Engine/Transmission (1998.5 - 2002) funny cruise control

[Wyomingcowboy]

When driving in cruise control and heading down steep grades my engine feels almost like it's surging. I'm basically coasting down hill and my speed is not running away. I'm guessing it's nothing to worry about but I never noticed this before the engine/ transmission rebuild. Anyone else experience this?

 

[BILLVO]

Mine did that when the VP44 started to die, it was the first symptom, Check the codes.

 

[MKreiberg]

Veeery interesting. I just noticed mine doing it, and I'm in process of trouble shooting an intermittent miss... think my VP may be on its way out...

 

[jeepit]

When driving in cruise control and heading down steep grades my engine feels almost like it's surging. I'm basically coasting down hill and my speed is not running away. I'm guessing it's nothing to worry about but I never noticed this before the engine/ transmission rebuild. Anyone else experience this?

Check for codes... 121,122

 

[Wyomingcowboy]

I'll check for codes tomorrow but it only does it when in cruise and coasting down hill. Never a problem one any other time. Feels almost like a cruise control problem. (I hope, anyway. )

 

[SnoKing]

When driving in cruise control and heading down steep grades my engine feels almost like it's surging. I'm basically coasting down hill and my speed is not running away. I'm guessing it's nothing to worry about but I never noticed this before the engine/ transmission rebuild. Anyone else experience this?

If it has the vacuum cruise control, put a restriction in the line to the vacuum unit. Just needs a pin hole to work right. I used a piece of red tube from WD40 can. There is a T on the firewall. Put it in the line that going to the vacuum unit under the drivers side battery.



SNOKING

 

[BILLVO]

but it only does it when in cruise and coasting down hill. Never a problem one any other time. Feels almost like a cruise control problem. (I hope, anyway. )

That is exactly what my 02 did as the first VP44 dead sign. A week later it was hard starting.

 

[Wyomingcowboy]

No codes present. I guess I just get used to it or wait for something else to pop up.

 

[Joe Mc]

Might want to shop around now for the best deal on a VP, proactive vs. reactive. Typically when the VP bites the big one it's the worst possible time . . .

 

[muchsnow]

cruise control bucking..

No codes present. I guess I just get used to it or wait for something else to pop up.

You ever get a fix on this? Mine's doing the same thing after coming over a hill on the downside on cruise control.....

 

[Wyomingcowboy]

no fix to the problem but it's still doing it. The conditions haven't changed, either. ONLY in cruise control and ONLY down hill. Mine is very subtle as well

 

[SnoKing]

OK, as I point out earlier, the vacuum cruise control will hunt a bit with a tight torque converter, injectors and advanced timing. Putting a restriction in the vacuum line help slow down the action of the vacuum cylinder. SNOKING

 

[Wyomingcowboy]

That's all fine and well but I do not have a vacuum operated cruise nor a torque converter.

 

[muchsnow]

Same here... 6 speed HO... hasn't done it for a bit though. . did change the diff speed sensor and reseat the CPS...

 

[Joe Mc]

That's all fine and well but I do not have a vacuum operated cruise nor a torque converter.

Just a question on the "I do not have vacuum cruise" so when you push the cruise on button on the steering wheel and then set, what actually hold the speed? Just wondering cause my 99 has a vacuum system under and forward of the L/Battery tray? Wondering what they did differently in 01. 5?

 

[Wyomingcowboy]

The ECM controls the speed. I know this because of a conversation I had with Pac Brake and also from me trying out an ECM from Cummins that was for an auto trans - it wouldn't work my cruise control.

 

[muchsnow]

Prob just end up trying the cam pos sensor next and cleaning up grounds and checking the charging system for noise... . still "bucks" every now and then. .

 

[CAPTPHIL]

2001. 5 cruise is handled by the ecm. I have a similar problem on rare occasions, could be the J-brake lying to the ecm. Just a thought.

Good Luck Capt. Phil

 

[muchsnow]

2001.5 cruise

2001. 5 cruise is handled by the ecm. I have a similar problem on rare occasions, could be the J-brake lying to the ecm. Just a thought.
Good Luck Capt. Phil

Kinda lost me on the J-brake... ... ... .

 

[Joe Mc]

Kinda lost me on the J-brake... ... ... .

J-brake = Jake Brake, slang for exhaust brake.