Weird off-idle lean issue

[nocwage]

I installed an FPR and now the fueling makes 'sense', I had 450cc dsm injectors with a walbro fuel pump but whenever I calculated the K value for my ROM I had to act like I had 520cc injectors otherwise I'd have 8:1 AFR at idle... Now that I have my SARD FPR installed I calculate the K value with 450cc injectors and the fueling is no longer way out to lunch.

However..

My idle fueling seems okay.. but if I've sat at a light for a while and then give the car a bit of gas to get going again the AFR can jump to 19:1 and it struggles to just start rolling.. once it starts rolling OR if I rev the car before going the AFR drops back to a reasonable amount and then the car runs fine again..This ONLY seems to happen when I've sat idling for a long time.

Any hints/ideas??

[nocwage]

Oh!With the engine OFF and the fuel pump relay jump'd the fuel pressure is 36psi.

[float_6969]

Try cleaning the MAFS and check out the TPS. It sounds like a tuning issue, or a sensor input issue.