302 doesn't turn over 3500 RPMs

[cdarsey]

Greetings everyone,

I am checking to see if anyone has ran across this issue. I purchased a MK2 FFR cobra about a year ago. The issue is the car runs good until it hits 3500 RPMs and when it hit 3500 it sounds like its hitting a rev limiter. The rev limiter is set at 6700. I bought this car knowing about this issue. Since then I have changed the ignition system (plugs, wires, distributer, and MSD 6AL box). I recently installed a Jim Inglese 8 stack EFI. Now I am thinking it must be something internal. Thanks in advance for any input.

[Jeff Kleiner]

What is the fuel pressure under load when it hits 3,500. By under load I mean when driving, not free revving parked.

Jeff

[bobl]

First as Jeff said, verify the fuel pressure is to spec under load. check that the ecu and msd have clean battery and ground connections. Verify voltage from the ignition switch at the ecu and msd. Alternator not charging properly can cause those symptoms.

Now to the mechanical possibilities. It really sounds like something in the valve train. Might be a cam lobe is wiped out, misadjusted rocker arm, bent or broken push rod, broken valve spring. I just had a 1970 Boss 302 on the dyno. It would hold a load until about 3500 and then start breaking up and popping. Turns out the cam was totally wiped out.

Bob

[bobl]

Moderators...you might want to move this thread to the Roadster section. It will get a lot more traffic there.

[cdarsey]

40psi

[cdarsey]

thank you, it gives me more things to check

[cdarsey]

thanks I am still getting use to navigating this forum.

[Jeff_J.]

I see bobl has an 8 stack on his car as well - he might have a better idea on this: what does the 8 stack require for fuel pressure? Do you have an in line fuel pressure regulator as well the the gauge, is the regulator working/set properly, fuel filter in good condition? When you get to 3,500 RPM under load does the engine surge/flutter or is it a constant 3,500 without misfire.

Mechanically; a compression test might reveal valve train anomalies - valve issues might show up initially on a plug. (dry - wet - burnt)