Re-start Trouble after cold stall

[DPDISXR4Ti]

My wife has had this happen a couple times now, as she struggles to drive a manual transmission vehicle again for the first time in 20 years. Engine starts fine (dead cold), but shortly after starting she manages to stall it. Tries to re-start and it cranks over fine but doesn't re-start. Fortunately she was only 5 miles away yesterday when this happened, so I drove over and verified the problem. As it cranked, I quickly applied some throttle and it started right up and drove home fine. My working premise is that it was flooded and opening up the throttle leaned it out enough to start.

I'll pull codes again, but any best guesses? I'm pretty sure the MAP, ECT, and TPS were all semi-recently replaced by Darren.

[Ed Lijewski]

(Flooded? Did she drive into the pool?)

My two Scorps fire up instantly dead cold. After shut down restarts often are labored-but not always-and depressing the accelerator typically gets them to fire up. Never could track down the cause, but I suspect possibly injector(s) leaking.

YMMV

[DPDISXR4Ti]

My two Scorps fire up instantly dead cold.

Same here. Dead cold start-up is never a problem. I tried to recreate the symptom today by shutting down 5 seconds after dead cold start and re-starting - no issue, started right back up. I'm thinking that in a stall condition some extra fuel may get dumped in vs. a purposeful shut-off. Fuel injector replacement is on my to-do list. It just leap-frogged a few items on said list.

[brokencase]

Sometimes when it is damp and foggy out it will not start on the first try, condensation on the distributor cap I suppose. An inpatient driver might start pumping the pedal and may flood it. Holding the pedal down and cranking will usually resolve it. YMMV..

[John Brennan]

... An inpatient driver might start pumping the pedal and may flood it...

Is that even possible with these cars and their dry intakes? I'm not so sure...

[Ed Lijewski]

The ECU reading the TPS, on the last pump(s) if the starter is turning-could add more fuel.

YMMV

[brokencase]

I've had mine flood before. Its not like an accelerator pump, but if it's damp and the mixture doesn't fire at a part throttle setting then it will just keep firing the injectors. The plugs get wet and then the situation gets only worse. As we should all know - pushing the pedal all the way down during starting will cause the ECCIV to stop firing the injectors (and keep firing the plugs).

[DPDISXR4Ti]

As we should all know - pushing the pedal all the way down during starting will cause the ECCIV to stop firing the injectors (and keep firing the plugs).

In theory right, I'm just hesitant to use that approach and it's not working as it should and you've got a whole lot of throttle going on when it starts. Have you ever actually tried it? I've only ever done it when doing a compression test and I've already killed spark, so no chance of the engine starting any way (just don't want the fuel washing down the cylinder walls.)

[DPDISXR4Ti]

Is that even possible with these cars and their dry intakes? I'm not so sure...

Not sure what you mean by this John.

[Ed Lijewski]

As we should all know - pushing the pedal all the way down during starting will cause the ECCIV to stop firing the injectors (and keep firing the plugs).

In theory right, I'm just hesitant to use that approach and it's not working as it should and you've got a whole lot of throttle going on when it starts. Ever you ever actually tried it? I've only ever done it when doing a compression test and I've already killed spark, so no chance of the engine starting any way (just don't want the fuel washing down the cylinder walls.)

When the syndrome occurs I usually crank the engine without touching the accelerator for ~2/3 seconds and then depress the pedal ~1/4 and the injun then fires if also sputtering briefly.

YMMV

[John Brennan]

Is that even possible with these cars and their dry intakes? I'm not so sure...

Not sure what you mean by this John.

Flooding your intake by pumping the gas pedal in the old, carbureted engine manner.

[DPDISXR4Ti]

Flooding your intake by pumping the gas pedal in the old, carbureted engine manner.

Okay. What I'm saying is that with a fuel-injected engine the opposite is somewhat true. By depressing the accelerator while attempting start, you're actually leaning things out a bit by getting some more air into the engine. Ed's experience above confirms this as well.

[Ed Lijewski]

My wife has had this happen a couple times now, as she struggles to drive a manual transmission vehicle again for the first time in 20 years. Engine starts fine (dead cold), but shortly after starting she manages to stall it. Tries to re-start and it cranks over fine but doesn't re-start. Fortunately she was only 5 miles away yesterday when this happened, so I drove over and verified the problem. As it cranked, I quickly applied some throttle and it started right up and drove home fine. My working premise is that it was flooded and opening up the throttle leaned it out enough to start.

I'll pull codes again, but any best guesses? I'm pretty sure the MAP, ECT, and TPS were all semi-recently replaced by Darren.

I recently installed a new IAC chasing a cold idle hiccup at 1/4 throttle while moving out traffic in cold temps. The new IAC ameliorated that syndrome substantially, and also a bit to my surprise the hot engine now seems to always fire with just turning the ignition key whereas before occasionally it needed the throttle plate to be opened a bit to catch.

I have ~8 used IACs all of which tested fine per the Scorpio and XR Manual as did the IAC I just replaced. And each unit was thoroughly cleaned internally by disassembly. So I didn't think the cold engine hiccup or/and the warm engine reluctance to fire occasionally without opening the throttle plate slightly via the accelerator pedal were IAC related. But thinking about all these syndromes for some time I decided to see if they would diminish or even vanish with a new IAC installed.

So it seems the SM's test re IACs isn't definitive for some driveability issues on our +32/33 y/o vehicles.

YMMV

[brokencase]

Agree Ed, I could see nothing wrong with my my original IAC when I was having the "off idle stumble" issue. If I were to speculate then I would say that maybe there was some sort of small leak occurring past the plunger seal, either the rubber had hardened over time or there was some sort of small corrosion on the seat.

The new one resolved it, but the only question that remains is "How long will the aftermarket units last?"

So far mine has been working fine.

[Ed Lijewski]

The pintle seats on metal. I've also carefully cleaned both pintle and seat of every IAC I cleaned (besides spraying brake cleaner liberally, using a needle nose locking pliers I work the pintles up/down and left/right several times). I replace the O-rings on every cleaning.

So mechanically those parts should work fine.

For me that points to an issue/weakness internally with the solenoid motors, which for me always pass the S.M. test--which unfortunately and understandably is a static, not operating, test.

YMMV