I am second owner of this car, now 126K, which I purchased 10 yrs ago at 42K. My daughter has been driving it exclusively for the past 6 months. Taking the day off work today, I volunteered to drop her off at work so I'd have the car to take a "look see" under the hood....and oh, what I found....
The car starts but does not want to stay running upon "start", except when accelerated 500 to 1K rpm. Then I noticed the dash lights stay dimly lit, and the SRS lights stays on, then goes off. When I got home I checked for diagnostic codes and found "1-2-1", "fault for signal in air mass meter", but the check engine light does not stay "on". I cleared the code. I pulled the AMM and found oil, black flakes and some sludge in the air ducts. I removed and cleaned the ducts, wiped the AMM (careful not to touch the wires) and the intake throat of the throttle body. Also replaced the flame trap (completely blocked - - must have been the culprit)new air filter, distributor cap and rotor.
Went to start the car and found it would hardly crank. Found one cell in the 6 yr old battery was dry. Topped it off, put it on the charger for 90 minutes. The car started right up, but now the dash lights all stay half-lit. You can see them shine in the garage, but not in direct sunlight. Owners manual states when the "alternator" light (battery icon) is on, it means it is failing to charge (hence the low-charge battery?), and the other lights will also stay on because of "the design of the system". Checked and found code "1-2-1" again. The SRS light goes out in time. However, when I accelerate the car, the dash lights go out and stay out. This is probably why my daughter never altered me to the symptoms.
1) Do I need to replace the alternator, or just a component (brushes, built-in voltage regulator)??
2) I have a working spare (80's 240) alternator but how can I tell if it will fit and work properly in a 1990?
3) Does the recurrent 1-2-1 code mean the AMM is toasted? I just had a new one installed in 2003!
4) Could the blocked flame trap have polluted and destroyrd the AMM?
5) Does the dry cell in the battery mean I need a new one?
6) Why does the SRS light come on? Does that system now need attention too or is it the result of the alternator issue?
Any advise on any of these issues is appreciated.
I'll be out of town until Sunday and will read/respond to everyone's input upon my return. I advised my daughter that the car should not be driven in the meantime. My kids brag that I can take anything and "fix" it, completely beyond repair!! I'm just tryin' to keep the fleet running!
Thanks again.
Marc
'78 245 267K (with it's own issues posted separately)
'87 240 5-spd 130K
'90 240 126K