ECU differences

Lasse Kristensen · Post by **Lasse Kristensen** » Sun Oct 30, 2011 10:03 pm

Hello.
My 92' Range Rover 3,9 Efi has been grounden for a while, due to a defect ECU. It doesn't respond to RPM signal and the local electronics repair shop was unable to fix it.
I've found a used replacement ECU, but - my box (1992 3,9 Efi catalyst 14CUX/hotwire) has the seriesnr. PRC9061 and 80274A, the other ECU I've found is a 1991 PRC8702 and 80200A. Apparently this box is later replaced by my box, according to this link :
http://www.lrseries.com/shop/product/li ... C9061.html
My question : Can I use the older box I've found?
Thanks for your help.

daxtojeiro · Post by **daxtojeiro** » Tue Nov 01, 2011 7:11 am

Hi,
you really need to speak to Bltz Racing over on the PH forum, I dont know if he is on here, but he is the Lucas ECU expert, unless someone here knows,
Phil

Lasse Kristensen · Post by **Lasse Kristensen** » Thu Nov 03, 2011 5:22 pm

Hello.
What forum is that?
I installed the new used box, after checking all earth connections.
The battery seems to be defect, although I tried to charge it several hours. It read 12,52V between the terminals, but when I turned on the ignition, the fuel pump relay still didn't click on. I tried to turn the engine, but due to lack of batterypower, the starter just clicked.
When I've installed a new battery I'll make one more attempt, but I fear that the "new" box have been fried, hence it didn't turn on the fuel pump relay

.
Anybody know the voltage I should read on the RPM signal input at the ECU connector? Perhaps the voltage is too high, causing the coil to fry the ECU?