87 5.0 maf rough idle stall

[polsport]

I just rebuilt an 87 5.0 h.o. basically stock, mild head porting,long tube headers, duals no cats. when cold stalls on idle, once it warms up it has a rough idle. sounds like a nasty cam. other than that runs great razor sharp throttle response. good power. no codes, checked all sensor voltages and baro freq. everthing seems normal. it was converted to maf. I didn't check the cam. it was in the engine when I baught it. everything else had ford markings. any ideas? Thanks hank

 

[Na5.0HO]

Not sure about the cause, but if it helps... my '88 did the same thing after my conversion and only recently stopped after I changed my valve covers. Go figure. I think it might have something to do with the computer learning to read the new engine config. Just my guess.

 

[blackstangt]

check the egr and the valve in the back left corner that controld the vac, i know if you put your finger over a working one, the car sounds like it has a cam even when stock.