My $500 inline Fuel Filter.

[41woodie]

Many moons ago after rebuilding the SBC in my 39 Ford coupe, I found that if you wound it up pretty hard it would get to about 65-70 and just go dead as if you turned off the ignition.  Looked and looked for the problem without success.  Took it down to a shop where an OLD guy was the mechanic. (He was probably younger than I am now).  I explained the problem, he asked if we had worked on the distributor, I said "yeah we took it apart and cleaned it up"  He said " you left one of the washers off of the screws that hold the cap clamps to the body.  Went on to explain that as the plate rotated it would would then ground out on the screw that was just a bit too far in.  He was right, and he did it without opening the hood and looking at it.  He's always been my hero.

[unklian]

... I pulled the sending unit off the top of the tank and found one of those foil seals you have to peel off the top of fuel additive bottles, after you unscrew the plastic cap. I fished it out and found the perfect impression of the tanks outlet tube in the foil....

Several years ago,a big name WOO Sprint Car team had intermittent
power steering problems,for almost the whole season.

Changed all the usual expensive parts,more than once,
everything except the reservoir.

Eventually found one of the foil bottle seals in the power steering reservoir.

Expensive lesson.