Cutting out when coasting

Has anyone heard or experienced issues with the engine cutting out, or cutting to tickover when coasting/almost off the throttle?

It's an issue I'm having great difficulty replicating, but when releasing the throttle to near nothing it just completely goes in to full engine braking, I can't tell if its still running or if its died completely, I suspect its gone altogether.

(I'm slowing down, but not off the throttle completely, just changing speed from 50 to 40 slowly?)

I'm unsure where to start since its so hard to replicate, I thought I'd start by checking the butterfly in the throttle body is tight but beyond that I don't know how the G13 engine decides how much to inject, I'm leaning towards either a faulty MAP sensor or something amiss with the fuel pressure/return. I would guess if it's the MAP it would cut to tickover and not completely. I don't know if the IAC could interfere here, it does seem to behave a little odd in the morning, the revs go up fine in a morning but keeps going up while I'm driving for a few minutes, I get to a junction and dip the clutch and the engines over 2000rpm but then starts slowly dropping.

So basically, I have no idea

Worth noting, I don't have OBDII so I can't plug in and review data for common sense readings. No error or MIL (if it even has a function to do this?!)

It does have the ability to store codes but if the CEL isn't on then its unlikely to have any. The Idle Speed Controller is used to give a 'dashpot' effect when slowing down so I would start by checking that is working correctly. Do you have any other symptoms? what is your idle speed like?

No other symptoms, fuel economy seems to be ball park.

It starts 1st time every time revs to just over 1000rpm cold, and settles just under when warm - it does as I say seem to raise the revs when I start driving from cold and I only realise when I come off the throttle and not much happens, I just assumed this was fairly normal for an early EFI like this but I don't know, I don't really do electrics I just try to play over the symptoms and rolls of each component and what effect things might have - slightly educated stabbing in the dark really.

Russ-41 wrote: I just assumed this was fairly normal for an early EFI like this

Its not that early, its actually a very sophisticated unit.

I thought they died completely on full overrun (throttle pedal up, speed above idle and maximum manifold depression), as the EFI simply stops injecting, so you would see 9999 on your MPG gauge.

Sitck your foot on the clutch, or knock it out of gear and it just runs at tickover.



My olden days Maestro used to vent the carb float chamber to manifold on overrun, to cut the fuel off, but it had to keep tickling fuel through as the inlet manifold walls needed to be wet with fuel so there was some throttle response when you went back on the pedal.

The injectors are right by the valves, so there would be no need for this.