Have struggled with this problem for months, truck dies and leaves me stranded requiring a tow. Most recently after a 150 mi drive at 65-70 mph, the motor just dies as if out of gas.

pleaase help

 

It sure would help if we knew what truck you are driving
Tape a fuel pressure gauge to the windshield for the next test drive

 

Sorry, good point!! 1996 Bronco 5.8L motor. as problem is persistent, beyond my capabilities, it has been to two mechanics. Long story short short, fuel filter, fuel pump x 2, Ignition model, distributor, cap/rotor, wires and PCM have all been changed. A new wire running to fuel pump was also changed as I was told the voltages where off. Someone also said the 2 wires on an o2 sensory were reversed so that was changed, new EGR replaced. The last problem occured about 7 months ago and all was well until I drove it to my Navy drill site 150 mi away. While on the weekend, the truck died in the parking lot twice while backing up but started again immediately. I drove home Sunday evening and made it 145-150 miles when it did it again. The tach drops to 1000 rpm, the speed declines, the motor coughs and sputters, then ultimately dies. After it dies, I can turn on ignition and hear the fuel pump run, but truck fails to start or starts but dies immediately. Typically, the following morning the mechanic will call and says it starts right up and runs fine.

 

Now that it is an OBD2 1996
I'd check the codes along with the fuel pressure gauge taped to the windshield
Were all your new parts Ford?
If not, I would suspect a few of them may be faulty like the distributor or ignition module
Better IMO to replace the stator in your original distributor than replace the distributor with a China model
I suspect a fuel problem is why the first step for me would be my fancy long hose pressure gauge

 

In general, unless the problem is obvious (which is apparently not the case here) the first step in troubleshooting an EFI engine is to read out any fault codes. '96 5.8l with an AT will be OBDII, but with a MT will be OBDI (though I don't think that there were any 96 5.8l Broncos made with a MT).

FWIW, the symptoms sound a lot like the PIP pickup in the distributor, which which will throw a fault code (and might cause the PCM to stop firing the injectors, making an ignition problem look like a fuel problem - which is just one of the many, many reasons to read the fault codes before spending a penny and 'fixing' stuff that isn't broken). That you've replaced the distributor once already would imply some other problem, but I've had a brand new Motorcraft DU-50 PIP sensor (which should be the same one used in a 96 5.8l) fail after only ~100 miles.

 

Manicmechanic007,
Thanks for reply, please keep in mind, I'm translating only what has been told to me by the mechanics as this problem has become way over my head...and theirs too. As we speak, the truck is sitting at the mechanic shop now.

Yes, the mechanics have all checked the codes each and every time this has happened. I can't tell you here what those codes were, I have always been told they were nonspecific and not helpful in diagnosing this problem.

New FORD parts? I have no idea where the mechanic shop's buy their parts from, what the brands were, or what country of origin manufactured those parts.

I recall a discussion about the ignition module being either BLACK or GRAY, and its had two of one color, and one of the other but now I do not recall which color is on it now.

I have always suspected this to be a fuel problem as well, HOWEVER, what ever the problem is that causes the fuel pump to stop, then start again after the truck cools down is much more likely to be electronic right??? Nobody has ever told me these fuel tank mounted pumps have issues with working when they are hot and work again when they are cool. Of course, maybe they do, I don't know.

I like your idea of the remote fuel gauge, perhaps I can rig something up like that for the future, as my confidence now is some body finding the problem is very low. Once this happens again, if the fuel pressure remains normal, we I identify a problem as being electronic...what could it be?
If the fuel pressure drops to low, or zero when the truck is symptomatic, what would cause the fuel pump to do that, they work normally again after cools overnight?

OBTW, the truck is on its 3rd fuel pump in under 5 years, because different people have diagnosed bad fuel pumps. Again, no idea where these fuel pumps where made, or by whom, or what country but it is out of the ordinary even for an off brand china made pump to require changing evey 12-18 months.

thank you VERY much for your comments, hope you can advise further.

 

Blue/Green,

Thanks for your reply.

Yes, the truck is OBD2, Yes, both different shops have read the codes, and the mechanics have told me they have been non diagnostic, or there is no recorded code. I recall each time, a code for the 02 Sensor always pops up and the 02 sensors have all been replaced, several times. I have also been told that these early OBD2 computers are not like the qualitiy of today, and many times, do not diagnose the problem, again, I don't know.

The distributor replacement done recently (7mo ago) never gave off a code to suspect anything in it was bad. It was a "hail Mary" hoping to replace something that was intermittently bad that we could not identify. Same idea with the PIP computer in the truck.

 

I would not jump on replacing another fuel pump right now either
I sure would drive it around with a pressure gauge on it
What are the O2 codes? Lean codes? Maybe get your own cheap scan tool that reads PIDS and check a few
Dying after driving 150 miles only?
So, you mean, if you brought it to me and I drove it around for a week around town, It would never die on me?
I would put test equipment on a few circuits (like the fuel pump power wire through the tank selector switch) (put a test light on that fuel pump wire)
Same for the ignition coil power feed, put a test light on that circuit that you can see while driving

 

manicmechaniic,

Good morning and thanks for reply.

1. I like your pressue gauge idea. When I get the truck back from this lates break down, I will do that. The truck is currently at the mechanic shop after being towed there from my last break down on the side of the highway.
2. Could not tell you the actual codes as the mechanics read them, not me. I have ordered an OBD2 code reader and will be prepared to read them the next time this happens, unless the mechanic figures this out and actually finds the culprit.
3. Yes, this episode occured at about 150 mi drive time. Other episodes have been less, 20 to 50 miles. I never know when it will happen!!! This episode is the first in over 7 months since last visit to mechanic shop. The farthest I have driven it for lack of confidence the truck will get me to where I'm going, and it has proven to be exactly that...unreliable. All the previous episodes have happened around town, yet all have required a wrecker to get the truck to a shop.
4. Your guess is as good as mine. You might drive it for 7 months around town as I have and never have a problem, or you could drive it tomorrow, get it warm, and have the same issue happen. I can tell you with certain, ALL these episodes are symptomatic in the same way. The truck is running fine, then suddenly, the tach drops to 1000 rpm or less, I press the accelerator pedal to recapture speed but nothing happens, the motor then dies and I coast to the side of the road.
5. HELP...what test equipment would I put on the fuel pump wire?? Where on the fuel pump wire? How and what on the ignition coil power feed?? You kind of lost me hear, sorry!!!!
6. I'm replaced my Bronco as my daily driver simply because the problem has gone on for so long, no end in sight, and AAA I'm sure is getting tired of towing me all over San Antonio.
7. Again, the truck is currently at the shop in San Antonio, Sirianni Automotive, as that is where it was towed to on Sunday, May 19th, while driving home from my Navy drill weekend in Corpus Christi.

 

You would put a test light on the actual power wire for the fuel pump at the sender itself
Bitchy and you need long test leads but it will tell you if you are loosing power to the pump
I am quite certain that you are losing fuel pressure if the tach stays at 1000 when the problem occurs
Hopefully the shop in San Antinio can figure something out
We used to drive cars home and at lunch all the time at the dealer
I had a Super Coupe at my house for 5 days (figured it out for the guy)
Best of luck
About a scan tool
I have 4
One that costs 40 bucks now, is better than one that cost 200 a few years ago
Get one that will read PIDS
That way you can check your fuel trims and watch your oxygen sensors switch
Not much goes wrong with 96 Broncos
The MAF sensor and the O2s need to jive
You can check a few pids against reference tables if you get a decent scan tool
This is your actual scan tool for a 1996 Ford Bronco, but they were 5500,00 back then and required support

 

Manicmechanic,

1. Why would it be losing fuel pressure?? as in there is leak in the fuel line, or something stopping the pump from creating pressure?

Yes, I hope so but my I've lost faith. This problem has gone on a very long time, I've been stranded 5 or so times requiring a wrecker, and since its above my level, I send it out to the experts, who consistently say its fixed, but then its not. You know what I mean??? My god, must I junk my Bronco because of this?? Frustrating but also, I have no faith in driving it anywhere for leaving me stranded again, as time has shown it will do. Should I take it to the Ford Dealer????

Want me to ship the vehicle to you and let you drive it around?? Joking....not joking.

I ordered a scan tool. Not sure it reads PIDS, but when it arrives, if it doesnt, I'll send it back.

Thank you for all your help and suggestions!!!!