My friend has a 1987 Bronco II that ran fine until one day riving started to jolt a little then the next day went to start it and it will only run with the pedal to the floor and then very rough. It is flooding out horribly and filled two of the cylinders with gas. Would it make since that the ignition module has gone bad versus two injectors at the same time. How hard is the ignition module to change on this.( havent looked at it yet cause its still at the shop they took it too but the shop is way to expensive to even look at it) If not any of this stuff any ideas. Thanks

 

That doesn't sound like the ignition module, and I would agree that one wouldn't expect two injectors to go at the same time (though if they are on the same side, it could be one bad wire grounding out causing the injector to stick open. I wouldn't completely rule out injectors at this point).

One common failure mode for the fuel pressure regulator is for the diaphragm to rupture, allowing unmetered fuel into the intake. If the hole is big enough, it will flood the engine. 1st thing I'd do would be to run the pump, then take the vacuum line off the of the FPR and see if there's gas in the vacuum line. Gas=bad FPR. If there's no gas, the next thing I'd do would be to put a fuel pressure gauge on it and see what's happening.

 

Then using a noid light, injector by injector you can see if they flicker or stay on. The engine will run on only 5 cyl, just do not floor it. Start with #6 and see if you have a wiring problem to the injectors.

I agree, unlikely only two cyl would flood if the module was bad. Possible one inj. was bad and marginal, then another went completely which killed the engine. I had that happen on a customer's 4.0 Cherokee.

 

I checked the FPR and that indeed had gas in the vacuum line. I only looked at it for a minute on my way to class but it didnt look to hard to replace. Is there anything special I need to do when replacing it. Also when I go to fire up the truck after do I need to worry about the extra gas? Thanks again for all the help.

 

For what it's worth, I just replaced a fuel pressure regulator and it fixed a lot of the problems that I had.

My idle was irratic, reving up and down.
It stumbled horribly when it was cold.
it would start to buck like a donkey at about 35 mph when cold

You would have thought it was running on 4 cyl.
Plus my fuel milege was horrible.

It seems to have calmed down a lot since the fix.

It helped that the weather changed here, when it was warmer the syptoms were not as harsh, when it dropped into the teens is when
things started to become noticeable.

Typical Ford cold natured issues.....

 

That is exactly the same as my friend is experiencing until just recently when it wont run at all hardly. quite a bit of gas in the vacuum line. How hard is it to replace. Is it just the two lines and two nuts that I see? Also to depressurize the system can i just bleed out the valve on the fuel rail? Napa has an FPR for $28 but everywhere else it is about $70. Is the cheap one probably not the correct one. Thanks again

 

Honestly it's hard to tell? Most of the ones I've bumped into run anywhere from about $80 bucks and higher?

Granted they all look the same for the connectors. As for depressurize? If you find fuel in the vacuum line, and the truck has not been started in a while? Chances are fair there won't be any built up pressure. (it'll all find it's way into the intake via the vacuum hose)

Looks fairly simple enough, but that's where things can get complex LOL. Word to the wise? You'll most likely need a special tool to remove the fuel line from the regulators hose. Probably has a "Garter" type spring that can be tricky. Try to stay away from the plastic type tools, they have one tool that will service 4 different sizes. The tool is made of metal and is not to hard to work with. I'm not sure how easy or hard removing the feed line from the regulator will prove? As it looks like it's an extreme tight fit onto the regulator.

You can of course try the $28 and see how well (or not) it works. I'd personally spend the extra money for a high quality one. (I hate doing the same repair more then once)

Haynes manual time for the torque specs on the bolts that retain it, and for any hints or tips to make the job go easier. Have a care with that O-Ring!! Last time I had the injectors out on ours? Had a couple of O-Rings tear slightly while installing them. It's gotta be installed 110% correct, otherwise you'll be taking a fuel bath.

S-