Truck dying at stop lights, restarts with time

[kamps989]

Hello all,
Past few days my truck has been dying at stoplights and wont start unless I let it sit a few minutes (which is a big problem as sitting through a stop light in Minneapolis isn't thought of too fondly). This morning I was headed out and couldn't get it to restart so I pushed it home as I was only a block or so away. Got home today and sure enough it fires right up, pulled it into the garage with it IN gear and stopped it dies after a few minutes. However it seams as though if I turn the key all the way off and wait till I can here the fuel pump finish priming it will start. Once its warm it seems to run fine.

Here is where I am at -
OBDII codes for misfire on cylinder 2 and flexfuel sensor (both of which I've had for a long time)

Tested the TPS sensor

Tested the IAC sensor (read it should output 10.5v I was getting 12.5v, but it ohmed out correctly so I don't know if the variance is acceptable)

Cleaned MAF

Switched the fuel pump relay with another and no improvement.

Thanks!

 

[snake]

Odd it would do this only at a stop. You can check for a vacuum leak, that would make it have a weak unstable idle but it should throw a lean bank code. Crank angle sensor would also throw a code. It would be ideal if you had a fuel pressure gauge with you so the next time it dies you could check the pressure and be certain it is a fuel problem. If you narrow it down to a fuel problem check the fuel pressure regulator before replacing the pump...

 

[kamps989]

So I had a complete slap the forehead moment yesterday and I realized that the relay I switched was in fact not the fuel pump relay. After switching the correct one it seemed to have solved my issue, so I bought a new one and so far so good. My only thought on this is perhaps that when the engine goes down to idle the system voltage drops slightly with less RPMs and this caused the faulty relay coil to release until I completely cycled the system again and re-energized it?

At any rate the issue seems to be resolved, thanks for the help though snake!