Code 43

Alright, i got a 93 Civic Si, paid $100 for it, had to swap out heads(broke valve) and time it a dozen times, and believe its timed, or atleast on the right tooth, don't have a timing light to do the ignition timing at the dizzy. The car is a race car for the 1/2 dirt track in my back yard. Well when i first got it running, I took it out on the track and didn't have too many problems, seemed like it could go faster, but other than that, no codes or anything. Today I swapped wheels, put some 87 teg aluminum wheels on, put a makeshift intake tube and filter on(big piece of rubber tube from a ford ranger and a cone filter). Took the car out on the track and did exceptional for a couple laps, then all of a sudden around 4500 rpms it starts bouncing back and forth, like it hit a rev limit. I pulled it off to the side and checked the codes and I'm coming up with Code 43. Any suggestions? I know its a code about fuel pressure, figured I would check here and see if anyone has ran into this problem yet and what it was. Any help is greatly appreciated.

tighten gas cap and reset cel. if problem returns, get some fuel pressure readings.

Well i haven't really known a loose gas cap to cause that big of a problem, but ill check just to make sure, and I also grabbed a regulator from work, so ill replace that too and hopefully that will get it.

does ur fuel pump work?

Yea, pump works. I replaced the regulator yesterday and that seemed to do the job. Took it around the track a couple times with no problem, now just gotta fix some other odds and ends.

Shouldn't have really posted this thread, i get a little anxious sometimes, but maybe someone can use it sometime.