Acceleration hits a wall?

[kusserwagon]

So I recently finished my m30b35 swap. Motor is from an e34 and just for informations sake I have the g260 transmission. Car runs great, idles good, temp stays down. Pretty much I'm loving every minute of driving it. Besides the fact that I still have a 4.10 differential, which means I'm at about 3,000rpm @ 75mph. But anyways, my only problem so far is that sometimes when I'm accelerating hard, usually between 4,500-6,000rpm, my car seems to hit this invisible wall and losses all power. But as soon as I let off the gas I can get right back on it and keep accelerating. This has happened a few times now. The main thing I can think of is that the clutch is maybe slipping not being able to handle the torque? The clutch is brand new bought from Turner. Any tips on what to look at would be much appreciated. Thanks everyone. By the way without this site my swap would not have gone as smoothly without all the forums from others who have done this, so thanks for that too.

[squidmaster]

Could be so many things.... AFM, TPS, injectors, TPS.

Now, when you say "hits a wall" you mean it stops accelerating all together? Or?

[EatsHondas]

Did you replace all the "tune up" related items? You can lose a lot of ignition power (ie intermittent dying under heavy load) if your coil, cap, rotor, wires, or plugs are past due.

How old is your fuel pump? Hopefully the filter is relatively fresh too!

If your fuel and spark are cutting out together, the CPS should be inspected/tested/replaced.

[kusserwagon]

Squidmaster, yes it is as if I let off the gas. But when I do actually let off the gas when it happens I can get right back on it.

Eatshondas, I didn't replace any of that stuff, but will soon. The fuel pump is older. You think it's having a hard time with the demand of the motor at WOT?

[EatsHondas]

Yes. Increased load and RPM both require stronger spark and fuel delivery. Since WOT is the most you can ask of an engine, it's a common time for problems to pop up.

[squidmaster]

Honestly it COULD be your fuel pump! There's a bunch of info on here and on the e30zone wiki about checking your current sensors. Read up on it, get a multi-meter, and track down the bad component before deluging into dozens of new parts.

http://e30zone.net/e30zonewiki/index.php/Main_Page

Check your fuel pump visually. One car I had with a similar problem actually ended up being a SPLIT IN TWO fuel pump terminal (never seen that before or since). Anyway, best to check to be safe.

Good luck and let us know what you find :)