New problem, possibly a short?

[77broncodriver]

Hopefully this is the last question for the week, I got mostly everything done on the bronco then took it for a drive and it bogged, backfired, died and the battery drained.

Got a new battery and it started right Ho but when I connected it it sparked a bit and I think that means there's a short but I don't even know what to check for or anything.

It also runs pretty bad and every sensor is new in the mustang efi except the computer

So the question is, could a bad computer cause this?

I need to drive it 2 hours away on Saturday morning and it isn't looking good so far.

Hope you guys can give me some advice

Thanks, Evan

 

[broncnaz]

Well not sure but EFI may draw a little power even when not running also things like stereos with a memory will also take power so the small spark can be normal I'd unhook the stereo and see if it sparks again. but a short could be backfeeding the computer and cuasing it it run bad or the computer could be fried might want to see if you can pull any codes.

 

[suckerpunched]

yes a small spark could be normal. check to see if its charging, ecm needs a certain amount of voltage to run, like 9 or so, below that it shuts down. At that point the battery is pretty much dead.

 

[77broncodriver]

Oh yeah, I ran the codes while off and on and only got the smog ones, I'll unhook the stereo and see if that's it, but it says it's charging at 14 when it's on, should I just go for a new computer?

 

[broncnaz]

I'd run down the wiring system first sometimes stray voltage just messes with the computer. could also just be that the computer didnt boot up correctly. Kinda like a home computer sometimes does.

 

[77broncodriver]

I went to go home tonight and it didnt start, just kept cranking and nothing, didnt feel like trying to figure it out so just left it. I dont know whats wrong with this thing, everything with the engine was working pretty good, well it always started till i just redid the hub and added an electric fan

 

[ransil]

Its never the computer !!!!!

start by checking your charging system
then check to see if your electrical system has a draw on it.

Need a better description of "no start" does it crank? does it crank lazy?

 

[Jerseydevil]

Can't he check for a draw by pulling fuses one at a time and checking for voltage across the fuse terminals? What should he expect to see on each with the key in the off position? Sounds like a few circuits should have a little current flowing, but most shouldn't; right?

 

[77broncodriver]

ransil the now start it that it just cranks and doesnt even try to start. and also my radio beeps when i turn the power off on the car and after a few seconds of cranking my radio beeps.. so it seems like its turning off power after a few seconds of cranking or something if that makes any sense.

so check to see if the ports where the fuses go when the key is off? see if things that arent suppose to have power are getting power?

 

[patterdale]

Pull the negative cable and conect a volt meter or test light fron the neg terminal to the cable. Remove fuses of things you know are drawing current like your stereo and anything that needs to have current to maintain memory. If you still have a draw pull fuses one at a time until the draw goes away and you should find your problem. A "short" will more often than not cause major smoke and then an "open" along with a need to rewire a bunch of stuff. The engine should run crappy at worst if the computer is bad but it should run. You most likely have a bad ignition part causing the no spark/run condition. I don't know what you mean by Hub so can't speak to that. You could have done something when you wired the fan so trace that down and make sure it is not hooked to the ignition wires.

 

[ssray]

Is the radio one with a removable faceplate? I have a Sony in a vehicle I recently bought that beeps after the ignition is turned off as a reminder to remove it. Maybe that's all that's going on with it as the start position removes power from a lot of circuits on older vehicles, radio included.

ransil the now start it that it just cranks and doesnt even try to start. and also my radio beeps when i turn the power off on the car and after a few seconds of cranking my radio beeps.. so it seems like its turning off power after a few seconds of cranking or something if that makes any sense.

so check to see if the ports where the fuses go when the key is off? see if things that arent suppose to have power are getting power?

 

[77broncodriver]

well just wrote out a long thing and it got deleted, long story short it started then died this morning. realized we spliced for the fan on the coil wire so fixed that and thats how it started.

the coils getting 14.5 while running and 10.5 while cranking but if i put the tester on the pos of coil and neg of coil it was only at 1.5 while cranking, not sure if thats supose to be like that.

also the tach,windshield wipers,radio went out and it was the wash,radio fuse, not sure why the tach was connected to that and that has something to do with the coil, so that seems weird.

while it was running and i drove it home it didnt seem really smooth when it was in the higher rpm, like 3-4k when it down shifted.

Im going to get a new coil and see what that does.

and patterdale, do you mean unhook the neg on the battery and put neg of tester on the neg post and pos on the tester on the neg wire? not sure if im following there

 

[patterdale]

Unhook the neg cable from the battery hook the voltmeter or test light across what you just unhooked. If you have it backwards the meter will just come up with a negative sign in front of the voltage reading. You followed what I said very well. It sounds like you pretty well have it fixed. Good work!!!

 

[77broncodriver]

i did that and it reads 12.5 with everything in and everything out. is that right?

I saw some messed up looking wires under the dash and fixed those and it seemed to help, it started up but still runs rough.

also turns out my transfercase seal went out and the tcase is filled with transmission oil.

its going to have to sit out this first month of school till i can come back to fix the rest

Evan

 

[blamejane]

Good luck in school Evan. Remember to come back to this thread and give us an update when you can.

 

[77broncodriver]

Will do, I'll be back for labor day to try too finish it up and bring it back with me, we will see how it goes

Thanks, Evan

 

[77broncodriver]

Just an update, I fixed some bad wires and it starts now but haven't been able to drive it, wrong seals, finally ordered the right one.

My brother needed the garage so the bronco got kicked to outside.. I'll be back home in a couple weeks and try to get it done finally.

It still doesn't run really smooth after everything, I want to get a new ecu but those things are expensive if it's not going to make a difference