Thread: Stalling when hot & poor fuel economy

Undo the vacuum hose at the fuel pressure regulator (rear of the motor) and look for signs of fuel leaking into the engine via the vacuum hose. Stuffed regulators are not uncommon.

Check the ignition timing with a timing light, make sure both vacuum and centrifugal advance are working. Set the timing at 8-10 degrees BTDC at idle.

Stepper motors can be cleaner with carby or throttle body cleaner. You can also raise the base idle speed with a 3/16" allen key inserted in the small pocket on to of the throttle body.

Absolutely...start by cleaning the stepper, I followed bee utey's advice before, I cleaned my stepper on the side of the road in angst with nothing more than wd40 and a baby wipe! Instant success now my fuel economy is looking better too. My idle is much lower (550 rpm) but there's no hunting surge or stalling and I'm feeling better about owning my disco. It is easy to clean providing that it is dirty and not buggered and can offer step by step detail if you want.

Kind of dove in and pulled the stepper out. However, I pulled the whole body off the manifold (three screws with allen key heads). Cleaned inside that with carby/tb cleaner. Not sure if that is thorough enough, or should I pull the actual stepper itself out? I drove around for 5 minutes and no stall, but the problem isn't always there. If it comes back I guess I'll take the stepper itself out.

What about cleaning the MAF?

Not sure if that is thorough enough, or should I pull the actual stepper itself
out? I drove around for 5 minutes and no stall, but the problem isn't always
there. If it comes back I guess I'll take the stepper itself out.

Yes undo the big nut on the stepper itself and clean the "cone" and use a cotton bud on the seat also.
DO NOT try to unscrew, pull or otherwise move the stepper cone on the stepper itself as here lies heartbreak.
Regards Philip A
jeez I am getting old. I forgot to say that you should also take the rubber hose off the throttle body and clean the butterfly and all around it. Also seeing you now have bits off its a good time if teh engine is warm to block off the stub and hose to the stepper and set the base idle at about 550 -600 RPM by turning teh allen screw on top, out is faster .

Check the resistance on the thermocouple (engine water temp) that feeds the ecu, it's located near the thermostat.

If this is sensing a colder water temp, it will think it's running cold and continually over inject (run a different fuel map) make it run richer.

Spray all the air supply hoses with wd40 that fed the plenum, you might have an air leak, if there's a leak the revs pick up. also pull the flame trap of the rocker cover, place in a jam jar with white spirt and give it a good flush too.

Check that the hose from the rocker cover to the clean side of the air filter is all good too.

Check the plug connection on the MAF.It still gives me grief on the odd occasion.Just by unplugging it and plugging it back in the idle will go from "Top fueler" to smooth again.
I chased idle problems for ages till I found this problem.
One day I will get around to fixing it properly.........