Chrysler Repair: 99 grand voyarger trans problem/cruise problem, exhaust gas recirculation valve, exhaust gas recirculation

Question
QUESTION: I have recently had the auto trans on my 99 voyarger re-built, when I got the car back I've found that it stalls when taking my foot of the gas, this happens at any speed and normally when the revs go below 1000rmp, the other thing I've noticed it that the cruise control is no longer working, any help would be great!
Colin UK

ANSWER: Hi Colin,
The engine stalling may be unrelated to the transmission rebuild except for one function, that being torque converter lockup clutch. That device is supposed to function to bring to the same rpm the input and output turbines of the torque converter so as to reduce slippage which improves economy and engine braking. But, the clutch has to unlock as well and if it is not doing so the engine will stall because it is like not using the clutch on a car with a manual transmission...the engine will stall. So notice if possible the difference in how the engine and wheel speeds relate to oneanother. If as you slow down the engine rpm seems to track identically with the velocity of the van then it would be indicative that the clutch is not being released by the transmission controller. The shop that rebuilt the transmission would be responsible for correcting that if it were the cause. Otherwise, the stalling of the engine when coasting may be due to a mixture problem such as the exhaust gas recirculation valve being sluggish in its operation which might be corrected by spraying some thin lubricant (WD-40) on the stem of the valve. A readout of the engine controller via the underdash plug with a fault code reader may also reveal a cause.
The cruise control operates by both electic connections and vacuum. I would check the vacuum hose that supplies that source to the control module. Also check that your brake lights are not accidentally stuck "on" due to a maladjusted pedal switch. Both of those could prevent the normal operation of the cruise. The vacuum connection may not have been re-established when the trans was put back in after repair.
Those are some ideas to consider. Let me know if you do or don't make some progress.
Roland

---------- FOLLOW-UP ----------

QUESTION: Hi Roland and thanks for your very prompt reply! the other thing I forgot to mention is the car now runs very rough at idle, none of these problems exsisted before I took the car to the shop!

Answer
Hi Colin,
That would suggest that something related to mixture probably on the air rather than the fuel side of the equation is involved. A disconnected vacuum hose, maybe the one for the cruise control module for example, would do this, by allowing air to be sucked into the intake manifold rather than the hose being hooked up to a vacuum chamber.
So I would bring that to the attention of the shop that did the repair so that they might check all the vacuum lines. There is a diagram on the underside of the hood, in all likelihood, that shows all the vacuum connections and that can be used as a road map to check all the items. The egr is located in a small pipe that runs from one of the exhaust manifolds back to the intake throttle body area. Let me know which of several possible engines is in the van and I can be more specific as to its location. In any case once you find it you will see the body of the valve is attached to the pipe, and then there is a round vacuum actuator and vacuum hose on its top. In between there is a flange inside of which you will see a rod with a circumferential slot which is the valve stem. You put the tip of a screwdriver in the slot and move the stem back and forth in one direction to see that it moves freely and is pushed to a dead stop by an internal spring in one direction. It it doesn't close tightly then that would cause a rough idle or stall out which as I said earlier can be corrected by spraying the stem where it enters the valve body.
So go back to the shop, tell them the problems, have them check their work and do a fault code check out. By the way there is a fault code (P0740) which applies to the torque converter clutch issue. You might be able to get the fault codes to show up on your odometer window: use the igntion key to turn the ignition "on-off-on-off-on and leave on" doing that in 5 seconds or less. Then watch to see if the mileage reading disappears and a four-digit number appear in its place. It may or may not work. If not, then a readout via the plug is appropriate.
Roland