My new-to-me S60 T5 has a hesitation or surging under light throttle acceleration. If it were carburetted, I'd say it is jetted too lean.

Under moderate of heavy acceleration, the car performs perfectly.

There are no MIL Codes in combination with this problem.

Anyone have suggestions?

Bob

 

try putting a bottle of fuel injector cleaner in the gas tank....also check your spark plugs....if your plugs have not been changed they could be do and this could effect your cars performance..also the injector cleaner will help should the injectors be clogged! please post your findings/results.

 

I've run two tanks with Amsoil fuel system (and valve deposit) cleaner in the fuel. This is the now discontinued stuff that I've been told is extremely effective (but which was rather expensive).

I have always liked Techron (the concentrated stuff, not the 10% Techron injector cleaner), and will try that next.

I've heard sucking a can of Sea Foam into the engine through the vacuum brake booster hose, allowing the engine to stall, and sit overnight to soften deposits, is helpful in some cases.

I have a workshop manual, but it doesn't address removal and cleaning of the mass airflow sensor and throttle body (which is completely concealed below the intake manifold in the 2.3l T5 engine).

Anyone have a good photo of how to remove the throttle body on a T5? I am sure it could use a good cleaning. It made a big difference with my Volvo 965 a few years back.

BTW, the engine idles perfectly smoothly, not as one would expect if the injectors were slightly clogged, but that may not mean anything.