low idle and it died

[lovemysan]

Last night I was EOC'ing to church. 3 minutes from the building I do a bump start and the engine is sluggish to respond. Its also idling at 300-500 rpms. I drive a mile under power and it dies at the next stoplight. So I decide I'll run it hard a little and shift around 4k. It didn't help, it died again in the parking lot. It drove normally home after services.

Any ideas?

[onegammyleg]

Need more info

[lovemysan]

its happened twice. Once dry and once wet. Once with cold engine and once with Normal temp. Once after a 20 minute drive and once minutes after leaving the house. Once at night and Once during day. Both times while EOC'ing. Both times seem to go away after a short rest. What happens is after an EOC I'll restart and it won't idle normal RPMS. Its a constant just under 500rpm. Last night with lights, defrost, radio, and wipers on it died out a couple of times. I think it might be a soft battery or alternator.

[GasSavers_Brock]

I was going to say, can you get a meter on your battery? I bet the alternator si putting out enough power to keep up with the laods and might be casues the car to stall. Did it turn over ok or did you bump it to start it again?

My second guess would be sort of flooding due to low rpm, but if it has not done that in the past it might not be as likely.

[JanGeo]

Are you EOC with the ignition on or off?? could be the ECU is not liking the bump start or is doing something weird when moving with the engine off. Next thing to do is to check the tail pipe and see what sort of fumes are coming out - rich or lean smelling or liquid fuel. Also try cycling the ignition off and on again when moving in gear so the engine never stops turning and see if that clears it up right away.

[onegammyleg]

I dont think the programmers took into account EOC driving habbits.

Not saying this is the fault in your case , but If you can imagine if your key is in ?run? position the computer is getting inputs from various sensors saying normal (temperatures etc) , zero for intake pressures , O2 would be just off normal but dropping and a quite unexpected high input from the speed sensor.

If I was a computer ide be prety pee'd off with that !.

[cfg83]

onegammyleg -

Originally Posted by onegammyleg

I dont think the programmers took into account EOC driving habbits.

Not saying this is the fault in your case , but If you can imagine if your key is in ¨run¨ position the computer is getting inputs from various sensors saying normal (temperatures etc) , zero for intake pressures , O2 would be just off normal but dropping and a quite unexpected high input from the speed sensor.

If I was a computer ide be prety pee'd off with that !.

... computer-man image ...

I agree. Here's an idea on how to attempt to deal with this. Get a battery switch in order to strategically reset the ECU once per day or once per "interval X". These are what I think would be the benefits :

- You could rely on the ECU to "behave the same" all the time. That way, you could tailor your driving style to "reliable" ECU behavior.

Here are the problems :

- The initial state may not be optimum. Since the ECU needs to learn, it may be using too much fuel in it's early learning phase to get optimum MPG. This is a trial and error proposition.

- You will always be losing your presets. Losing the clock is no biggie because you can always buy a battery operated one. I can't do anything about the radio station presets. However, this problem could be negated by figuring out how the ECU is being powered and making a power cutoff switch there. That way, you wouldn't need a battery switch. But the car would have no brain, so to speak ....... Hmmmm, what would the car do when you turned on the ignition when the car didn't have a brain? Is this a Tin Man question, or a Matt Timion question?

CarloSW2

[lovemysan]

Originally Posted by JanGeo

Are you EOC with the ignition on or off?? could be the ECU is not liking the bump start or is doing something weird when moving with the engine off. Next thing to do is to check the tail pipe and see what sort of fumes are coming out - rich or lean smelling or liquid fuel. Also try cycling the ignition off and on again when moving in gear so the engine never stops turning and see if that clears it up right away.

I'm keying off the car and turning back on so mileage with compute. I bump start 50% of the time.

" I dont think the programmers took into account EOC driving habbits.

Not saying this is the fault in your case , but If you can imagine if your key is in ?run? position the computer is getting inputs from various sensors saying normal (temperatures etc) , zero for intake pressures , O2 would be just off normal but dropping and a quite unexpected high input from the speed sensor.

If I was a computer ide be prety pee'd off with that !."

The ECU should adjust to this just fine. Consider that the Cam or crank sensor is returning a value of zero. So the ECU knows the engine is not running. It may not like the accelerate and then key off. Thats something I'll monitor in future.

I was hopeing diamond larry would have some input.

[JanGeo]

I'm just thinking that the ECU may go into some safe mode when the key is left on and the car is moving but the engine is not running it may think something is not right with the sensors indicating engine function. You could be stopping in a certain position only once in a great while that triggers some safety mode. Sometimes designs don't take into account long term improper operation like leaving the key on without starting the engine.

[onegammyleg]

Originally Posted by JanGeo

I'm just thinking that the ECU may go into some safe mode when the key is left on and the car is moving but the engine is not running it may think something is not right with the sensors indicating engine function. You could be stopping in a certain position only once in a great while that triggers some safety mode. Sometimes designs don't take into account long term improper operation like leaving the key on without starting the engine.

Didnt I just say that