LuTTs

My 2001 TT 225 has been difficult to start after sitting for a few hours. It cranks fine, just doesn't want to fire. Once it is started, it runs fine with a rough idle. I assumed this was from the rail losing pressure while sitting. If i start it, let it idle for a minute, then shut it off. It will fire again right away. I suspected a leaking injector, so i sent them off to be cleaned and tested. They are fine, if anything, problem may be a tad worse after injectors went back in, but not sure. I haven't yet been able to get my hands on a fuel pressure tester to see how long the rail will hold pressure after it is shut off. No obvious leaks under the car or in the engine bay. I tried to do some research on whether or not there is a check valve at the fuel pump or what else is there to fail and cause this. I'm really struggling to find any decent info on the car overall. Any suggestions and info is definitely appreciated. Thanks guys.

P.S. bought the car with the rough idle and starting issue, no guarantee at all they are related, just thought id throw that out there.

J. Patterson

I suspect your fuel pump is failing. The pump runs as soon as the key is turned to on. If you pause a second before starting it SHOULD help.
Does it display any fault codes when scanned?

LuTTs

No codes when scanned. I don't believe the pump primes when the key is turned. I've always read it's not supposed to do anything until the engine is turned over on the TT, unlike most cars. today I was able to do some testing with a fuel pressure guage. I went out and hooked it all up. Then started the car, fired almost right away (been sitting for a week) odd. Pressure is 40-42 psi. Pulled the vacuum from the regulator, shot to 50+ psi. Partially placed hose back on. Went to 45 psi. Then back to normal when fully back on. Shut the car off, immediately falls to 35 as expected Let the car sit for a while. About an hour and a half. Had leaked down to 20 psi. Started the car again, was slow to start as usual. Ran fine. Then shut it off again, let it sit for 20 min. Fell to 30 psi. Started pretty quick that time, but still stumbled as soon as it fired. I'm not sure these pressure numbers are enough to cause any of this. But I can't find any sort of spec outside of the general consensus that any vehicle will leak down after about 30 min. Starting to wonder if my problem is fuel related at all.

Walpole5

I know that when I have problems with these cars, I just put new plugs and coils on it. It may help with your rough idle and possibly starting. You should get a code for misfire with bad coils, though.

LuTTs

UPDATE: I was driving the car this past weekend. Same issues as always. Until mid day on Saturday, car started slow, then about 5 min into the drive, I was leaving a stop light in first gear and the car just stalled. Then it would not restart. I scanned it and saw and P0322 code. This seemed to make sense, crank position sensor could cause all this. So I had the car towed and changed the sensor the next day. Car started again and but is still showing the same symptoms. Has not stalled again yet, however i don't believe changing the sensor did anything. If anything, i would guess it started again because it sat for a day. I checked the resistance on the old sensor and it checked fine. Haven't had a chance the mess with it since then, not sure if this points to any possibilities.