Checking my car, all the plugs are fine, wires fine, rotors and dist caps brand new. The car idles fine in park, as soon as you put the car in reverse or drive the car begins to periodically have a miss. Driving the car it stumbles at red lights and bogs down when your in the gas. I found one broken vac line that goes to the modulator valve, that didn't help the issue. In diagnoising I removed the electrical connector off the MAF and it had not affect on the idle issue. It didn't make it idle any worse, I got my test light and none of the pins had fire on them coming from the plug. This is my issue I am sure my car is running without the MAF metering the air/fuel ratio. Where does the MAF get its power from, the wires that go to it look to end in the computer box possibly ? Any help is appreciated.

If it is the MAF you should get a code. Have you scan the computers to pull the codes. Is your MIL/CEL on?

If you disconnect the MAF while running the computer uses the last known GOOD input.

Try starting with it disconnected & see what happens.

Fuel pressure, timing, & air mass all are involved in the engines ability to accelerate.

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MERCEDES Benz Master Guild Technician (6 TIMES)
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Should the plug that connects to the MAF not have juice on any of the wires inside the connector? Doesn't that look like that is my issue seeing how the connector doesn't have any power on it to operate the MAF?

I tried starting it with the MAF already disconnected before start and it made no difference, the idle is the same as always, an occasional slight miss. I then plugged it back up while the car was running and it didn't change a thing. What controls the MAF? does the ECU power it?

do a search, I had the same problem. It turned out to be the fuel pressure regulator.

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2010 ML350 Bluetec
2012 Mustang Convertible

Have you tried replacing the Delco-type fuses on the top of the base module? It may be a cheap fix. The fuses are located on top of the N16/1 in the picture here. http://www.k6jrf.com/MB_X11.html

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1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles

I checked all the fuses in the base module....they all tested fine........

Is the base module what sends power to the MAF harness plug?

You really need to scan for codes. At this point you are shooting at the air. Atleast if you have a code you would get a better idea of what's going on. For what your saying the MAF may not be the issuse. Is the hot wire in the MAF broken? If not then you need to scan the codes to see what else could be causing your problem.