bl85c

iTrader: (2)

I've noticed a stalling problem on initial cold starts. It starts, idles down stalls and dies. Only happens after it's been sitting longer than 5 hours.

1986iroc350

iTrader: (1)

for what type of engine?? mine does that as well on my 86 iroc TPI

bl85c

iTrader: (2)

2.8 v6 w/ '165 ecm.

RednGold86Z

iTrader: (1)

90% of the time, too lean (unless it's rediculously rich, or IAC steps way to low). Afterstart enrichment (and the decay factor) is the first place to look. Open loop afr enrichment vs coolant temp might need a few % too, but typically if it's so close to the starting, the afterstart is the usual weakspot. Spark advance can help a leaner startup run, but typically won't be the actual cause of the stall.

bl85c

iTrader: (2)

I had startup enrichment set at about 13:1 across the board, guess that wasn't enough. Reprogrammed it to about 12.5:1 and didn't die, but bogs occasionally. 12:1 should fix it. Thanks again RednGold86Z.

RednGold86Z

iTrader: (1)

Always welcome!
As a reference point, on a small 4 cylinder, the peak afterstart fuel enrichment in the 50 degree F range is nearly 8.7:1 commanded AFR (not counting enrichments for warmup and speed density). The resulting burning AFR is about 13.5-14.5:1. This is with speed density. Your engine will respond differently, though. A lot of the afterstart fuel is wasted, and the wasted amount depends on the hardware and engine size. The fuel wasted is not directly associated in a % basis, because the fuel goes through as unburned mass. The amount of fuel that vaporizes and burns is what counts. From what I've seen, different size engines with the same injectors may need larger enrichments for smaller displacements (similar fuel wasted, but less air injested = more % enrichment relatively).

06andersen

i gues i dont understand what that is??