Hesitation problem during acceleration with a 2001 1.8L Turbo Passat

My 2001 1.8L Turbo Passat (79k miles) tends to hesitate when accelerating. I’ve tried several fuel injector cleaners, new air filter,and fuel filter. Nothing showed up in a diagnostic test at the dealer. They thought there was carbon build up on the valves and tried to clean them with a solvent emission cleaner, which did not seem to help much. They also recommended running their fuel additive with the next several tanks of gas to solve the problem. Does anyone have other suggestions?

Did it hesitate ever since you got it or is this something recent?

The 1.8T engines are drive-by-wire, meaning stomping the gas won’t immediately pull a cable that works a doohicky that makes it go faster. Instead, the pedal is hooked up to a sensor that relays your stomping action to the ECU - it’s all electronic. This computer will interpret your actions and attempt to accelerate in the most efficient manner. If it always hesitated, perhaps this is the cause.

Of course, the 1.8T has a turbo lag also. If the hesitation is a new development, maybe this is a contributing reason. Perhaps with age, the turbo doesn’t spool as quickly as it once did and the lag has gotten a little longer than before?

This is a new problem. It’s intermittent. Sometimes it hesitates, sometimes it doesn’t. It’s almost like its getting no gas for a split second. It never happens at constant speeds, only when accelerating. It can happen when accelerating at any speed, 1st - 5th gear.

My 2001 Subaru Legacy has the same problem – slight to very pronounced hesitation during acceleration. Neither the Subaru mechanics nor my trusted local garage can find the problem. It is intermittent, but always occurs upon acceleration. Oddly enough, I’ve found that keeping the gas tank at LEAST half full has (mostly) prevented this from happening.

Oddly enough, I’ve found that keeping the gas tank at LEAST half full has (mostly) prevented this from happening.

In your case that points to a bad fuel pump, partly blocked fuel filter or crud in the fuel tank. All three will get worse in time.

So it’s a new problem. Hmm. If you know anyone with a vag-com or have a euro-tuner nearby, try a throttle body reset. That is a cheap possibility and may help once the ECU settles in again. If not, perhaps it is the fuel filter as suggested. The only other thing I even see that makes an attempt at addressing this is the sprint booster. I have no experience with it though and haven’t heard any testimonials.