Hesitation/ missing at high speed

[Jim1826]

I’m working on a 03 Z4 3.0i, back story the car sat for 11 years in a garage. I’ve been thru the entire car, new fuel pump, top pump motor, multiple wires soldered that had been chewed on by mice, multiple items repaired or replaced. Finally got the car running, everything works after figuring out how to get it out of transport mode. Took it on the freeway yesterday, when I got to 80 mph, the engine seemed to be missing and it wouldn’t accelerate any further. It didn’t throw any codes. The car has 36k and has the original fuel filter. Has anyone had a similar problem? I’ve ran 3 full tanks of gas thru the car with Techron fuel system cleaner. I hate to buy a new filter at the high cost of them if that’s not the issue. Thanks

 

[enuff_zed]

Does sound like fuel starvation but code perhaps be a coil or plug?
But I’d expect a code?

 

[Jim1826]

Thanks for replying, it has brand new plugs in it, not that I’ve never seen a new plug be bad. I’d think if it was starved for fuel due to a filter restriction then there would be enough of a pressure drop to trigger a code. I’m thinking that I’ll set my computer up and monitor as many functions as I can while driving as the next step. I’d hoped this would be a common enough issue that someone would have experienced it.

 

[Dr. Zed]

Might be a VANOS issue? Then again you'd expect a code if it was bad enough for you to notice lack of power. And for it to go at 36k would be unusual but if it's been sat then it might be the seals that are worn out.

 

[Jim1826]

Appreciate the input from all. It’s the damndest problem I’ve ever seen. I ran Techron thru two tanks of fuel and drove it like I stole it. Out on I-75 today I was running 80, mashed the throttle and jumped up to 100 quicker than I thought it should have, backed out because you never know who is watching but the problem seems to be resolved.