Stalls when starting out

[ff lc freak]

Hi all,

I have a problem with my 94 Bronco. It is a 351 with E4OD and 140k miles pretty much bone stock. Yesterday, out of the blue, it developed a stall when starting out. After start up, when I put it in any gear forward or reverse, after driving 20-30 feet, the engine stalls / dies. If it doesn't die, I can drive on normally with no problems after that. But once I shut down (or it dies) and restart, it will stall out once (and only once) and then drive normally. If I keep my foot on the gas, it will usually keep running and then drive fine with no other problems. It does this on every start up. When I start it up and let it idle, it runs fine. If I rev it up, still no problems. But once I start moving it stalls/dies.

I checked for codes and got a 111 for KOEO, KOER and CM codes. So, no codes thrown. This afternoon I was driving on the highway at 60 and turned on my headlights. Immediately, the engine died. I turned off the headlights and the engine restarted. I tried a couple more times just to be sure and got the same result. I got home and tried it while sitting in the driveway and the engine immediately dies. It sounds like turning on the headlights shuts off the fuel pump. When I shut off the headlights the fuel pump turns back on. During all this, the voltage doesn't drop or spike. It stays around 13-14 volts (roughly - gotta love Ford gauges with no numbers).

So, any ideas? Is it a short? A bad sensor? I checked all fuses and there are no blown fuses.

Any help would be greatly appreciated.

Thanks!

 

[fordsohc46]

i would ck battery voltage after start up and when you turn on lights with an ohmmeter to be sure you are not losing voltage. other than that not sure where to go. sorry.

 

[Seabronc]

That gauge is a idiot light with a needle. Check the voltage at the battery with a volt meter. Check the connections and cable condition from the battery (+) and (-) to their first point of connection. Remove the cable from the connections and clean the contact area, including at the battery post. A lot of freaky problems are caused by bad ground connections.

Good luck,

>-

 

[89Bronco58]

I must agree with Seabronc. Fords and grounds are a huge headache when things go wrong, but to me, it sounds like when you hit your lights it may be killing the spark in some way, since it dies so fast. Bronco's have 2 fuel pumps on most EFI models, and it would still run for a few seconds or so even with the fuel pump off. Thats why it sounds like a spark/electrical issue to me, but i could be wrong. Trial and error ( or a shop ) is about all you can do, good luck!

 

[ff lc freak]

Well, I seem to have fixed the issue. After I realized that turning on the headlights cut out the fuel pump (I found this out at home while testing things out), I started chasing electrical problems. I'm still not sure what fixed it. However, I cleaned all my grounds even though they were not dirty or corroded and made sure they were tight. I know grounding issues can cause lots of problems so I thought I would start there. In doing that, I had the battery disconnected for awhile. When everything was hooked back up, it ran fine.

So, my two theories are:

1) It was a bad ground. Like I said though, none of them looked bad or corroded. Who knows?

2) A glitch in the computer? I don't even know if that can happen, but after "rebooting" it runs fine. Anyone know if that can be a problem? Most of my experience working on cars are the carburated kind. Like I said, this started in the middle of "running errands". It ran fine for probably 8 startups earlier in the day, and then "bam!" I was having problems.

Weird.

On the bright side, everything is running great again. Thanks for the suggestions everyone.