Mechanics

I HAVE A 5 SPEED WOLFSBURG EDITION AND IT HAS BEEN STALLING, AND MOST OF THE TIME IT DOES IT WHEN I COME TO A COMPLETE STOP.

1999 Volkswagen Jetta • 14,400 miles

The car stalls hard to start and does not over heat and the check engine light comes on
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Mesanto
November 23, 2011.



The first thing to do is have the trouble codes pulled and see what comes up. Advance Auto and Auto Zone do this for free.
You should also check the fuel pressure. Test gauges are available at the aforementioned auto parts stores on a loaner basis. The test port is on the fuel rail and the test kit will come with adapters.
The fuel pressure at idle should be 36 PSI. To check the fuel pressure regulator, disonnect the vacuum line runnning from it to the intake manifold and the fuel pressure should rise to 44PSI.

Ok sounds great does that mean the fuel pump may be going bad?

Tiny
Mesanto
Nov 23, 2011.
Not necasarilly. One thing I thought of is to check the Idle Air Contorl Valve. It is located omn the intake manifold near the throttle body. It will have an electrical connector or a large vacuum line going to it and may have coolant lines going in and out of it. They change the A/F ratio by changing a port that by passes the butterfly and comes out in front of it in the throttle body entrance. To test a vacuum signalled IAC, remove the IAC and run the motor. Reomve the vacuum and see if the plunger or diaprhagm moves freely. In an electrically signalled IAC, test it by removing it and while running removing the connector and seeing if it moves. Sometimes the port or the pluger gets carbon deposits that require it to be cleaned. Always clean out ports psraying from the outside in towards the intake so you don't puch deposits furhter into ports. Don't use carb cleaner on rubber parts, use brake cleaner.

Checking the fuel pressure will tell you 2 things. If the pressure with the vacuum line on is at spec, the fuel pump is okay. If the pressure does not raise to spec when the vacuum is removed, the fuel pressure regulator may be bad and need replacement.

Ok I have the codes that I have from autozone and they are as follows P0102-MASS VOLUME AIR FLOW SENSOR. P1127LONG TERM FUEL TRIM TO RICH P1582 IDLE ADAPTION AT LIMIT
any help on what to do next is greatly appreciated when I took the clamp that holds the sensor to the air filter area it had some oil is that an issue I need to look at as well?
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Tiny
Mesanto
Dec 6, 2011.
So there is oil in the MAF? That might prove to be too much for it and it may need replacement. The other long term rich code refers to the Idle Air Control valve that keeps the mixture and idle steady. They work together. You can try MAF cleaner, but noticible oil ion it may be too much as the sensor wires are the diameter of a human hair. As to how the oil got there, there may be an issue with the valve stem seals. Keep an eye on smoke coming from the exhaust. If you see a blue-grey somke, the valvestem seals may be leaking and need replacement. This may be how the oil got into the air filter area unless you use a K&N type oiled filter. Then you probably just over did the oil.


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