2004 Passat 1.8t 4motion

[waffen6]

I’m getting random misfire at idle like one hard knock then every thing is ok. I also have no MIL light or retrievable codes. I checked for vacuum leaks don’t see any. Change out some old vacuum check valves. Replaced oil breather hose had crack. I Changed timing sensor, timing belt and fuel filter fuel pump died changed out. The old fuel filter had something rattling around in it is that normal? Also when I get gas no matter where, 91 octane only the car idle stumbles about 5 minutes after fill up then smoothes out after a mile or so. EVAP purge valve clicks some times? Haven’t check EVAP canister for saturation. Fuel regulator? ”haven’t checked fuel pressure” car was not starting after sitting for week end hard start took 3 to 4 tries then starts up ok for some reason that is not happening now?

NEW ADD 4-16-2012
found my PCV is not working will get new on from indie shop for 20 buck not bad.
hope this fixes it

[waffen6]

hooked up the new crank case pressure vent "PCV" started up ran like crapppp! restarted 2 times reset light and alls well running good so far shifting better also. My purge valve in now
clicking more? Im going to replace next. by the way the PCV i got only cost me 14 bucks.
I got it at cost cool. I guess good thing come back to people that help and care for others.
next i have to replace electronic gas door opener. this peace of crap car sucks but I have come to have a hate love relation ship since I spend more time fixing everything breaking then driving it. ha Hitlers curse lives on.

[waffen6]

purchased purge valve let see!

[waffen6]

installed purge valve runs better with less misfire. but not fixed seem to be a vacuum leak. I ran a smoke test on the vacuum system no leaks that can be seem. the only code is P0300 random misfires by the way I have not seem the MIL light since PCV was changed but still rough idle here and there. The other items that can be changed are EGR valve, O2 sensor MAF I'm not getting any error codes for the MAF or O2 sensor so I believe they are doing ok.

[waffen6]

no luck took it to a indie vw shop no luck same codes p0300 p0171. they say it may be the pcv suction pipe never know Ill try a new one shortly. I check my EGR seems ok holds vacuum found the vacuum junction under intake front one next to n112 valve was unpluged! fix that working good turns on when car is cold shut off after warmed up. engine is holding vacuum at 19.0 +- 6 in. my battery is reading 78% charged when running? seems something is straining it. im going to check the resistance on the alternator. could be not recharging battery taxing fuel pump causing lower fuel then needed?

[waffen6]

car running battery reads 14.1 with lights on. 12.1 with car off little low. sprayed all vacuum lines with choke cleaner no change in idle. order PCV suction valve. find a MAF while driving Maf reading was 46in 38in

[waffen6]

OK,
removed cleaned crankshaft sensor and check ohm. Everything seem good. I hoped that it was throwing the timing out no luck. car still sucks ass. Then I was just staring at the car while it ran like I have done every day since it took a crap. I dont know why but I poked at the 3 way rubber breather hose that goes to the PCV suction valve WOW. I heard a hiss every time I poked it. I remove it from the car and what i saw was, horizonaly inline under hose clamp a slite under and out of sight. I cut the hose and repaired it with a small pipe and new hose. I have a new 3 way breather hose on it way. 15.00$ bucks

FIXED FIXED FIXED
Codes where P0300 P0171 also small leak detected in evap system

So when every one in this forum says to check for vacuum leaks check once check twice check three times do it again and again and then do it all over again
on a good point most of my emissions system is new. The car will give me another 70k i hope.