[Frog and Ogy]

Hi all-

Well advice needed please-
I’ve had my 92 420 SLI off the road since Feb, parked up at my Mums... now She’s been regularly started- the 420, not my Mum!) and has stared and run well on tickover.

Went to drive Her back for an MOT, put a couple of gallons on fresh fuel in, and found that She won’t pull above 2000 rpm- in fact the engine seems to die back as soon as it get near those revs, She would kangaroo incredibly badly, and shake violently, and only by feathering the throttle and clutch and getting her into high gears ASAP and below 2000 rpm I could just about drive her- thank goodness the M series has a lot of low down pull.

She ticks over fine, and when stationary, if you operate the throttle by hand in the engine bay, She will rev quite happily- She just won’t take any load.

She has always run on the cool side- the thermostat is due a change, really. There are no signs of overheating at all.

Before the lay up She was a terrific runner, started first time and went well and, ahem, quite rapidly..

Managed to get her to our long term, trusted garage- who are sympathetic to older cars, and they’ve changed the plugs, but to no avail, and bemoan the fact there isn’t any diagnostic socket or access...

So... good people, any ideas? Is there any diagnostic facility- either one I can obtain myself or at least provide to the garage ?-I seem to remember that on the Rover SD1 EFI’s there was a simple diagnostic system, for plug in...

Any advice gratefully received - I really want to get Her back on the road....

Cheers
Mark

[GTiJohn]

Have a look around where the battery is under the bonnet as there should be a 3 pin connector around there. It should have a coloured cap on it.

If it does, you might be in luck, as the club has just purchased a Crypton ACT3 diagnostic bit of kit that can run checks on these. We proved it worked by hooking it up to a 220 Turbo and it said there was a problem with the coolant sensor. Looking at it the wiring did look a bit dodgy so it seems to be working.

We haven't worked out how to fully utilise it and how members can benefit from it yet but we might be able to follow the lead of the RCOC and offer diagnosis sessions at shows.

[RoverRevival]

e5 or e10 fuel?

Most of my cars run like on e10. Could be as simple as that

[Roverlike]

If he has 3pin connector under bonnet, then PScan can also be used.

[Frog and Ogy]

Thank you for the responses, Guys, She does have the 3 pin diagnostic socket - now is there anyway that the club diagnostic could be “ hired”?

The strange thing is, I brought Her back from the garage last Wednesday, and initially She ran perfectly !! - for about about 5 minutes, pulling like a train,- I thought Bloody Hell! - result....

... however then, after waiting at some roadworks lights a mile or so up road, and then pulling away She reverted to “dying” as soon as the revs hit 2000rpm, and as I said before as there’s plenty of torque I could get Her into top quickly and 1750rpm equates to 40mph- so She was drivable.

As I said She starts first time, ticks over great, runs to up to temp ( gauge sits just below half - and the fan kicks in when it reaches half way) and pulls fine but only up to 2000 rpm.

I’ve got to fix Her ASAP as I’m moving to Norfolk, from Reigate on the 23rd of Sept and want to get her MOT’d ...

[RoverRevival]

id suspect and earthing issue, slam panel or gearbox without seeing it.

[GTiJohn]

Thank you for the responses, Guys, She does have the 3 pin diagnostic socket - now is there anyway that the club diagnostic could be “ hired”?

The strange thing is, I brought Her back from the garage last Wednesday, and initially She ran perfectly !! - for about about 5 minutes, pulling like a train,- I thought Bloody Hell! - result....

... however then, after waiting at some roadworks lights a mile or so up road, and then pulling away She reverted to “dying” as soon as the revs hit 2000rpm, and as I said before as there’s plenty of torque I could get Her into top quickly and 1750rpm equates to 40mph- so She was drivable.

As I said She starts first time, ticks over great, runs to up to temp ( gauge sits just below half - and the fan kicks in when it reaches half way) and pulls fine but only up to 2000 rpm.

I’ve got to fix Her ASAP as I’m moving to Norfolk, from Reigate on the 23rd of Sept and want to get her MOT’d ...

Sounds like something is going as it astray as it warms up. The disagnostics may help find out what but we have to work how to use it first

[Paul_1978_yorks]

Could need the fuel tank draining and fresh fuel, especially if it has been stood and the fuel has gone stale. A few shots of Redex over a few weeks might help too.

[220 GSi turbo]

Have you tried a new rotor arm?

These often break down as the engine gets hot. Relatively quick and cheap fix, although try to avoid buying an 'Intermotor' branded one if you can!