99 Cummins - new to me pickup - that has issues

[jlbayes]

It depends on the options as I said. If a controller that has security but does not see it on the truck...it will shut it down after it writes it to the cluster. Most emissions testing facilities get pissy about the mismatch as well.

[01_Cummins_4x4]

I wonder if my pumping vacuum into the vacuum line that's hooked to the vacuum servo, might have unstuck the diaphragm in the cruise control servo? For shits and giggles on the way home from work (20 miles each way) I hit the cruise control button and the light lit up and then I hit the set button and it was working. I tried the resume and accel buttons and they work too. All I know is that I'm super happy to have cruise control working for once on this pickup.

 

Now onto the trans. When under heavy or full acceleration, the trans seems like it shifts from 2nd to 3rd, and then instantly shifts back to 2nd (rpm raises 500 rpm) and then it accelerates and shifts into 3rd gear and then it shifts into OD after a bit. 

 

Can someone explain what the governor pressure solenoid, the transducer, the OD lockup solenoid functions are for the auto trans shifting? Since it seems to be a 2nd to 3rd shifting issue, and the rest of the gears feel great, no slippage, I'd like to get it fixed ASAP.

 

Thanks!

[01_Cummins_4x4]

I guess the trans still shifts weird from 2nd to 3rd at any other time, and not just under heavy acceleration.

 

[Mopar1973Man]

Might contact @Dynamic and see what he's got to say about you transmission issue. 

[bigfish95971]

ECM is bad so get that one on, it is the correct part number for all 98.5 and 99.  Takes les than an hour.  Just remove bolts and plug.  Probably bad from AC from the alternator, which may be causing other issues too.    Miss may be bad ECM, if that does not fix it it may be a bad injector if it is intermittent miss when warm.  Good luck with the rest of it.

[01_Cummins_4x4]

23 hours ago, bigfish95971 said:

ECM is bad so get that one on, it is the correct part number for all 98.5 and 99.  Takes les than an hour.  Just remove bolts and plug.  Probably bad from AC from the alternator, which may be causing other issues too.    Miss may be bad ECM, if that does not fix it it may be a bad injector if it is intermittent miss when warm.  Good luck with the rest of it.

 

Update, my TV cable was about 1/2" out of adjustment. I re-adjusted the TV cable and it does shift more normally now. I took my pickup to my friend that owns a Transmission specialty shop, and he drove it and said that the torque converter shudder is because the previous owner left the TV cable out of whack too long and it has ruined the lockup on the torque converter. 

 

bigfish - don't you mean PCM as it controls the auto transmission, cruise control, voltage regulator, etc?

[bigfish95971]

Nope, the op stated he had a delayed boot up and WTS light.  This defines a a bad ECM and he had one already acquired.  So the first step is to fix already known problems with parts already on hand.  Yes it is separate issue from PCM.

But often lockup and OD issues are related to AC from the alternator which is also what caused the and will continue to cause the damage to the ECM.  The truck needs to be thoroughly checked for AC before before getting into the PCM or Torque convertor.  Throttle cable will cause shifting issues, but AC more likely causes lockup issues.

Edited January 16, 2018 by bigfish95971

[jlbayes]

Lock up cycling and converter shudder are very different issues. Keep that in mind.

[Mopar1973Man]

Shudder is either wrong fluid used or the clutch is plain worn out. 

 

Lockup cycling in and out at 40-50 MPH range typically is an alternator AC noise issue. 

[bigfish95971]

Correct.  I was just suggesting the OP start with known issues get fixed first and then see what is left and work on them.  Sometimes  fixing one thing fixes others.  I wonce had shuddering issues on a stock TC and it turned out to be too much power from the ChiP and VP set up I had.  Backed off and has been fin ever since.

Some times some shuddering, flaring or slipping can be bad clutches in the OD in it too.  Sometimes Lucas additive can help for awhile.

[Mopar1973Man]

1 hour ago, bigfish95971 said:

I wonce had shuddering issues on a stock TC and it turned out to be too much power from the ChiP and VP set up I had.  Backed off and has been fin ever since.

 

Another valid case of overwhelming the torque converter clutch and the clutch not capable of holding the power.

[bigfish95971]

Yea, I did that by accident..  I had a HO VP on it and it ran well. I put back on my BD Van Aaken Plug and Power for my SO VP.  It felt like it gave it 200 more HP and I got shudder when I gave it throttle up hill.  I took the Chip off and it ran fine for 5 years with the HO and had plenty of power (more than stock SO, similar to SO with chip) and I ran it that way for 5 years until I put an SO pump and the chip back on 5 years ago.

[01_Cummins_4x4]

My trans is not cycling (hunting) between OD and 3rd at all. I just have a shudder in OD only and is only really felt when on light load throttle application. 

 

I don't have any tuners or chips on the pickup at the moment.

 

Edited January 16, 2018 by 99_Cummins_4x4

[bigfish95971]

Are you saying  it is fine under heavy throttle?  By shudder do you mean a rapid vibration?

[01_Cummins_4x4]

It is more noticeable under light throttle like when driving up a hill, but I believe it's there under full throttle acceleration as well.

 

The shudder does feel like a rapid vibration.

[JAG1]

My thought is that the diesel engine is more capable of causing shudder in the taller gears since every time a cylinder fires torque to a turning crank it places more stress on a more slowly turning trans than if in faster turning trans or lower gears.

 

Problem is the fun of feeling the torque the cummins is capable of even in taller gears.........

[IBMobile]

Torque convertor lock up clutch slipping. 

[bigfish95971]

TC slipping can be a rapid shudder.  But Lockup issues is not going in and out of third and 4th.  It is going in and out of lockup while in 4th or 3rd if OD is locked off.  It will repeatedly jump 2-4oorpm and then back to lockup, not usually called a shudder by most.