So, I've got a near mint (lol) 1990 245 DL M47.. The engine bay is very clean and has a K&N filter, new fuel pressure regulator and is the Florida model (no rust) with the EGR valve. Also just replaced the fuel filter. No leaks, starts strong, OEM everything. No strange aftermarket parts where they shouldn't be.. Lucky me, right? Anyways, everything is fine. Starts clean and strong, and runs perfect. All except when you're in the highest gear, it lags.

Imagine you're about to go up a hill and you shift to 5th a little early. That's when the lag shows itself. If you can imagine about halfway up, you'll probably need to go down to 4th. Now with an empty trunk, this isn't too much of a problem. But I know in the near future I'm going to be loading it down, and I know I'll need all the extra bhp I can get. So my question is, Where do I start? I thought the fuel filter would fix that, but no...

Should I look at the injectors? Maybe check the voltage going to them, or send them off to be cleaned? I know the plugs, wires, cap and rotor are new.. Where else could I look? I guess I'm wondering if anyone has any suggestions before I start monkey-ing with the injectors. Sending them off to be cleaned when they're probably fine, and finding out it didn't fix the problem, is not what I want to do. 80-100 bucks is still 80 to 100 bucks..

I guess I haven't cleaned the throttle body in a while. Suppose it could be that. Where would anyone else start?...