2004 Expedition Nightmare Won't Start Unless Jumped Off

[MrGoodwrench]

I’m a former GM Tech, and I need help! My wife has a 2004 Eddie Bauer Expedition with the 5.4L, 4x4, every option, 140,000 miles. We’ve had the car for about 2 years. Everything was fine until one day, it developed a dead miss. I pulled the codes and had a Cylinder 5 misfire. Replaced the coil, no change. Replaced the injector, then it would crank, but wouldn’t start! So I put the old coil and injector back in #5, and it still won’t start! Tried until the battery started to sound weak, with no luck. So I put a battery charger on it, and it fired right up! Drove it down the road and it drove fine all the way to town and running errands (I left it running when I went into the store). Drove for about 30 mins with no problem. On my way home, I was driving down the road and the security light on the dash started flashing and the engine lost power and started misfiring like crazy. Pulled to the side of the road and the engine honestly sounded like a diesel, as the security light on the dash kept coming on and going off in no particular pattern. Then, all of a sudden, the security light goes off and the engine returned to a normal idle. Got back to the shop and shut the car off. Now, it will turn over, but won’t start, and as it’s turning over, the starter relay in the passenger floorboard fuse box clicks on and off rapidly the entire time the engine is turning over. When you’re under the hood as somebody tries to crank it, there almost sounds like there is a rotational “click”, like something is shorting in the alternator every time it passes a certain point in its rotation. I pulled the belt and tried to start it with the alternator wires connected, AND again with them disconnected, but nothing changed. Also, sometimes the starter will turn for a second, then stop turning over, even though I haven’t released the key from the start position. No matter what, it will not start UNLESS I hook a battery charger to the vehicle and set it to 12v - 125Amp start, then the vehicle will turn over and start on the first try. The battery measures 12.4V at the posts with a meter, and I have installed a new battery, but nothing changes. I am getting 12.2V at the fuse box in the passenger floorboard. I’ve tested the grounds at the PCM, the main ground on the battery, and the engine block grounds as per ALLDATA, but all were in spec. I replaced the PCM and paid a guy to come to my house and program it. The part number for the new PCM I received was different than the part number for the one that’s on it, but I called the local Ford dealership and they said it should work, but who knows. Either way, it didn’t fix anything. Here’s what all I have replaced:



Battery

PCM

Starter

#5 Fuel Injector

#5 Coil



When I drive it down the road, it runs normal for a while, then the security on the dashboard will come and the transmission will drop into neutral, the engine revs up, then it shifts into gear, shifts into OD, and runs normal again until the next time the security light comes on. Please help! I have a video of it doing that driving down the road. Anyways, I'm not sure where to go from here! Thanks in advance for any help, this one is making my brain hurt lol

The video of it acting up driving home was too long to upload here, but here's a link to it on YouTube. Watch in the center of the dash when the security light comes on, then the RPM's shoot up.

 

[stamp11127]

Welcome to the site.

Since you are a tech, voltage drop test the positive and negative side of the high current starter circuit and negative chassis ground circuit. Max VD per circuit is .5v
Battery cables & terminals are suspect.
Chattering relays are from low voltage.

 

[1955moose]

Corrosion in the cables is a common problem on these vehicles. It sounds like one of the battery cables is so corroded, it's messing with the Pats theft system. That would explain the flashing dash light, and starter solenoid hunting for power, and clicking. Your wife's SUV thinks it has low voltage, when it doesn't. That also would explain why it fires and runs when you charge the battery. Let us know how the voltage drop test pans out.

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[Yupster Dog]

while you are testing like Stamp said. I would move the cable around(because they can be corroded inside the insulation) and check both positive and negative battery cables from one end to the other.

 

[TobyU]

Yes, start cleaning connections. Battery, at starter solenoid, ground battery cable and other grounds etc. then start pulling maxi fuses is fuse block and look for corrosion of signs of bad connections and heat build up.
Sound like you are losing power to ecm/theft system or other engine control fuses/circuits.

 

[MrGoodwrench]

Thanks for the fast response guys, I really appreciate it! I've been thinking it was a ground problem or voltage issue, but haven't been able to track it down yet, and I knew it was best to ask the guys that work on these everyday! I'll do the voltage drop test and check the battery cables when I get off work this afternoon, and check back in with what I find. Thanks again for the fast responses.

 

[1955moose]

Do your guys at work razz you for driving a Ford?

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[MrGoodwrench]

Hahaha I don't work at the dealership anymore, but other than me, very few of our techs actually drove GM products. Of course the sales team all drove brand new "demo" GM vehicles, but none of the guys that actually worked on them everyday really did. Honestly, I wouldn't have gone out and BOUGHT the Expedition in question...it was basically given to me, but I really haven't had any complaints out of it until now lol. I have always driven GM myself, currently have 4 GM products at home. Anyways, most of my work has been on GM products, and I've never had anything act quite the way this Expedition is acting, so I knew you guys would know these things better than I do and would have a pretty good idea about what the common issues are with them. Tried google, but didn't come up with much. Anyways, I think you all are right and I'm going to start testing for voltage drops as soon as I get home from work.

 

[1955moose]

Just remember when one of your four Chevy's breaks down, it's usually a Ford that tow's you home. A big ole F350-650!

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[MrGoodwrench]

You silly moose, Chevy's don't break down! Tow trucks are reserved for Mustangs leaving car shows LOL!