Hi all,

My 98 2.8 30v is starting rough after sitting overnight. The motor sputters for 5-10 seconds initially like it's not getting fuel pressure and then it starts.

I'm thinking either fuel pump or Fuel Pressure Regulator. Is there an easy way to isolate the problem? I'm going to check the FPR vacuum line for gas and also pinch the FPR vacuum line when starting to see what happens.

Thanks

 

just a random thought...when did u change ur spark plugs last... since im running colder plugs my car will stutter before calming itself down after sitting for a night just a thought

 

I changed the plugs six months ago with Bosch OEM and the car was running great until last week.

 

it might be the evap purge valve. mine used to do that when id pump gas

 

Prime the pump when you start it - turn the key on and leave it 2-3 seconds before cranking to build fuel pressure. That may help.

 

Or you may have a coolant temp sensor beginning to fail. They're notorious and can create all sorts of issues.

 

I replaced the coolant temp sensor six months ago, so it should be okay. Priming seems to help. Ordering a new FPR today.

 

I was able to pull a p0411 "intermittant" code using VCDS lite. Looks like a secondary air pump issue, either the pump, vacuum lines or combi-valve(s). This makes sense because the car has been starting fine in the recently warmer Boston weather. I cleared the code and will see if it shows up again.

Once during hard starting, it smelled like the motor sucked in a bunch of carbon. Motor has also been running fine since then.

Does anyone have an idea as to what coolant or ambient temperature triggers the secondary air pump, to assist with cold starting?

 

If you haven't replaced the small vacuum lines on top near the back of the engine, that's probably the first thing to do as it's cheap and fairly easy to do. I had the same code on the same car recently and that seemed to fix things - at least no codes pending or otherwise after considerable driving. Trying to pick which hoses are bad is not worth the effort just replace them all. Don't miss the one that's teed underneath the plate to which the various valves are attached.

I got the replacement cloth braided line at BAP - they sold it by the foot. Six feet or so should do, i had extra after buying 8 ft.

 

Thanks -- I replaced a bunch of vacuum tubing six months ago, but not the lines going to the combi-valves. Looks like a pain to get at, but maybe next weekend I'll get in there. Car starting 100% perfect now.