Stalling while driving

BABEMATA

MEMBER
2004 FORD EXPEDITION
V8
4WD
AUTOMATIC
162,000 MILES

My SUV Eddie Bauer Edition will stall at anytime fast or slow. The only code that it shows is "too lean bank 1". It has been to several mechanics with several diagnostics done and no solutions. We cleaned the MAF sensor, seemed to fix the problem for about three months then started stalling again. The engine just shuts off and will restart almost immediately. Longest it took was about a minute to restart. Replaced the MAF sensor worked for another three months and just started stalling again. The only other symptom is a slightly rough idle when just under 1,000 rpm and then corrects itself. It also just started making a humming/whining noise when on and gets worse with acceleration or deceleration. Could be unrelated not sure. Any ideas would be appreciated. We are stumped!

3 Replies

BMDOUBLE

MECHANIC
1,139 POSTS

Inspect the intake for vacuum leaks. The PCV system is also problematic on the 5.4 3v engine if that’s what you have. Pinch off the line on the driver side and see if the idle improves. The valve is actually mounted inside of the valve cover. Also inspect the brake booster vacuum elbow on the rear of the intake manifold for leaks.

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Wednesday, May 1st, 2019 AT 5:00 PM

BABEMATA

MEMBER
2 POSTS

It has been inspected for vacuum leaks. A minor leak was found and I was assured it was not big enough to cause any problems. Is the PCV system where the crank shaft angle sensor is? That is one of the things that is getting checked on thanks to another post I saw here.

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Thursday, May 2nd, 2019 AT 7:27 AM

KEN L

MASTER CERTIFIED MECHANIC
43,351 POSTS

Yep, the crankshaft sensor is what I would replace, it gives you a clue at slow speeds partial failing and then catching itself. Here is a guide that will walk you through the repairs and diagrams below to show you how on your car.

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

Check out the diagrams (Below). Please let us know what happens.

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