So, this just happened. Damned electricals...

Hmmmm... Mulling it over....

 

As I said earlier, initially I was convinced that it was ignition/electrics related but the video shows a classic running out of fuel symptom. Not to say it's not electrical...I once worked on a car where the coil was defective, misfiring under load when aggressively turning to the left. Otherwise, it ran fine!

Re that - I don't know how it would be done on these cars but is there any way to check the Digiplex for proper operation? I have seen defective ECUs do decidedly weird stuff and the only fix for a bad one is replacement. Frankly, considering all the work you have done with little/no improvement, my eye would be moving toward that ECU.

 

It could still be the alternator which is failing when it gets hot. Put a multimeter onto the power to the coil and watch the DC voltage when it dies. Also check for AC in case a diode is failing when hot.

 

Also feel how hot the fuel pump is when it dies... does it improve if you cool the pump with compressed air, damp cloth etc.?

 

But if the battery can then immediately spin the starter, there is plenty of power to operate the ignition system...at least until the battery runs down. You can disconnect the alternator and the car will run for many miles on just the battery. My most recent alternator failure (not Ferrari) occurred 40+ miles from home and the car made it home on the battery with no trouble at all...

 

Mike, the alternator could suddenly increase or decrease the voltage or give a pulsed half wave or AC that could affect the ignition system (but would not affect the battery’s capacity to start the car.)

 

It's running an aftermarket ecu for ignition, if the starter is spinning, then the ecu has power. The electromotive unit needs 10-12vdc and less then 1amp to run. Coils pull more, but nothing like the starter.

 

I REALLY have converted myself to believe it's a fuel issue...

In any case, it will be great to find out! Hope that's soon and without additional expense!!

 

Can you easily put another ignition system in? It could be the Electromotive system failing when hot? Or a coil going bad.

 

I would do the easy things first-- starter spray to rule out fuel issues and timing light in the cockpit to confirm it's ignition. If you know the output specs of the sensor for the XDI? You may be able to see the pulse with a multimeter.

 

Have not followed the entire thread. However have you checked the connectors behind the fuse block - and the ones under the passenger floor? the Fuse for the fuel pump circuit gets really hot in 308's ... I wonder if your connectors are burned out or burning out? also there is a protection relay in the right rear trunk - that could also be corroded - loose etc. with full power coming through the charging system ... you could be providing more power than it was used to... lots of resistance. .... my old 308 had tons of those issues.

 

I saw your video. If you have not tried this - give it a shot. Under the antenna pull up the carpet. under that you'll see a plate with 4 bolts - remove the plate. check that the relay's fuse is good - also check that all wires and connectors are tight dry and not corroded.

then check all your aux air hoses from the Auxillary air valve to the intake - I can't remember where they are on the QV - but a pinhole in these can cause havoc - as they expand & contract. but usually don't cause the car to stall... the only other thing that comes to mind is the under the idle mixture screw there is a small rubber grommet.. mine had deteriorated over time causing a huge air leak,... which gave lots of running problems. as it warmed up the car would die at idle... but I'm thinking that you have a bad connector in the trunk area. the one on the driver's side is the Digiplex... doubt that is a cause - but could be.

 

Fuel filter.... Very likely not.. They are metric straight threads and bubble fittings... Nothing adapts to them. They look AN but are very much not. You'll need the right filter, shouldn't be hard to get.
When I update the CIS to EFI I get adapter fittings for metric to AN and ditch all the factory tubes that use the goofy bosch fittings, it's intentional on bosch's part and makes sense, just a pita these days as CIS is obsolete. Filter is not Ferrari unique, VW or mercedes, saab, volvo.. Etc.. though more often then not it's shared with mercedes.

Pick-up resister isn't strictly needed but does help with SNR at rpms over ~6k. EMI is high from the plug wires. (Capacitative coupling)

 

I know of Walbro pumps for over 20 years, it has long been popular as an aftermarket upgrade fuel pump in the Miata world when adding power (turbo, supercharger, etc). Decent quality and reliable... but not what I'd necessarily put in a 308, either!

 

CIS requires not only flow but pressures far greater then most EFI pumps. EFI pumps do not work for CIS systems.

 

Go get the wife's hair dryer and heat up the mag sensor while your car is idling. See if it stalls once you get it hot.

Aaron

 

Good progress. A lot of us are cheering for you!

 

Asking the obvious, did you add the 5V for the Hall sensor? Did you get it from pin 19 on the XDI unit? I've read through all the XDI docs at least twice in the past week, but now that you mention it I went back and couldn't find the note I was sure I read about the Hall being a direct substitute once it had 5V.

I'm getting ready to install my XDI finally, 2 years after I bought it from Nick's, and got curious about the Hall sensor after reading Scott comment at least twice that he disliked the mag sensor and preferred the Hall sensor. (Which Hall sensor, the Electromotive unit?) What resistor are you adding and why? The Electromotive online store entry for their Hall sensor says it includes a pull-up resistor so no additional resistor is needed.

Very interested in hearing what Electromotive says!

Gordon

 

I just had the same problem, that white plastic vertical connector was bad, it turned brown as well, my symptoms were that the car would fail to start intermittently . then it failed for good. I thought it was the fuel pump relay, because it was making a very bad buzzing sound, I replaced it, and it did not solve the problem, my mechanic found the vertical connector to be the culprit. Im not sure this helps Thorn.

Thank you