So I found this forum and liked how everyone was so I wanted to join and hopefully get some help because I am struggling.

I have a 85 Bronco 302 5L V8 EFI, and around 170,000 miles.

Around 4 months ago I had some wiring problems when the engine got wet smoke bellowed out from the drivers dash. I took to it my brothers mechanic and he told me I had some exposed wiring and my ignition switch was shorting out. Then 3 weeks ago while traveling down to see my friend and ran out of gas right before I was about to pull into a gas station. The reason I mention this is because I have never let it run out of gas and these things are the only things that have been different in the last two years of owning it.

About a week later we decided to go camping and as I'm heading up the hill the Bronco stalls out. After cooling down for a hour it starts up again, so a friend says it's vapor lock. I continue to have problems with it, it runs "better" at night when its cool, but this has never happened before even last summer. So my other friend who used to be a mechanic (because I'm new to working on a vehicle) says I should replace the air and fuel filter and maybe that will help and they're easy things to do. Also suggested I should put sea foam in the gas tank. So we replace them and now the truck sputters, and chugs from starting and then stalls out after 15-20 minutes of driving. We did a radiator flush and changed the thermostat because the truck's temp was all over the place, and it has fixed that problem. We replaced the spark plugs, distributor cap, and rotor.

Now after some research I've come up with a few options with my friends help.
1. Clean the injectors
2. Change the fuel pump
3. Add in a secondary fuel pump

Beyond that everyone seems to be lost on what to do. I know it's hard to track down exactly what will fix but if anyone has any other ideas or had any experience and could share some wisdom I'd be happy to be done with this problem.

** Also right before and when it's stalling you can hear a electronic buzzing behind the dash on the drivers side that doesn't sound like a steady buzz but almost studdering. bzzzz-zzzzz-zz-zzzzzz-zzz.**

 

the stalling sounds like a bad TFI module. this is the grey plastic deal thats sitting on the side of the distributor. when they get hot they will cause the motor to die.

check the fuel pressure with a gauge. it should be 39psi with key on engine off and with engine running.

what brand spark plugs did you use. make sure your plug wires are routed well and not crossing each other. I also suggest changing the fuel filter since you ran it out of gas that sometimes allows the crap in the tank to get picked up.

also pull codes. www.fordfuelinjection.com has instructions and additional info i suggest you read.

 

Wow, I never would have had any clue that could be a problem. I know exactly what you're talking about because it's right in the way when you're trying to get the bolts out of the thermostat housing. Checked prices and only a $38 fix well if you don't count having to buy the wrench for the screws. I'll be picking up one this friday and I'll make sure to post if it fixed the problem or not.

On the fuel filter we did replace that a few days later after I ran out of gas and it was uhhh well I'll just say black, but that really doesn't describe what it really looked like or do it any justice. Not sure of the spark plugs, my buddy picked them up and started putting them in for me while I was at work and when I showed up to finish I didn't really pay attention at the brand. I have the boxes still in the front of the truck so I'll check. The wires are routed well I know that.

 

our fords like regular copper autolite or motorcraft plugs. anything else tends to not play nice. and the fancy plugs are a waste of money and provide nothing on our engines.

 

Yeah they were just the motorcraft copper plugs

 

Replace whole distributor, or rebuild. I went thru this already with my 1990 DonKo

 

I hope it's not that bad, I really don't want to have to replace the whole thing right now.

 

Pull codes. KOEO, CM, KOER. The CM is the continuous memory and will "tell" you if the TFI ignition module on the distributor or the stator in the distributor failed. Check for a bad ground on the stud on the fender next to the battery.

If the codes show a PIP failure you may be better off replacing both the distributor and the ignition module as they have about the same failure rate. It sounds like the ignition module is on the distributor and not on the fender as in later models. Get a little tube of white paste from Radio Shack to transfer the heat, apply it liberally between the ignition module and the distributor if you can't find an upgrade kit to move it to the fender well.

 

Ok so changed the TFI and still stalled out. It did eliminate a lot of the sputtering that was happening before the truck stalled. Taking it to autozone this weekend to have them pull codes. Hopefully I can figure this out.

 

If it stalled going down the highway using more gas it could be the new fuel filter clogged if the gas is really bad. You mentioned the last filter change was nasty. I do not like 10% ethanol as that 10% goes bad in two weeks. Ethanol absorbs more moisture. Add Heet to the gas if the Bronco is not your daily driver.

Is your CEL check engine light working when you turn the key on? It is your friend if it comes on while driving. Check the continuous memory then.

Again, check grounds. Disassemble, clean and double check the ground stud is not turning in the fender next to the battery.

When you get the codes write them down for all three tests KOEO, CM, KOER. Right now CM is what I would be most interested in. Ask them to clear the codes so you can see what has changed with the new ignition module the next time it stalls.

I fought stalling a year or so.

After fixing mine I had a once in a lifetime opportunity to hunt in South Africa. Heading out early on the three hour drive to the first airport the Bronco stalled. The Atlanta to Johannesburg flight fills up months in advance so getting to the first airport in time was mandatory. I coasted into a parking lot, grabbed my little code tester and got 111 (pass) in all three areas. Yes, it started for the KOER. The ignition did not cause the stall. It ran fine thereafter and I made the flight. It has been fine for 10 months now. That stall must have been a fuel issue not ignition.

 

I haven't driven it much since it started getting worse. I kept finding myself in the wrong place when it would, so I parked it and have been working on it. When it stalls now it is just sitting in the parking lot. Basically you turn it on and it will run for about 15-20 minutes then starts acting like its out of gas and then dead. Some times you can jump in and start it back up only to have it do it again a minute late, other times it doesn't want to start up again for awhile usually an hour.

I'm trying to figure out how to get it to a checker or autozone as the closest one is about 20-25 minutes away. I'll update when I figure out the codes.

 

As you know, you can get the codes with just a little piece of wire. IMO the $35 digital code reader eliminates the guessing for someone impatient like me.

 

have you checked the fuel pressure at the rail yet?

 

I haven't, we looked for the valve but couldn't find it. Looked it up in my chilton and all it talked about was the inertia switch. I'm kinda stuck right now with what I can do because money got tight again. When payday comes around we're going to get it down to the closest checker and get it checked out maybe replace the fuel pump who knows after that.

 

the shrader valve is on the fuel rail about middle of the lower intake driver side. also pull the vacume line off the fuel pressure regulator. if gas is present in that vacum line the FPR is your issue.