Hesitation in the higher RPMS

[mod_junkie]

So when I'm stomping on it going through gears my 90 325i is hesitating in the higher rpms almost like its cutting out or slipping maybe? I dont know whats causing it. Any ideas? Hoping someone can point me in the right direction thanks in advance.

[DesertBMW]

Tired valve springs floating, common for high mileage M20. Mine does it too, that's why I will get rid of the M20 soon.

[jlevie]

Tired valve springs floating, common for high mileage M20. Mine does it too, that's why I will get rid of the M20 soon.

That is not a common M20 problem, though worn valves & guides are a common problem on any high mileage engine.

More likely causes are a bad WOT switch in the TPS, aged ignition wires, distributor rotor/cap, the wrong plugs (use NGK ZGR5A), fuel supply issues (clogged filter, weak pump, bad FPR, clogged injectors), and/or a partially clogged catalytic converter.

[mod_junkie]

That is not a common M20 problem, though worn valves & guides are a common problem on any high mileage engine.

More likely causes are a bad WOT switch in the TPS, aged ignition wires, distributor rotor/cap, the wrong plugs (use NGK ZGR5A), fuel supply issues (clogged filter, weak pump, bad FPR, clogged injectors), and/or a partially clogged catalytic converter.

Thank you for the reply I guess I'll be going along that list lol

[mod_junkie]

bump

[ak-]

Had this problem on an eta.
Distributor cap contact points were a little corroded so I sanded them down a little and 80% of the hesitation went away; temporary fix.

[bddog]

My car is chipped. When I add Lucas to the fuel, it stops the hesitation. I buy it by the gallon from Amazon.

[mod_junkie]

bump

[efficient]

bad afm?

[mod_junkie]

well I was hoping someone would have maybe had this experience and could of narrowed it down to a couple different options but it looks like I will be chasing it down by replacing parts LOL

[Gregs///M]

Could be bad AFM.

[codrum]

If you haven't changed your plugs and gapped them correctly I would start there. It's quick and cheap and will rule out one of the potential issues. I had similar breakup problems in the high end (although I'm FI), gapping my plugs correctly fixed the issue.

If you can remove the chip or put a stock ECU in and see if the hesitation goes away.