I haves 98.5 a4 1.8TQ and I think it needs a new fuel pump check valve, i went on ecs and they have like 5 different ones and I have no idea which one I need here's the link: Home Page > Search > Fuel Check Valve - ECS Tuning Inc though it may not come up for you. None of them tell which models they fit and that's after me putting my car in. Anybody?

 

May I ask why you think this is an issue? Pretty sure your car doesn't have a separate check valve unless you're running an aftermarket fuel pump like the Bosch 044.

 

Very long start times, hesitation when pressing has when cold, low fuel pressure. Replace coolant temp sensor and fuel filter.

 

Get an inline fuel pressure gauge. They're $20-ish. This will tell you whether or not it's a fuel pressure problem.

 

If it does have a check valve its not available separately according to our sources.

Could be the fuel pump is dying. Couple other factors lead to long starts like the crank position sensor.

Jason

 

I'm going to clean the fuel injectors and test the pressure and post back here, thanks for your help!