Thread: 3.5 hesitates at higher revs

I would check your vacuum advance, suck on it to see if diaphram is holding suction, then also make sure your mechanical advance is working. Also Put a timing light on it and see if timing is out.
Check other vacuum hose for splits

oh well checked the timing and vac advance all good have also swapped from my other disco the plugs leads cap and coil
maybe its fuel if i hold the throttle around 4000 rpm you can hear a popping out the exhaust as if its struggling for fuel

Hi the modern ulp doesn't last long theses days. I wouldn't do anything till you can give it a drink of fresh fuel, I only use premium, and my timing is now 10deg, BTDC heaps better ...Gary

Originally Posted by Gary S11

Hi the modern ulp doesn't last long theses days. I wouldn't do anything till you can give it a drink of fresh fuel, I only use premium, and my timing is now 10deg, BTDC heaps better ...Gary

thanks gary i was thinking of draining the tank i will try some fresh fuel clean fuel filter and some injector cleaner

I had a '92 3.5L V8 that used to miss. Typically did this after going up long hills with the right foot planted & miss usually occurred when dropped from 5th back to 4th gear. I thought it was a fuel issue, but Land Rover mechanic advised me it was a well problem with the valve guide material. once heated up the valves would want to stick in the guides apparently.

Try some upper cylinder lubricant in fuel & see if that makes any difference. The repair for new valve guides cost me a fortune & in hindsight I'd keep buying upper cyl lube if that fixes it.

I also had a similar problem with my '91 3.5. Landrover mechanic tried to convince me it was valves sticking then decided it must be ignition and changed the ignition system. Turned out to be an ECU problem. I swapped the ECU with a second hand one from ebay and solved the problem. Mixture was going way too lean at higher revs under load.

thanks for the advise i have a 93 disco as a parts car hopefully the ecu is the same as i have noticed a few minor changes on the electrics between the 2 cars such as the dizzy amplifier where would i find the ecu on mine ?
thanks

justin