Re: Stalling Problem
Posted by HH56 On 2014/2/2 12:23:19
There are 3 sets of contacts in series which control the ground out. The idea is that the ground is applied to ign for such a brief time as to only cause a misfire of three or 4 cylinders and release torque for an instant so the solenoid can pull out. It sounds as if either the secondary relay is sticking or the solenoid is lagging and the ign is being grounded so long the engine stalls. A third but remote possibility is the wire between solenoid and relay in the grounding circuit is able to contact and ground out against the frame
The R9 sequence is when in OD, the contact at terminal 6 of solenoid is closed. At the same time, the secondary relay coil is in series with the solenoid hold in coil so it's contact is also closed. That brings ground to the third contact which is on the main power relay. Since the solenoid is powered, that third contact is now open and no ground is applied to the ign.
When dropping out of OD, the governor or kickdown switch opens ground to the main power relay. It drops out releasing the solenoid but at the same time closing the contact in the ign ground circuit and causing the engine to misfire and drop torque. Once torque is dropped the solenoid can pull out and should open it's contact in short order and remove the ground to engine before it stalls. Since it is mechanical, the secondary relay is supposed to be slightly faster and with the solenoid de-energized, it also opens as a backup. I am suspicious it might be sticking.
The relay is relatively easy to get to so popping the cover and checking the operation is the first part. Disconnect the battery and using a very small point file or some very rough texture ordinary paper, hold the contacts closed and run thru the contacts to check for roughness and to clean them up a tad. Also make sure when you push the contacts together and release the armature it springs right back out. If there is residual magnetism or a weak spring holding the secondary relay energized too long that can cause the issue.
The second check is the solenoid. If the OD is gummed up so the solenoid can't release and pull the pawl out quickly, the contacts can be staying closed too long -- but with the R9 that secondary relay is supposed to prevent that. If you had the R11 that would be the likely suspect.
The contacts in the solenoid do need periodic service. Download the EconoDrive training manual and have a look thru. It has several photos and details on servicing the solenoid.
Attach file:
(41.66 KB)
(62.42 KB)
The R9 sequence is when in OD, the contact at terminal 6 of solenoid is closed. At the same time, the secondary relay coil is in series with the solenoid hold in coil so it's contact is also closed. That brings ground to the third contact which is on the main power relay. Since the solenoid is powered, that third contact is now open and no ground is applied to the ign.
When dropping out of OD, the governor or kickdown switch opens ground to the main power relay. It drops out releasing the solenoid but at the same time closing the contact in the ign ground circuit and causing the engine to misfire and drop torque. Once torque is dropped the solenoid can pull out and should open it's contact in short order and remove the ground to engine before it stalls. Since it is mechanical, the secondary relay is supposed to be slightly faster and with the solenoid de-energized, it also opens as a backup. I am suspicious it might be sticking.
The relay is relatively easy to get to so popping the cover and checking the operation is the first part. Disconnect the battery and using a very small point file or some very rough texture ordinary paper, hold the contacts closed and run thru the contacts to check for roughness and to clean them up a tad. Also make sure when you push the contacts together and release the armature it springs right back out. If there is residual magnetism or a weak spring holding the secondary relay energized too long that can cause the issue.
The second check is the solenoid. If the OD is gummed up so the solenoid can't release and pull the pawl out quickly, the contacts can be staying closed too long -- but with the R9 that secondary relay is supposed to prevent that. If you had the R11 that would be the likely suspect.
The contacts in the solenoid do need periodic service. Download the EconoDrive training manual and have a look thru. It has several photos and details on servicing the solenoid.
Attach file:
(41.66 KB)
(62.42 KB)
This Post was from: https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=138847