Just curious....

[sam_d]

Earlier tonight I suffered what I will call a "automotive motion preventing curiosity" (since it sounds much better than telling people my car "broke down") at Mount Victoria.

For some reason I had little or no electrics and initially I was concerened that something I had done last night while installing a UHF radio had somehow completely shafted the car. However, since the car had worked fine up until the refuel at Mount Victoria on the way back to Sydney I guessed it wasn't.

The problem was that the -ve lead had become detached from the battery. A few seconds with a spanner and I was on my way. Excellent.

Anyways, that's the background, now to the question:

While the battery lead was disconnected would it have reset and electronic engine management?

I am asking because I noticed a significant improvement in my car's performance after the event. It accelerated far better, seems to have drunk less fuel on the last 100km to Sydney, generally sounded better and started without it's usual grumpy attitude.

IF the engne management has been reset, how/why did it come to manage the engine so poorly before?

[DEFENDERZOOK]

its possible a sensor had gone out of range....and the ecu had compensated for it with a preset value......more commonly known as limp mode.......

or....you simply got some decent fuel......a rarity these days......

[dullbird]

limp mode:eek::eek: d1's dont have a limp mode do they thought that was a d2 thing

thought d1 was more like an amputee mode brake it and yeh buggered:D

[DEFENDERZOOK]

limp mode was introduced the same time as ecus.......

[willvine]

I cant be sure but i do remember reading somewere that the engines fuel managemant does get reset after a battery disconect . but i am only guessing

[abaddonxi]

Well it's all downhill from Mount Vic, so it has to go better.

:D:D:D

Cheers
Simon

[Michael2]

It could have been the poor battery connection that contributed to the poor performance (voltage drop across the sensors, ignition and ECU). Tightening the clamp may have been all your car needed.

[sam_d]

Limp mode? I was more like remove both legs and crawl along with broken arms judging by the difference it's made. :)

And I did think that maybe going downhill all the way back to Sydney may help the fuel economy but I was making the most of pulling away at a new found rate at traffic lights and was tonking it along the highway so I wasn't driving particulary fuel efficiently. However, in the morning I was tring to drive as fuel efficiently as possible just to see what mileage I could get.

[sam_d]

Oh, and another thing (thanks to Michael2 for reminding me to ask)...

Does having the battery disconnected once the engine is running make that much of a difference to the other car's electronics bits and bobs?

I was under the impression that once the engine was running it was generating electricity so the battery doesn't neccesarily need to be connected...

[DEFENDERZOOK]

that was in the good ol days.......


on todays cars......disconnecting the battery whilst the engine is running will cause damage to the electricals.......

[wovenrovings]

In a D1 3.5 V8 my family once had we had a lot of trouble getting it started after sitting for a week. This was a repeated problem, checked a lot of things including the battery which checked out ok. It would wind and then actually run backward for a turn or so after letting go of the key. Usually ended with us pushing it down the hill to start it, good thing we lived on a hill. The short of it was we went to sell it and gave it a good was and replaced the battery. Changed the whole car. Started with barely a turn. Ran better too. Specially at idle. Just goes to show what a difference it made.

[PhilipA]

If a 97 D1 has catalytic converters, the disconnect will reset the fuel parameters.
If not it will make no difference as the 14CUX without cats only reads a map of reactions to sensor input.
Regards Philip A