAK
98. 5 ISB 5spd 4x4 Quad Cab 3500, 275s and Original PowerMax
A "WARRANTY FREE" ZONE
https://www.turbodieseltrucks.com

 

[icarus33]

I think the cycle Mark spoke of is what occured. From what I can tell from my '98 manual on the 47re; The PCM located at the passenger side firewall controls the converter lockup clutch, overdrive clutch, governer pressure solenoid.
transmission fluid temp; A fluid temp thermister controls engagement of fourth gear overdrive clutch, converter clutch, governor pressure. Quote " If fluid temperature exceeds 126c (260F), the PCM causes a 4-3 downshift and engagement of the converter clutch.
Also in Converter clutch engagement; Inputs that determine engagement are coolant temp, engine rpm, vehicle speed, throttle position.
There are also a few trouble codes that can be set for transmission issues, but they all show that they would have illuminated the check engine lamp.
I have OBD-II software on a laptop that we could run a scan on your truck if you're interested.



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'98. 5, 2500, 4x4, LB, QC, AUTO, 3. 54 rear, Snugtop, Rhinoliner, ISB, non Cummins enhanced ECM, DDIIIa injectors, K&N, Transgo Diesel shift kit, KJones TC, Autometer boost, transmission temp, digital pyro, Mag-Hytec diff/transmission cvrs. , Redline lubed.