Engine Stalls

[Joe Tracker]

ok ,knife edge stalls, right foot, cannot save it.
and is not the maf the tests are ok

id say spark ends, is the cause.
ECU fuses bad, rusty or with internal cracks,
if the ECU looses power, even the CEL goes dead,
as the engine stalls ,
the tacho will go dead,from say 800 to 0rpm
then the cEL must come on, does it, if not, the ECU just lost power
if the pump lost power the RPMs fall slower, and right foot can help here,
the knife edge stalls are: (LIKE A CLIFF FALL)
lost power to ECU, the scan tool goes dead at the same time, connected at the time it stalls
if the distributor fails. if the scan tool is connected, and CEL comes on, at stall, guess what, you see CKP, CMP or spark lost DtC ERRORS.
LET IT STALL ,DO NOT TURN OFF THE KEY, SEE THE ECU TELL YOU WHY IT STALLED. (all but fuel pressure can be reported, let it)

BELOW 200 RPM The ecu thinks engine is dead, then turn on the CEL, NOW ,AND FOR SURE 0 RPM
You can push start this car, keyon ,CEL on
or graVITY START, ON A hill, dumping clutch in 2nd ,gear, key on ,CEL on;

you are losing spark, (random)
are all engine grounds good? under the hood, there are many, and any found loose are bad news for EFI.

owning a scan tool makes diagnosis more easy
ecu lost comms
ECU shows errors, at stall.
ECU CEL DEAD AT END OF STALL.
P03XX Errors.

ours has FI fuse, IG-coil fuse and the dome fuse for ecu memory
not sure on 99. names of fuse.
fuses can have hair line cracks, and are a horror if true.

OK. I will:

1. Check all the grounds in the engine compartment.
2. Find and check the ECU ground.
3. Check and possibly replace any fuses related to the ECU or combustion management process.

Also - I discovered some wires going to the O2 sensors that may have grounded out. The PO had the O2 sensor replaced - now nearly three years ago. They routed the O2 cable through a lifting eye mounted on the left rear of the engine, but they did not wrap or protect the wires from chafing on the eye. At least two of the wires then chafed and wore through the insulation and exposed the cores. They may have intermittenty grounded out on the lifting eye. I have since re-insulated them with electrical tape (and will put a cable guard on later). But that did not fix anything - the car had the same knife edge stalling issue when I next tested it. I do not know if this relevant, but now you know.

Thanks,

Joe Tracker