4jg2 1996 Bighorn intermittent rough running

[Plaisir]

A friend of mine has a 1996 jap auto Bighorn and has the following problem; It started to hunt at idle a few months ago, this has now developed into the current condition.
on starting the engine hot or cold it wants to stop however if you catch it in time you can rev it giving some smoothness, the rev counter indicates zero and the engine warning light illuminates.
the engine can stop altogether when reducing speed in drive for cornering etc, losing power steering, keeps the blood pumping. Other times it can behave as normal.
between us we have 3 roadworthy Isuzu's and two others as parts. To date the accelerator peddle assy.including senders has been changed and the rack of relays near the brake servo/booster.
The relays were replaced following when the engine couldn't be started occasionally, this eliminated that fault. It may be a dry joint somewhere confusing the computer?
Any ideas as to what may be causing this would be greatly appreciated.
Thanks Grant

[geeves]

sounds like the governer in the electronic injector pump

[Plaisir]

Thanks for your reply, on inspection of the injector pump a lose wire was discovered leading to what looks like a chip (has 951 no7 on it)
Looks like someone has been playing with it as there were two connectors there maybe they had changed to another unit?
Re connected and all is good.
Thanks for your tip!
Grant