ive been upgrading my fuel system with a rising rate fuel pressure regulator and a walbro 321. i noticed while mapping the car (with an apex powerfc and no O2 sensor adjustment) that the fuel pressure and AFR would gradually drop as the car sat idling for 10 mins with a hot engine.
so ive spent the last few evenings looking at this. ive moved the fpr to a cooler location and insulated it, this made no difference, fuel pressure would still drop to ~0.5bar from ~2.5bar, when hot, but not too hot to touch. the fpr is being returned for assessment.
ive gone back to the stock fpr (man, that was a bitch to get back on) and a similar thing happens. let the warmup phase finish and the idle is showing 14.7:1 on the wideband. go for a hard run, to get everything hot, park up with the engine idling and AFR will start to drop. alot slower with the stock FPR but it will still gradually drop to 16:1.
is this normal?
anyone experienced something similar?
thanks in advance..
so ive spent the last few evenings looking at this. ive moved the fpr to a cooler location and insulated it, this made no difference, fuel pressure would still drop to ~0.5bar from ~2.5bar, when hot, but not too hot to touch. the fpr is being returned for assessment.
ive gone back to the stock fpr (man, that was a bitch to get back on) and a similar thing happens. let the warmup phase finish and the idle is showing 14.7:1 on the wideband. go for a hard run, to get everything hot, park up with the engine idling and AFR will start to drop. alot slower with the stock FPR but it will still gradually drop to 16:1.
is this normal?
anyone experienced something similar?
thanks in advance..