Hello all. My car has been weird since I got it in a sense that once I hit 6k rpm to 65k rpm it feels like it hits a brick wall and almost sounds like a rev limiter. The odd part is it doesnt always do this.Its in every gear and it seems if I bring the rpms up slowly it will usually go to 7k no problem but not always and some times during spirited driving it does fine and other times not. Im new to these cars and really having a carb'd car in general. At first I thought it was me getting used to mechanical secondaries but now not so much. Its hard to tell but it really feels like it just leans out to much. I wanted to get opinions before I started spending money I dont need to spend.

The car has a sterling nikki carb, holley red pump, holley fpr(not positive what its set to,Cant find a small enough gauge), stock ignition, and a full RB sp exhaust. Also there is no more rats nest. I had one person that rode in it say it felt more like a small vacuum leak that was more pronounced at higher rpms but to me it just feels like its fuel related. Any opinions or advice is much appreciated!

 

Sounds to me like it's not getting enough fuel once you hit the high RPM's. Sorry, I'm not much of a fuel system expert so I can't say where to start, but it definitely does sound like a fuel system issue.

 

Definitely sounds like fuel starvation in the upper RPMs. With the pump and the
regulator your using you should be fine. It could be some these issues:

1. Tank is not breathing well and develops a vacuum. Make sure the vent line is
unclogged and freely breathes.

2. Filter is clogged or old. Change it. Get a see through one so you can tell next
time if its dirty.

3. Pump is weak or old. Do a flow and pressure test to see how it does. Should
pump a half gallon of fuel at the carb if flowing well. Make sure the pressure is
holding steady at high RPMs. Take a guage and tape it to the windshield and
drive around and see how it does.

4. Tank is full of crud and will clog new filter soon enough if thats the case. Drop
it and clean, its the only way sure way to fix it.

5. Check the float levels and make sure they are getting filled up to the line in
both windows. If not then theres a carb issue to deal with.

Out of ideas at this point.

 

^What Tim said. I'd change the fuel filter first. Cheap and fairly easy.

 

Filter. Always the filter....

 

^ Agreed, two years of driving and went through 2 fuel starvation issues due to the fuel filter

 

I had almost the same issue, engine would just stop accelerating once I got near 6K RPM. Only happened to me in 2nd and 3rd gear though... was fine in 1st. I replaced the fuel filter (which was nasty inside) and the problem is now gone. So I would try the filter first... only takes a few minutes to swap it out with a new one.