Sounds like a therapy question,no co confidence in husband ,sorry can't help with that
SOURCE: 02 Santa Fe
The mechanic is stumped, he has no clue what the problem is. but i have figured out it is not only when i gas up. i removed the gas cap with the car running and the car started shaking and running crappy, i also heard the gas bubbling inside the gas tank. i will call the mechanic with th new findings. will post when we can figure out what the problem is.
SOURCE: cannot read codes
Try disconnecting the battery again then hook it back up and see if it resets. We will go from there.
SOURCE: mass air flow sensor replacement (variable valve timing)
The MAF is on the Air Intake above the air filter box and screwed into the plastic tube heading toward the throttle body. It is the 2" by 2" plastic protrution from the air intake tube. There should be two philips screws holding this in. Remove the two screws and back the entire MAF out. There is a wire harness connected, unclip this to remove completely.
If you have money burning a hole in your pocket, go ahead and purchase another MAF for a few hundred clams, or you can spend about $10 and clean it. It's made out of titanium and I doubt it will fail in 10 years. But sometime it does happen.
Go to Lowes, or Home Depot and buy Electronic Cleaner in a spray can. If you look inside the sensor, there is a heated wire, and behind that is another wire which picks up the oxidized air.
Stick the tube which is attached to the electronics cleaner spray can into the cavity where these wires are seen. Continue to spray most of the can onto these wires to remove oxidation build up from the wires. Let it evaporate for a few minutes then hit it again.
Allow the assembly to evaporate complete for about an hour.
In the mean time, take some throttle body cleaner and spray out the throttle body with the valve open. Keep open to let it dry out quicker and clean up the black crud that come out.
Keep you air filter replaced.
Put everything back together and you should be good to go.
DIYr-X
SOURCE: Which mass air flow sensor fit ?
Why are you changing around on part no.s They are all calibrated to a specific application. Get the same part no. as what was removed.
SOURCE: turbo problem...dealer replaced valve...still
If you have a problem that isn't caused by something obvious, you need a Ross tech VCDS cable. This is a laptop computer diagnostic cable to talk to the car's computer. Without it you cannot do the more advanced tests.
Note about generations - some generations have similar engines:
Mk3= 1996-1997 3rd generation Passat TDI or 1996-1999 3rd gen Jetta TDI
Mk4= 1998-2006 New Beetle, 1999-2005 Jetta, 1999-2006 Golf, 2004-2005 Passat TDI
Mk5= 2005.5-2010 Jetta TDI
Mk6= 2010+ Golf TDI
Remember, an engine needs fuel, air, and compression to run. Low power is related to a lack of one of these or a sensor problem making the computer thinking there's a lack of these. Any sensor problem could also be caused by a bad ground or broken/chaffed wire so also check every section of the wiring of the suspect sensor for breaks.
Bad MAF sensor - very likely cause on the mk4 TDI. Not common on the mk3 TDI (1996-1999 Jetta/Passat). Early mk4 MAFs failed often.Error codes normally do not show up with a faulty MAF since the signal degrades instead of going out completely. Through VCDS, checking MAF actual vs. specified at idle, high rpm, and high load will quickly show a bad MAF or other problem causing a low MAF reading.
Clogged intake manifold - carbon buildup chokes the intake manifold, starving the engine of air. Only ultra low sulfur diesel is sold in North America now so there should be much less buildup in the future. Always use good quality synthetic engine oil on your TDI..
Anti shudder valve shut or almost shut (does not apply to mk3 TDI, more for mk4 TDI) - there is a spring loaded valve right before the intake manifold. Newer TDI use an electronic valve and are not as susceptible to sticking. If there is excess carbon buildup, it could shut in a partially closed position.
Clogged snowscreen/air filter - a clogged air filter will starve the engine of air. A clogged snowscreen (large debris air pre-filter) shouldn't block off all air unless the aux-intake flap is also clogged.
Clogged fuel filter - change interval is 20,000 miles but biodiesel use (cleans out old buildup) or bad fuel could clog it early, resulting in fuel starvation. Algae or bacterial growth in the fuel tank could also clog the lines.
Boost leak - a cracked hose or loose connector lets measured air out. No air or major leaks = poor engine running or stuttering. A visual inspection may not reveal all the possible or hard to see spots where leaks can form.
Hose inside ECU (mk3 TDI only, does not apply to mk4 or newer TDI) - this hose leaks and normally sets a check engine light,
Vacuum lines to/from turbo and n75 solenoid - these dry out over time and crack or can rub through. It's possible they are clogged. The n75 solenoid controls the turbo wastegate or VNT vanes with either vacuum or pressure. b4 Passat - on firewall above coolant reservoir, a3 Jetta - on pass side near air box, a4 Jetta/Golf - on firewall above brake fluid reservoir.
Problem with the n75 solenoid, VNT actuator, VNT vanes, or vacuum lines. You should have already checked the vacuum lines, the below test will inspect the entire system. Start the engine and through VCDS, click on "engine"-->"measuring blocks"-->hit "up" until you reach "group 11". Compare Specified vs. Actual MAP. This compares what's actually happening and being observed from the boost sensor (barring a faulty sensor/plug/wire) to boost the computer is requesting (what should be happening). They should be relatively close. If they are far off this normally results in limp mode but it could also be contributing to the problem. If you have a mk3 you have a conventional turbo but you can still use this test to check the n75 solenoid, the wastegate, and vac lines. However, wastegates are much less susceptible to sticking vs. VNT vanes. The videos below show how it works. The lever on the outside is welded to a lever inside the turbo housing. This is how it moves the VNT vanes. See the below videos to see how smoothly and free the lever should move. It should not stick or bind at all. Vacuum is being applied to the can, not pressure.
If the test shows poor response or no response at all, it could be sticky VNT vanes/actuator (mk4 and newer TDI only), The vanes or actuator can stick or fail to function, the lever should move freely.
If the actuator is fine, also check the n75 solenoid and vac lines. The n75 solenoid controls vacuum or boost to the vacuum line going to the turbo wastegate/VNT actuator. To test, apply voltage to the solenoid or swap with a known good unit. If you have a mk4 TDI, you can swap it with the EGR solenoid to test. Also check the plug for corrosion and the wiring harness for chaffing. If those are good, disconnect the VNT actuator rod and move the vanes by hand. If the vanes are stuck then remove the turbo and clean the inside of the exhaust housing to free the stuck vanes.
Faulty injection pump's fuel injection quantity adjuster - these are occasionally set wrong from the factory or after seal replacement. It's also possible the fuel pump's internal quantity adjuster is faulty. Applies to 1996-2003 TDI only or TDI that use a Bosch VE injection pump (not pumpe duse or common rail). Injection quantity should be 3-5 at idle and up to 36-38 at full throttle.
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