Odd Vibration / Power Loss

[Black91SHO]

I've got a '91 SHO Plus with 88K on it. Hasn't been driven hard it's entire life. I get my hands on it and it's got a very odd vibration and at least 30 horsepower loss. The motor mounts are SOLID as well as the subframe bushings. The throttle body is fine...everything looks find externally. The only problem is that I feel a weird vibration coming from the pedal and major power loss. Oh, and the clutch is very strong. Any ideas on what could cause this??

Ford Dealer said it was an "air intake valve", but I think the mechanic just didn't want to sound stupid, because he couldn't figure out the problem. We have 12 air intake valves and I doubt one is faulty all of the suddent.

The only thing I can think of is a clogged cat, but if someone babies the car from 0 miles...do you really think they'd **** a cat?? I plan on having the cats replaced as soon as I can to see if that does it, but any ideas or input on this would be great. Thanks in advance.

Jason

 

[sdpatt]

Jason, there are several very SHO-knowledgeable individuals in the DFW area that can help you find the cause of the problem. Try the Topica Lone Star SHO Club (LSSHOC) list to post this condition. There are several in the midcities area. I live in Richardson just north of LBJ freeway and east of Central Expressway. If you would like me to look at your car, give me a call at 972-238-9574. It could be a misfiring cylinder, but without first hand evidence, it would be very difficult to diagnose.

 

[AutoSHO]

If you want the problem diagnosed correctly, the first time, go see Scott. My guess would be Oil in the plug wells causing a misfire.

Just out of curiousity, has the car ever had a 60K Maintnence done? This would include Plugs, Wires, Valve Lash Adjustment, Timing Belt, and some miscellaneous other parts that can be replaced.