Missing at High RPMs

I was reading a tech post on Austin Area Stangs where a guy had just installed a 6psi blower kit on 95 Mustang GT, and it was pulling hard until 5000 rpms, but then it fell on its face and acted like it was missing. I had a very similar issue on the 1990 Eagle Talon Tsi AWD I had back in the day. If I would run around at the stock 8psi of boost, it ran great, but if I would turn it up even a pound or two, it would fall on its face around 4500rpms.

I nearly pulled my hair out over that one! I was checking sensor voltages, looking for codes, checking boost and fuel pressures, reading plugs etc. and everything I checked was coming up fine. I spent hours scouring the web and reading through the archives of the old Talon Digest mailing list. (an incredibly invaluable resource for DSM owners that went the way of the dinosaur about six or seven years ago.) I was looking into high-dollar boost controllers and fuel-cut defencers, etc. I had just about exhausted every high-tech diagnostic trick I could think of, and then I remembered a piece of advice my friend/automotive mentor Dan Finn gave me when I was 17 or so. He said, "Scotty, it's gotta have air, fuel and spark. It's as simple as that." Now I know that sounds basic and obvious, but breaking it down to those basics made the reason for my elusive miss become suddenly apparent. I had air, I had fuel, must be spark... A $60 set of Magnacore wires and some NGK plugs, and I was pulling 14psi all day long! I spent DAYS hunting that down and it just needed a tune up!

I guess where I'm going with this is before you mod any vehicle, take care of the basics first. Give it a good complete tune up, brake job, check your tires, change your fluids, etc. before you go adding a bunch of speed parts (especially nitrous or boost!) Also, when you get stumped trying to track down a problem, go back to the basics... Does it have fuel? Does it have air? Does it have spark? Answer those basic questions first before you start tearing it apart!