Starting Time...

[Hog]

Originally Posted by Hib Halverson

Depends on what you mean by "power down".

If you mean, turn off the ignition, the answer is "Yes." for short term trim (ie: integrator) and "No." for long term trim (ie: block learn).

If you mean, turn off the ignition and disconnect the battery for at least 15 seconds, then yes, you loose all fuel trim information and you start from zero for both STFT and LTFT.

Also, just so we're all on the "same page", the above is true for all ZR-1s and any GM vehicle from 81-95.

Since powering down the ECM involves disconnecting its power source, AKA disconnecting the battery, that's what I was asking/pointing out. I was specifically quoting a post that said that powering down the car had no issues or something to that effect, and had pictures of a sidepost battery disconnect appliance.

[Hog]

Originally Posted by Hib Halverson

If you have leakage somewhere in the fuel system or the period of non-operation has been long enough for the fuel pressure to slowly bleed off, the answer would be "Yes".

I was asking about a specific car.

[Hog]

Originally Posted by Hib Halverson

LT5 was the first GM engine with SEFI. The next one didn't come along until 1994 when increasingly stringent exhaust emissions standards had GM making the LT1 an SEFI engine. In four years, technology advanced such that SEFI LT1s didn't need the long crank time.

.

There are GM engines which were SFI before the LT5, the 1984+ Grand Nationals with the 3.8 were all SFI engine with the wasted spark ignition system. Similar in appearance to the LT5 and Northstar ignition hardware.
The Buicks were known to have similar extended crank times.

[Hib Halverson]

Originally Posted by Hog

There are GM engines which were SFI before the LT5, the 1984+ Grand Nationals with the 3.8 were all SFI engine with the wasted spark ignition system. Similar in appearance to the LT5 and Northstar ignition hardware.
The Buicks were known to have similar extended crank times.

You are right "Hog"! My statement as keyed-in is incorrect.

All the GNs had SEFI V6es. I thought I'd typed that the LT5 was GM's first SEFI V8, but I didn't.
Oops.