3.9 Hotwire on 3.5

Hello all!

I have a defender 90 with a rover v8 3.5 with 3.9 hotwire fitted as the flapper was useless!

I need some advice, there is a lack of power in fourth and fifth gear (has a 1.4 transfer box fitted and 35 inch tyres) also after the car has been driven got up to temperature when the engine is turned off it will not restart after for a few minutes!

Has anyone had any of theseproblems before or any advice?

Perhaps look at the 3.5 Hotwire system and see if there's any difference to the 3.9s a different ecu I expect for a start.

Me and a mate put hotwire on my 3.5 flapper RR. Same ECU for all as far as I know, you fit the relevant tune resistor in the loom so it knows what it's running. My vehicle is a 3.5 non-cat so I fitted the tune resistor for a 3.5 no-cat disco, closest option. Mate also cobbled together a micro switch system around the auto gear stick so the ECU knows when the car is in drive/reverse or park/neutral. He also made up a speed sensor that works off the front prop bolts, the ECU then knows when the vehicle is moving, although I don't think it actually matters once you get over 5mph or something. Basically we wanted to give the ECU as many inputs as possible. We could see it all working through the laptop then with whichever program it is (rovergauge?). Mine now runs fine (especially compared to flapper!), but ultimately I'd like to go to megasquirt.

Good luck with yours.