I just purchased a 94 LC with 147,000 gentle miles. One of the things that I first noticed was a high idle condition (1900 rpm) after starting a cold motor. The idle would slowly creep down to the 600/800 range within 3-5 minutes of start and then run relatively normal (that is to say somewhat rough).
Because I wanted to do some of the work on the engine myself, I cleaned it up with an engine degreaser and water. Predictably, the engine ran poorly afterward and since I was having my mechanic replace the front axle seals I asked him to address the rough running issue. He blew the water out of the appropriate nooks and crannies and I thought that would me the end of the problem.
However, when I picked it up (on a friday, after business hours) it was still running rough. I took a peek under the hood and discovered that his tech had not attached the distributor cap and that the rotor had slightly damaged the cap. I attached the cap and he agreed to replace the rotor and cap after his tech took a look. Since he wouldn't have the parts in stock until the next day, I left, but on the way home I got a CEL. I checked my Chilton manual and followed the instructions for acquiring the error code (No. 71). I started by checking the components of the EGR system, which was the system that corresponded with the error code and low and behold I found 2 detached vacuum lines to the VCV and VSV for EVAP (I believe). I reattached the lines, cleared the error code and turned on the ignition (didn't start). At this point I realized that I had not disconnected the jumper. I turned off the ignition, and unhooked the jumper and started the engine. I noticed two things, one, the engine was running smoother and two, the idle problem had gone the other direction.
The engine does seem to run smoother, but if I don't keep my foot on the accelerator, the engine idle will drop and it will eventually stall. I tried resetting the ECM by disconnecting the battery for 30 seconds, but that did not immediately fix the problem.
One thing I am worried about is that I have somehow damaged the ECM by keeping the jumper attached and turning on the ignition. However, I have read posts that would suggest that this should not have damaged the ECM.
I have also read posts that suggest that the ECM needs time to relearn after the battery is disconnected.
Did I damage the ECM and if not how long should I wait to see if the ECM relearns the proper idle speed and given the circumstance does anyone have any suggestions?
I apologize for the wordy post, but I thought the history would help in Dx'ing the problem. Needless to say I also beg your indulgence for any portion of my question that may have resulted from my own ignorance.
Thanks,
This is a test
Tobylima
Because I wanted to do some of the work on the engine myself, I cleaned it up with an engine degreaser and water. Predictably, the engine ran poorly afterward and since I was having my mechanic replace the front axle seals I asked him to address the rough running issue. He blew the water out of the appropriate nooks and crannies and I thought that would me the end of the problem.
However, when I picked it up (on a friday, after business hours) it was still running rough. I took a peek under the hood and discovered that his tech had not attached the distributor cap and that the rotor had slightly damaged the cap. I attached the cap and he agreed to replace the rotor and cap after his tech took a look. Since he wouldn't have the parts in stock until the next day, I left, but on the way home I got a CEL. I checked my Chilton manual and followed the instructions for acquiring the error code (No. 71). I started by checking the components of the EGR system, which was the system that corresponded with the error code and low and behold I found 2 detached vacuum lines to the VCV and VSV for EVAP (I believe). I reattached the lines, cleared the error code and turned on the ignition (didn't start). At this point I realized that I had not disconnected the jumper. I turned off the ignition, and unhooked the jumper and started the engine. I noticed two things, one, the engine was running smoother and two, the idle problem had gone the other direction.
The engine does seem to run smoother, but if I don't keep my foot on the accelerator, the engine idle will drop and it will eventually stall. I tried resetting the ECM by disconnecting the battery for 30 seconds, but that did not immediately fix the problem.
One thing I am worried about is that I have somehow damaged the ECM by keeping the jumper attached and turning on the ignition. However, I have read posts that would suggest that this should not have damaged the ECM.
I have also read posts that suggest that the ECM needs time to relearn after the battery is disconnected.
Did I damage the ECM and if not how long should I wait to see if the ECM relearns the proper idle speed and given the circumstance does anyone have any suggestions?
I apologize for the wordy post, but I thought the history would help in Dx'ing the problem. Needless to say I also beg your indulgence for any portion of my question that may have resulted from my own ignorance.
Thanks,
This is a test
Tobylima
Thats the Mud welcome by the way!
