My blazer will idle high at startup and if I dont let it warm up it will bog down at lights. If its warm it will run with little hesitation but will idle up when stopping. Neither way is consistant. I have replaced the fuel pump(bosch)fuel pressure regulator, egr valve, fuel filter, IAC, and done electrical checks on all the fuel related sensors to include the TPS. It does fail a fuel pressure test. It will go to 60 psi while the pumpis running, but it will immediately begin to lose pressure when it stops. The plugs are all tan colored.I have a CSEMFI(spider leg). Could this be my problem?The poppet lines seemed hard and fragile.