Messed up rev-limiter

[silvercv2002]

Running an '80 Capri with a 306, C-4 trans. 4.10 gears. Car is set to rev at 7000 rpm but is stopping at 5500 like it is set there. Any ideas? We got a 7000 chip in it. It's an MSD 6 AL box. Car runs to 7000 in the burnout box, then shifts at 5500 down the track. Any ideas?

[Sparky]

I ran across this a day or so ago. Maybe this could help shed some light on your problem.

http://forums.godragracing.com/viewtopic.php?t=26123

Have you tried a different 6AL Box or Coil? Is the car set up to shift @ 7000 rpm via electronic shift box, or shift solenoid? Will the engine just not pull past 5500RPM going down track?

Let me know what type of set-up you have and what you have tried to elminate the problem.

[Jim Monson]

Is it a MSD Digital 6?

[Monty Mikho]

Is it a MSD Digital 6?

Jim it says its a digital 6 in his post :D

[silvercv2002]

Thanks guys, will get back to you....

[silvercv2002]

Unplugging the tach and using a different 6-AL box didn't work. Going to try a new coil tomorrow and see......

[Jim Monson]

Is it a MSD Digital 6?

Jim it says its a digital 6 in his post :D

I can't read. Public school. I heard that the little dials on the digital 6 boxes stick. MSD told a friend of mine to turn the dials back and forth a couple of times and they would un-stick. He just turned the dials back and forth a couple times and the rev limiter worked. Stupid huh?

[silvercv2002]

Hey, we are willing to try anything!!

[katman]

I don't have my brake in yet, but I switched from the blaster 2 to one of those big honkin heavy blue HVC II coils and the Adapt-A-Cap and gained .15!!! I love the Digital 6! I can't believe people won't up the $60 over the 6AL. Digital 6 is SO MUCH BETTER!!! Now I want to move the Digital 6 to the wife's car and get a Programmable Digital 7 for my car!

[silvercv2002]

I'll run that by the finance dept.!

[silvercv2002]

Well, after changing the coil, MSD box, disconnecting the tach, it looks like we may have a fuel problem. Was actually brought to our attention from none other than Don Masta! Will keep you updated!!!

[Sparky]

Thanks for the update and keep us posted

[silvercv2002]

Well, I think I've got it!! We changed the coil, tach, tried 3 different MSD boxes, checked fuel pressure. We ran the 306 on Sunday and it would only rev to 5,200 rpm. After 4 runs it started making valvetrain noise, nothing serious, but still noise. Anyway we thought it might be the valvetrain floating so we pulled the heads tonight and everything looks a-ok. Then I learned that the cam was a hydraulic piece and the rest of the valvetrain is roller. The motor has been assembled for 3,000 miles (we did not build it), and the cam looks pretty worn. I think that after we put a roller cam in it, we should be good. If not, we may be losing fuel pressure at the high rpm's. We are going to hook a guage up and see. Will let you guys know.......

[silvercv2002]

Well it was the cylinder heads. We could push a couple of the springs down with our hands. :shock: Changed over to some Edelbrock's and all is well. Ran a best of 11.97 today with a LOT of wheelspin. Revs right up to 6,500 now. Thanks for the help guys! We will see you out there next year........