ok i really need help this time. please help

[famousguy_fsas]

k. i have 86 5.0 efi. it ran fine till i took it through some crazy mud pits and now it has trouble starting. it starts right up when jump starting and will run fine when driving. we tried to test the altornator and battery at autozone but my truck would not stay at 2000 rpm for ten sec like it needed to for the test. the rpm would go all speratic and then the truck would die and the rpm would fall but to 6000 and not to 0. i drove for a bit and afterwards would stay at 2000 rpm. i think but i dont know for sure cause my rpm gauge is messed up now. when in a high gear like just drivin it wont work but then when u give it gas and it jumps down gears like goes into over drive or something it works again but not right. if it starts from 0 it works but instead of being at 2000 where it would normally be it will be at 4000 even though the engine is not. but right now the rmp guage is working backwards it starts off at 6000 and goes backwards for my rpm. but still only works in a faster gear i guess. now that i think about it it might only be kicking in after a certain rpm i dont know. but ya its working backwards right now.

most of the time when i try and start it now it will try and turn over but wont like there isnt enough juice. we did test the battery and from what we could tell it said it was good.

also kinda random but yesterday when it wouldnt start after the mud fot thre first time. it wouldnt even turn over or click. had power but truck would do nothing. then a guy came over and said his truck did the same thing and all he did with his was slam the hood close and it worked. so we slamed mine and it started up. haha. but everyother time that it wouldnt start it would at least try. please help.

also right now it wont do anything when i turn the key so im gonna try the hood slam thing. if it works that would make me think loose wire but still every other time it would try so with the whole rpm thing something more has to be wrong

 

[73coupe]

pull the starter see how much mud got into it

start cleaning every connection you can find

havent been mudding in my Bronco but do it frequently on the ATV

even with water resistant connectors mud water and other things have a way of getting in

 

[famousguy_fsas]

to my knowledge mud cant get into the tarted. its all enclosed in. plus as soon as i jump start it right now it starts right up so its not my starter.

 

[Yardape]

to my knowledge mud cant get into the tarted. its all enclosed in. plus as soon as i jump start it right now it starts right up so its not my starter.

On the contrary, that tells me that it could be your starter. When the starter goes it slowly demands more power. Giving the illusion that your battery doesnt have enough voltage. When you hook up another battery like in a jump start, you are providing the extra power your starter wants and it starts fine. And yes mud can and will get into your starter. All your other sound like bad ground or dirty connections. And finally, after reading the first line of your post, even though you said you dont mean to be rude I found that extremely rude. If you want help keep it friendly and do away with the demands. I wasnt going to respond to your post just because of that but you have been a good contributor in the past so I decided to help. Please remember we are all guys just like you that share a love for Broncos.

 

[famousguy_fsas]

sorry. its just been a bad day. i guess i worded it wrong. what i ment is that i allready checked simple things like wires and stuff. its not the starter cause the batt actually is low. is only at half the voltage and when i drive at night everything is dim. head lights dash lights. everything. so tomorrow im takin out the batt and alt and have em both tested since my truck wont work right to test em on the truck. im guessin its one of those two things. but would a bad batt or a bad alternator cause the rpm guage malfunction that im haveing? and sorry i was rude at first. ill take that line out. just a really bad day. thanks all

 

[Broncobill78]

Well, since you seem fairly determined to pull the battery/alternator go ahead & bring them down for testing. You might also have a problem with the voltage regulator. If the truck isn't starting any more easily then I'd suggest cking the starter (if you're have the parts place ck the batt & alt you might as well pull the starter & have it ck'd at the same time. The starter is *not* hermetically sealed and you can indeed drown one /emoticons/[email protected] 2x" width="20" height="20" /> ). Let us know what you find

As far as your tach goes, more info would be helpfull. Is this a factory tach that just suddenly began acting this way after an afternoon of misadventure , is it an aftermarket that has never worked correctly or did it come with the truck and you just don't have a clue to it's history.

In general it probably wouldn't be a waste of your time to clean the engine compartment thoroughly. clean & inspect all your connections and while doing that you can add a bit of dialectic grease to all of them to improve electrical contact AND help water/mudproof them.

By the way, is that a multiport engine or CFI(throttle body EFI) ?

 

[famousguy_fsas]

the tach is the stock one and it has always worked just fine until my mud trip the other day. my dad said that my tch is is hooked into the distributor cap . and thats where it reads the rpms so to check that. but the reason im so determined to pull the batt and the alt is cause my batt is only at half charge so that tells me one of those two things has to be bad. im also positive its not the starter cause as soon as i get that extra power its just fine. whether i jump it or put another batt in from my girls truck. the big thing its doing now is once i start it it will run fine and ill drive for like 2 min and then then just die and ill roll to a stop.

 

[Broncobill78]

Well, ok, not to put *too* fine a point on it but you might want to reread YardApe's comment. I'm not discounting a possible problem w/the alt (or voltage regulator, don't forget about that particular widget) but what you're describing is a classic failure mode for the starter. As the starter starts to die it's internal resistance increases dramatically. It usually SEEMS like a low voltage problem but the fact is that the starter is *drawing* a lot more amperage. When you supply the additional amps (like when you hook up jumper cables) you have enough juice to spin it & start the truck and the common misconception is that the battery or alt is at fault. Replacing the battery often works for a short time because the new batt has more cold cranking amps but the honeymoon usually doesn't last for long. Maybe in this case it IS the battery/alt but I don't think anyone here will be surprised if a new starter becomes part of the solution. The starter itself isn't really waterproof & remember that the snout of it is open. If you get that deep in water/mud you can get a lot in it thru the inspection cover on the bellhousing which is right next to the starter snout.

Once more, just out of curiosity is the engine multiport or throttle body injected (multiport has the large upside-down "J" looking intake while the throttle body EFI looks a lot like a carb'd engine) ?

 

[Yardape]

Its the same efi as the newer Broncos. It really sounds to me like bad ground connections. Start your truck, unhook the neg battery cable. If the truck stays running then your alternator is working. Also if your battery isnt getting a full charge try removing it from the truck, hook it up to a battery charger and give it a full charge. Sometimes the battery wont take a charge until you do this. Try my first suggestion though

 

[famousguy_fsas]

thanks everybody. i figured it out. it was my alternator. i tested both batt and alt and the batt was good but alt failed right away. i knew it was bad the second i took it out cause i could spin it and hear the crapped out bearings. i just killed it with the mud. im just used to my chevys with the alt being on the top of the engine and not the bottom. but i still love my bronco. just need to lift it is all. the only reason i never thought it was the starter was cause my batt was only at half charge wich told me it was either that or my alt. but i replaced it and now everything works great. no more mud till i lift. thanks everyone for all the help. i love this site

 

[Broncobill78]

Cool, glad to hear it's fixed. Does the ammeter in the dash work ?

 

[Broncobill78]

Its the same efi as the newer Broncos.

Ok, thanx. I know the 85's were CFI & the 87's used multiport but wasn't sure which way the 86's went. Just a curiosity thing /emoticons/[email protected] 2x" width="20" height="20" />

 

[muddinlate86]

i have the same problem with my batt.its anew batt and alt.but at night with the lights on im at half volts.arnt the reg built in to the alt.?i no my 79 wasnt but thought the 86 was i have thel 60amo alt with the two pigg tails on it .thanks for any sujestion.

 

[famousguy_fsas]

muddinlate86. if u have the same 5.0 multiport efi i have then urs has a internal regulator. you can tell by looking at your alternator. if it has the internal voltage regulator you will see it on the back. it will also have 2 plugs. one on the side and one on the back that plugs into the regulator. the regulator will be a little black box on the back that takes 4 screws to get off.

if you have the external regulator you will know by not seeing the regulator on the back and will just have wires that connect to the back. if you have the external one you will find the regulator located near the front of the engine compartment either on the radiator support or the front of one of the fenders

are you running any extras on ur bronc? ie amps subs extra lights?

 

[muddinlate86]

hahahahaha funny story.........yes.but the problem lies some where else i have just hokked up the system and the problem has happend since ive had the truck.the funny part is when i turn up the stereo the gage goes up with the power of the base unlike normaly it would drain and charge tis goes the opposite.?>? but5 my truck has started to do the"whats rong now"thing and when i sit at idel for a min or two it just dies.no warning or nothing but starts back up and is good for another round. any ideas?????????????????

 

[Broncobill78]

? but5 my truck has started to do the"whats rong now"thing and when i sit at idel for a min or two it just dies.no warning or nothing but starts back up and is good for another round. any ideas?????????????????

might be worth reading this thread

http://broncozone.com/forums/index.php?showtopic=17293