Thread: 3.9 V8 cutting out.

When I first bought my D1 new it used to do that - it was the connector on the MAF - it would momentarily loose connection and the engine would shut down.

Was fixed and then works OK.

Later as the car got older the car had issues starting and that turned out to be issues with the ignition amplifier. Fixed and worked fine.

Later after a service, similar symptoms appeared again and it was the rotor in the dissy - the service agent had used an aftermarket rotor and this had broken down - only OEM Lucas rotors are suitable.

So as you can see from my own experiences the symptoms can result form a few different causes. Easily fixed but hard to diagnose.

Garry

TPS

Bit of additional info I have noticed today.

It mainly does it on light throttle.

IE highway at 100km/h.

When it shuts down it will stay that way unless you mash the throttle to the floor. Great for getting going again, horrible for engine mounts / fuel usage

TPS would explain a few things. but my other thoughts was with the AFM. would the additional pull of air through the AFM from going open throttle make it come good? Doubtful but I'm just thinking out loud.

As there are no moving parts I would rule out air flow meter, apart from what Gary said re connector. The TPS's usually form a dead spot, so you could possibly keep it going if you nail it before everything dies. You could temporarily move the TPS a poofteenth just to work out what's what. If you haven't got a multimeter, then mark it first so you can put it back where it was. It only needs to move a smidge.

Possibly a loose internal wire on the distributor pickup. Applying full throttle moves the pickup a bit and makes the dodgy wire reconnect. Connect the pickup wires to a multimeter, read the resistance and apply vacuum on and off and see if it goes open circuit. Or swap out the dissy.

Double check that all dissy wiring is clean and tight too.

Hope not.
I just replaced the dizzy! and ran new wires from the dizzy to the ignition amp.
Unless the pickup in the new dizzy is faulty :S
But having said that, this issue did happen a few times before the dizzy was replaced.

A faulty TPS can give symptoms of wanting to cut out at lower rpm. D1s also suffered problems with the infamous spyder connection shutting them down completely, but I would imagine these have all been sorted by now (by-passed).

Investing in an ECUMate can be a godsend when it comes to sorting the efi side of things, although it doesn't tell you anything about the ignition side. Best fix for that is a Scorcher - pricey but permanent.

Hmmm Spyder... The immobiliser is still in tact. Well it doesn't start unless i disarm it.
Does the immobiliser play with ignition? I (obviously) know it touches starter and from what i read, fuel.
Might pull it out and reflow all the solder joints anyway to be safe. Had to do that with the window control box.
I won't go as far as a scorcher. I'd rather retro fit a new ecu and have a decent system than do that. I have fitted a brand new dizzy so im pretty confident that it should be ok.
I might try and track down a TPS. Sound logical that it could be at fault here.