engine questions

[ten2doyle102]

Ok, so  recently got a new vehicle with a 20,000 mile rebuild on the engine and was wondering what would cause the car to randomly "rev limit"?  Its hard to explain in words but when i have the throttle wide open it'll climb through the rpm's and then just start freaking out, almost like its bouncing off the rev limiter.  I was thinking that it would be a failing fuel pump, but my logic tells me that it would do that at the same point but maybe not.  Also the plug wires look pretty ratty.  I know that you should change them regularly. so they probably haven't been changed since the rebuild. It also has some issues with when it is at idle, it seems to hesiatate before it revs up.  That's what really made me think plug wires.  

also well i am at it...what's with the price of those thing?  where's the best place to get some new ones, and i figure, since i mine as well replace 'em, what is some good priced performance ones?  

Thanks

Matt

[e30s4evr]

My e30 M3 does that occasionally. Spraying some contact cleaner on the AFM connecter fixes it everytime.

[gearheadE30]

The AFM plugs on our cars have 2 sections. One is connected to the main harness, the other is a crossover plug that also acts as an extension. The connection between the two can leak somewhat easily. Try that.