I have a '94 FD which has a problem I haven't been able to diagnose.

On a long 2nd or 3rd gear pull (from say 3,000), I gain power until about 6,000, where the power seems to be flat and the engine seems to vibrate a little. If I start accelerating at around 5-6,000 RPM I get "more power" (how much is hard to tell) and much less vibration (a seemingly normal amount). The boost pattern 10-7-10 for the low RPM and builds quickly to 10psi when starting at high RPM.

Any ideas?

 

What's your engine vacuum or compression? Both of my old engines would make the right boost pattern. But they were simply worn out. Therefore, acceleration was flat.

 

Vacuum is anywhere from 15-20 mmHg at idle. On deceleration I can easily see 25-27 mmHg.

I saw even compression on both rotors when I tested it with my standard compression tester that had the valve removed. The engine was a little cold, and I think I remember the compression being around 80-85. I should check compression warm and also with the valve in to get peak compression. I won't have time to do this until this weekend.

The power seems very good up until the point where it seems to fall off. My blitz SBC color meter thingy tells me I make around 180 HP at 5,000, and when I wait to floor it, I think I have hit around 205 at 6.5k RPM. This calculates your HP by using wheel speed and vehicle weight, so there is going to be some significant error, but it should be in the ballpark.

Hopefully this helps.