yet another thread :/

would a bad in-tank pump cause a weak and uneven idle for 10-15 seconds after first starting? it only does this sometimes, but interestingly it got much worse (and even died after starting once yesterday) when the weather was much hotter than it has been in a while. Would ambient temperature influence a fuel supply problem? after a few seconds of anemic idle, the car runs absolutely fine, and it has no problem starting right up again after it has been running.

Yesterday, when the problem got noticeably worse, I had a full tank of gas. I haven't seen a relationship between this symptom and amount of gas in the tank.

I'm nearly certain now that the in-tank pump is dead. I've tried the listening method at the filler opening but it is difficult to tell if the pump is running because I can hear the loud main pump so clearly through the tank--and the main pump is definitely making that unhealthy sound (I went through all of this on my 940).

I put in an order for a new in-tank pump, but I'm curious to know if a malfunction there in the fuel supply chain would cause this particular symptom (and why a hot day would make it worse).