2_time_ace

I just replaced the alternator on my 92 SC300 with a Bosch one. After completing the install and checking the connections I started her up. Although it started without incident it stalled out after about 3 seconds. I have repeatedly tried to get it to start and remain running with no success.

After about 7 tries, I disconnected the alternator and cleaned the contacts on the plug connector, again with no success. On a hunch, I left the alternator disconnected and started it up on just the battery. Sure enough it starts and continues to idle fine on just the battery disconnected. Clearly there is something wrong with the alternator connection that is preventing the car from running with it connected. Before I head to my mechanic, I would appreciate any insight anyone might have.

O. L. T.

iTrader: (17)

check all vac lines and the maf connection since you had to remove the intake. Just to be sure.

Sounds like the connections on the alt are backwards if it is a voltage issue. Just a hunch.

2_time_ace

Thanks OLT. I did check the vac and maf and found no problems. I also disconnected the alternator, cleaned the contacts thoroughly and reconnected it. In the process I reoriented the battery wire connection off the top post of the alternator just to make sure it wasn't grounding out somehow. Immediately after taking these measures she started up and ran without incident.

Thanks again!

CantSeeMe

2 time ,You can make the check payable to O.L.T.

2_time_ace

Despite my earlier reported success in resolving the symptoms by reconnecting the alternator, the problem resurfaced just two days later as I was picking my car up from my mechanic (fortunately). He undertook tracing the problem. He was able to determine that the fuel pump was losing power immediately after the key was released and the starter disengaged. The problem was traced to the Fuel Control Module. Replacement of the FCM corrected the problem and the car has been running great for more than a week now.

A new FCM from Lexus is ~$300 but he obtained a used one for $125.

One note to those experiencing the problem: the service manual notes that the FCM is located in the drivers side rear quarter panel but in fact it can only be accessed via the trim panel in the passenger compartment back seat and requires removal of the driver's seat, the back seat and the trim panel.

Hope this info helps!