Just throwing out there, I've currently got an issue on mine where it keeps running after key off when the AC blower is on (somehow backfeeding voltage I'm sure, just haven't dug in). It isn't really dieseling, but it is definitely running weaker and I could imagine the extra load of the PS pump could stall it out. If I leave it alone with blower on high, it will continue running for 5-10 seconds, shorter when the blower is on low I think. It's also TBI, not sure how hacked up yet since I plan on pulling it all later, but it is at least mostly stock. I had a similar issue on another where an electric fan relay was powering up the ignition circuit when the fan was on high (long story, not a stock setup by far), and anything keeping the computer on can keep the engine running to some degree.