1981 XJ-S ECU Repair?

Subject: 1981 XJ-S ECU Repair?

Date: Sat, 15 Feb 1997 21:54:39 +0000

Comments: Authenticated sender is <jnuttall@julian.uwo.ca>

Three months ago I asked the list for suggestions on curing the poor cold start syndrome on Paul's 1981 XJ-S. This is a somewhat uncommon car. It is one of probably only a few hundred pre-HE vehicles to have Digital P Jetronic fuel injection. Apparently this type of car had European specifications and was not sold in the US, but this one ended up in Canada. Thanks to Matthias, Dick, Greg and Michael who responded with suggestions on the cause of Paul's trouble. Paul has now found time to investigate, and it seems that Michael, who suggested a dud ECU, was probably correct. Paul has tried replacing the ECU with one from a 1986 XJ-S HE. The cold start problem goes away but, not surprisingly, the car does not run well in other respects. Paul therefore wants to repair or replace his 1981 ECU. It is possible to buy a new one or get the old one rebuilt, but the expense is significant. Quite possibly only one or two components in the ECU are defective. Is it possible to obtain a circuit diagram and/or other information for the ECU which would enable an electronics technician to diagnose and repair the defective ECU? John Nuttall jnuttall@julian.uwo.ca 1977 XJ-S 1979 XJ-S - parts