HELP!!! --- Long post on random car stalling.

[RRRoamer]

Have you tried re-seating the fuses under the hood? I had a recent issue that was fixed this way (engine would die and I got the "check charging system" message; never any codes and it was intermittant).

Some of them, but not all of them. It's quick and easy to do, so I'll do that this morning before I head out. Thanks for the suggestion.

 

[RRRoamer]

Well this is interesting. Today, before I took the car out, I pulled out every single fuse in the BEC, visually inspected them for discoloration or corrosion and reseated them.

While I had them out, I also put them in all facing the front of the car....

I also pulled out each of the relays and reseated them as well.

A quick drive down to the bank, then I was going about my rat killing. But the car stalled before I even got it backed out of my parking spot at the bank!

Now, the reason this is interesting is because 1) the car had been getting better with the colder weather and 2) this just changed the whole MO of the car! Granted, it was for the worse, but it WAS A CHANGE!

The car died on me about eight times before I could drive the two blocks to a local Autozone, where I bought myself a full fuse kit and proceeded to replace every single fuse in that box that might possibly have anything to do with the electronics (PCM, SJB, ignition, ignition switch, etc.).

The next test drive was also very informative, even though I did have a couple more stalls. Mainly, because I went about three miles without a stall, when before I swapped out the fuses, I was stalled about every 300 feet.

So, just so you understand, I do not think the problem lies in the fuses. I think the problem is underneath in the BEC itself. Now I have something I can tear into and put under the proverbial microscope.

Please Lord, let this be the problem!

 

[05stroker]

Well this is interesting. Today, before I took the car out, I pulled out every single fuse in the BEC, visually inspected them for discoloration or corrosion and reseated them.

While I had them out, I also put them in all facing the front of the car....

I also pulled out each of the relays and reseated them as well.

A quick drive down to the bank, then I was going about my rat killing. But the car stalled before I even got it backed out of my parking spot at the bank!

Now, the reason this is interesting is because 1) the car had been getting better with the colder weather and 2) this just changed the whole MO of the car! Granted, it was for the worse, but it WAS A CHANGE!

The car died on me about eight times before I could drive the two blocks to a local Autozone, where I bought myself a full fuse kit and proceeded to replace every single fuse in that box that might possibly have anything to do with the electronics (PCM, SJB, ignition, ignition switch, etc.).

The next test drive was also very informative, even though I did have a couple more stalls. Mainly, because I went about three miles without a stall, when before I swapped out the fuses, I was stalled about every 300 feet.

So, just so you understand, I do not think the problem lies in the fuses. I think the problem is underneath in the BEC itself. Now I have something I can tear into and put under the proverbial microscope.

Please Lord, let this be the problem!

I had all kinds of elec. issues that were solved by replacing the Buss fuse box . The problem was the terminals in the fuse panel had been probed for testing and finding 12v power ect .. That being said the connecttions for the fuses are spring loaded and probing them can cause serios damage . In my case it was the fuse terminal to the SJB and the fuse shook to the touch like a babys loose tooth .

 

[Darth Stang]

Hey!! This is a real long shot, but when i first got my Stang in 2005, I had a real bad stalling problem. it would die on me for no reason, this sounds similar. After a tow to the dealer, some very clever technicians found that the relay which controls the fuels injector power had a broken pin. Whenever the pin went out of alignment, it would kill the engine. It would always resettled and work, but basically a 2 dollar part was killing my $33K car. You may be in the same boat, so check the relays for your fuel injector power!!

Edit: I checked one of my old posts and here it is....Fuse box circuit 1118 , controls all power to fuel injectors.

 

[RRRoamer]

That is interesting... I just dug through the schematics and it appears the fuel pump relay controls not only the fuel pump, but also power to each of the fuel injectors (the PCM grounds them to "fire").

I had previously ruled out the fuel system as a problem because the fuel pressure stayed mostly steady during the stall events according to the data logs. But, with the injectors AND the fuel pump on the same circuit, they would both shut down at the same time and the check valve at the pump end would keep the fuel from leaking back. Because this is a returnless system, the pressure would not bleed down over time (well the short time between it dying and me restarting it) like a normal system would either, so the pressure would remain fairly constant.

That is DEFINITELY something to dig into the next time it stalls. It is a very easy test too: when it stalls, pull over to the side of the road and swap the fuel pump and AC clutch relays.

If the problem stops, then I have FINALLY found my culprit.

If not, then I'm on to round 27 (or is it 36? I forget...)!

Thanks for the info!

 

[RRRoamer]

DarthStang,

Can you believe it? I think I FINALLY found the root cause of my stalling problem that has been going on for the last year!!!!

Your suggesting about the fuel pump relay pointed me in the right direction. Right after Thanksgiving, I was doing some driving and it started to stall REALLY bad. When I finally got the car off the interstate to someplace I could safely open the hood, it was running so bad that I almost couldn't get the bitch to start. Just the engine shaking as it fired up was enough to kill it.

So, I popped open the BEC and swapped the AC and fuel pump relay.

Needless to say, it started right up like nothing had happened. I immediately drove her over to the Ford dealer that I had been working with (on the other side of town of course!) and it made it there with no issue. I ordered a new relay on the spot...

At this point, I THOUGHT I had this problem licked. But, of course, it died again on me a few days later. Thankfully, it only stalled once that day (instead of thirty or forty freaking times!), so I had to drop the fuel pump RELAY theory, but I was definitely looking closely at the BEC.

The car basically behaved itself for the next several weeks with only the occasional stall (maybe once a week or so). Today, it was a COMPLETELY different story! I was heading back home on I-40 when it started to stall. And it kept getting worse and worse as the minutes ticked by. Fairly quickly, I was over on the side of the road because I couldn't even keep it up to speed.

My first attempt at a "get the bitch home" repair was to swap out the fuel pump relay (no, I didn't really expect it to help, but hope springs eternal...). It made a TINY bit of difference and I tried to get going again.

I made it another half mile down the road before I was on the side of the road again. Cussing...

Now to the meat: As the car was totally fucked, I decided I would never have a better chance to dig around under the hood and track down what was causing this. If I didn't get killed by rush hour traffic on I-40, that is...

My first attempt at stalling it was to wiggle each of the three cable bundles coming in and seeing if the car died. The BEC sits kind of loose (it's only latched on with two plastic latches), so I placed my hand on the top of it to hold it in place before I started wiggling the cables.

And the bitch stone died!

I restarted it and this time I VERY carefully and slowly placed my hand on the BEC and pressed it down to hold it firmly in place. It was still running, so I started to wiggle the cable bundles to see which one would cause it to stall.

To my surprise, NONE of the cable bundles seemed to have any problems.

There were only two more cables going into the BEC: the main cable from the batter and a 10 awg wire that feeds my driving lights. It is bolted down right on top of the main power cable. When I wiggled the light wire, it died.

That surprised me because I only moved the cable about 1/8" and I was holding it about 5" from the end, so I wasn't putting very much pressure on the connector at all, not with a multistrand 10 awg wire... The wire has a fuse in it just up from where I wiggled it, so I pulled the fuse and restarted the car. A small wiggle on the wire STILL caused the car to stall!

At this point, I pulled the cover off and looked at the terminal plate when I wiggled the light wire. It BARELY moved as expected. I fired the car up and then slightly wiggled the main power cable as well. Once more, it stalled.

The next step was very interesting (not the least of which that it FINALLY got me back on the road!): I unsnapped the BEC from the bottom plate and then used my hands (on on top and one on bottom) to press the whole BEC/terminal block assemblies tightly together. After firing it back up, I did the tug and pull thing and the car did NOT die.

About fucking time! I now know EXACTLY where the problem lies in my car! After having a conversation with the cop who pulled up behind me right about this time, I was able to get home with no more stalling.

Once home, I pulled the whole BEC completely apart (unbolted the four connector blocks and power cable and completely removed it from the car). I dug into the rear most connector block to make sure the fuel pump connectors where still in good shape as I had soldered a wire lead to the relay output connector to power my wideband, so I thought maybe the problem was there. It wasn't. All the connectors and wires in each of the connector blocks looked perfect.

Of course, then I realized that the car stalled when the POWER distribution was wiggled and THAT bit is totally contained in the upper BEC itself. So, I made an attempt at disassembling the BEC (and failed). Each relay and every fuse came out before I realized that I had NO way to actually break that thing open without literally breaking it...

So, I restuffed the fuses and relays, bolted the car back together (yes, it DID start on the first time) and then called my Ford dealer to order a new BEC. $220 is VERY cheap money to keep this bitch from ever stalling on me again!

At this point, the CURRENT working theory is one of the metal rails inside the BEC that distributes power to the assorted fuses and relays is cracked. It normally is pressed together, completing the circuit, but when it warms up, it can be opened due to a mechanical shock, leading to the car stalling.

Once the new BEC is installed, the old one is going under the knife and I WILL find out what is going on inside that bitch of a part.

I love my car, but this stalling saga has had me dreaming about sticks of dynamite and C4...

If the BEC doesn't fix this thing, It's getting a damned carb!

 

[solaratomic]

I know you think this is an electrical problem, but have you changed the fuel filter? I just changed mine with 64K and found it to be very dirty (intermedate loss of power in 1st and loss of MPG). I figure the average GT has more fuel run tru it per mile than most vehicles. Just something to consider.

 

[05stroker]

I had all kinds of elec. issues that were solved by replacing the Buss fuse box . The problem was the terminals in the fuse panel had been probed for testing and finding 12v power ect .. That being said the connecttions for the fuses are spring loaded and probing them can cause serios damage . In my case it was the fuse terminal to the SJB and the fuse shook to the touch like a babys loose tooth .

Hmmmmmm........

 

[RRRoamer]

Hmmmmmm........

I know! Trust me, when I touched the BEC yesterday and the car died, I thought of your post!

On a very so slightly related note, if you want to do some serious probing WITHOUT damaging anything in there, you can lift the whole BEC assembly up from the base and then remove the plastic covers off of the four connector harnesses. You will then have full access to the BOTTOM of the pins and you can probe all day long without stretching or breaking anything.

Oh, and if you have to probe any of the other connectors on this car, one of the Ford techs that tried to help be diagnose this problem showed me a very slick way of probing the connectors: take a piece of somewhat stiff wire (I used a single wire from a Cat 5e cable) and wrap it around the head of a medium sized T pin. Those medium T pins are the PERFECT length and thickness to slip in to the back of the connector past the wire. It will wedge itself snugly between the connector and the plastic connector housing without damaging anything but making a great connection. This even works on the three large PCM connectors, you just have to remove the plastic cover first.

With a Cat 5e cable, you can have up to eight signals probed and then simply run the other end of the cable into the cab and you can hook up your meter (or whatever) to the pins as needed to measure what you need while going down the road. Combine that with a data logging meter and you can get a lot of data that you simply can't get from the ODBII port. WITHOUT damaging a thing!

And they will stay in place too. I had one connection to the TPS setup for over a week with no problems at all.

 

[RRRoamer]

I know you think this is an electrical problem, but have you changed the fuel filter? I just changed mine with 64K and found it to be very dirty (intermedate loss of power in 1st and loss of MPG). I figure the average GT has more fuel run tru it per mile than most vehicles. Just something to consider.

At this point, I am 99.99% sure it is an electrical problem in the BEC and not the fuel filter for a few reasons: 1) The filter was changed about 2,000 miles AFTER the first time it stalled last year, 2) I have data logged the fuel pressure and it is rock steady until the instant of the stall, 3) the worse stalling is caused by bumps and sharp jolts to the car, which shouldn't have any impact on a clogged fuel filter, 4) the stalls happen while accelerating, while coasting, while idling and while cruising and a clogged fuel filter should impact things worse during high fuel flow conditions and FINALLY, 5) the car dies INSTANTLY when it stalls, not the way a vehicle responds when it is losing fuel pressure. Oh, and I left out that the damn vehicle security icon flashes up on the dash during most stall events...

This whole thing has been screaming "electronic problem" since the first time it happened. I just can't believe that it has taken a YEAR to get to the bottom of it.

But, I really should change the fuel filter again. It is getting about due...

 

[05stroker]

I know! Trust me, when I touched the BEC yesterday and the car died, I thought of your post!

On a very so slightly related note, if you want to do some serious probing WITHOUT damaging anything in there, you can lift the whole BEC assembly up from the base and then remove the plastic covers off of the four connector harnesses. You will then have full access to the BOTTOM of the pins and you can probe all day long without stretching or breaking anything.

Oh, and if you have to probe any of the other connectors on this car, one of the Ford techs that tried to help be diagnose this problem showed me a very slick way of probing the connectors: take a piece of somewhat stiff wire (I used a single wire from a Cat 5e cable) and wrap it around the head of a medium sized T pin. Those medium T pins are the PERFECT length and thickness to slip in to the back of the connector past the wire. It will wedge itself snugly between the connector and the plastic connector housing without damaging anything but making a great connection. This even works on the three large PCM connectors, you just have to remove the plastic cover first.

With a Cat 5e cable, you can have up to eight signals probed and then simply run the other end of the cable into the cab and you can hook up your meter (or whatever) to the pins as needed to measure what you need while going down the road. Combine that with a data logging meter and you can get a lot of data that you simply can't get from the ODBII port. WITHOUT damaging a thing!

And they will stay in place too. I had one connection to the TPS setup for over a week with no problems at all.

I also noticed recently that the frigin fuse its self has places on top to for power . Look at the fuse there are two bare spots that can be checked for power. From what I understand this should only be donr with a test lght and not a volt meter . Something to do with the grounding or something likr that .

 

[solaratomic]

Just a thought, I had a F150 that would stall sometimes because of a clogged fuel filter. How come nothing seems to be simple on vehicles anymore?

 

[RRRoamer]

Three little letters: E.P.A.

 

[bigray327]

Bringing up an old thread...

RRRoamer, did you ever figure out the exact problem? My car started randomly stalling this weekend. Two days ago, I inadvertently bumped the BEC while doing something else and it came unseated from the bottom half. I hope I didn't screw something up.

Thanks.

 

[bigray327]

RRRoamer, did you ever figure out the exact problem? My car started randomly stalling this weekend. Two days ago, I inadvertently bumped the BEC while doing something else and it came unseated from the bottom half. I hope I didn't screw something up.

Figured out my own problem. The ground wire going to the radiator support was loose. After tightening that - and shocking the shit out of myself in the process - it's fine. Anybody know what that's grounding? The alternator?