xXWhiteXjJeepXx

Hows it goin guys my names Devin im using a buddy of mines account for now but ive been lurking on here for a couple years.. Anyways lemme get to the point here. last night i was up on the mountain by my house with a couple buddies of mine some of which i didnt really know. one of them had left their AC on accidentily and needed a jump. i went ahead and jumped it for him so he could go home but the ******* who put the jumper cables on(mutual friend) ended up putting them on backwords without me noticing so i started my jeep up and revved it up a bit to give the other car some juice and the cables started smoking and actually caught on fire. the jeep immediately died. long story short that ended with me ripping the cables off my battery and burning the crap out of my hand.

This is where it gets interesting.. I called another buddy of mine who had jumper cables to come up and try and get my jeep started since my battery had been completely drained from the reverse current going through it. he came up and after about 5 mins of him idling and revving his truck up i barely got my jeep to start. Right after this it was running just like it normally does(good) but the check engine light came on which i assume was from low voltage.

I ended up driving it back down the mountain without any problems except for dimming lights and my radio would flicker on and off. and a jumpy speedometer. once i got back onto residential streets it completely died at the stop sign and couldnt get it to crank or anything. ended up leaving it over night to come back in the morning, got it towed home, bought new battery and now it cranks but will not run and is not getting spark. i assume it isnt getting fuel because the fuel pump wont prime when i turn the key now and i couldnt smell any fumes while trying to start it.

What im really trying to figure out now is if my computer got fried do to the reverse current flowing through all of my electical? or if there is some sort of limp mode these jeeps can go in to prevent it from starting?

The jeep is a 1994 SE with 140,000 miles and was rebuilt around 100,000. its got a brand new 02 sensor and spark plugs. checked fuses and none that i could find were blown. No melted wires or anything unusual that i could find.

if anyone has ever had a similiar problem or know an idiot who has crossed jumper cables on a vehicle and had it not run anymore please feel free to give any advice or possible solutions u may have. sorry for the rant haha but this is my daily driver and i need it for work ASAP. Very healthy running jeep before this happened and i really dont know where to start with wut i should replace. i really dont want to go buy a new computer for it if thats not even the problem. Thanks

timberwolf

it could have fried any number of things
see if you can read any error codes from the comp

start small with a new fuel pump relay
you could also bypass the relay to see if the pump stills gets power
hit the junkyard for a cheap ignition coil to try
have the alternator tested

xXWhiteXjJeepXx

a buddy of mine has a scanner that he can let me use hopefully later tonight or tomorrow so hopefully i can pinpoint wut it is with that and ill go ahead and post up the codes if it throws any.

i was definately thinking the distributor was a concern for the non spark issue so thanks for the advice ill have to try that. and how exactly do u bypass a relay?

xXWhiteXjJeepXx

oh and would it even turn over with a faulty alternator? the alternator was actually my first thought because i have a taurus fan that seemed to really drain the alternators power and could have possibly put too much wear and tear on it?? the strange part with that is though i actually got the jeep to run after this incident it was just when i tried to start it today with the new battery it didnt even want to fire at all

timberwolf

the dimming lights and radio while driving makes it seems like the alternator wasn't charging

it should be able to start without an alternator and run without a battery

to bypass the relay, take it out and use a short jumper wire to make the connection between the 30 pin and 87 pin in the relay socket. see if you hear the pump run

ColoradoCorey

Well, if it was me I would go alternator first. Because you more than likely fried your alternator that is a good thing. There are diodes in the alternator that dont allow current to travel back the opposite direction.

Im not gonna say you DIDNT fry anything else but I would definatley go Alt first.

xXWhiteXjJeepXx

UPDATE: just had my buddy come over with his scanner and it said it could not read the computer. He tells me its only done this once on a car which actually ended up having a fried computer. im not gonna just leave it at that though and call it a day ill definately look into the alternator for sure

meanwhile while were doing this i decided to turn the ignition on and try and start it and the fuel pump turned on this time and i actually started her for a good 5 seconds before she died on me again.. this was only after having the battery disconnected for a few hours. smelled really rich and was able to do this twice and the second time having it cut out within 2 or 3 seconds. Does it sound more computer related to u guys now seeing as how the fuel pump would come back on after resetting the computer?

DFlintstone

A possible scenario. It stopped charging, then you made it until the juice ran out, then it died. As far as the pump running...Idk how mine does it , but sometimes if it's pressured up the pump will not come on with the key every time. (definitely dodgy ground there, mine IS diffeent, and that's when it had just been on)

I might leave it disconnected, overnight. (won't hurt), and make double sure the fuses are OK, defiantly including mini fuses. Then see what she does with a good charged battery. It might be "picky" about voltage. you want to see 12.7..14 running. (being lower might be why it dies). If the blinkers are slow and the lights are dim, and the belt is tight I might have the ALT tested.

Just my.02!

You should have a ceramic ballast resistor there near the air cleaner. Bat voltage goes to the front, and a little less goes out the rear straight to the fuel pump. That resistor is not mandatory, mostly just makes the pump a little quieter. You might check/bypass that..see if that helps.

The "Key Tricks"
Older (OBDI) models - Start with the ignition off. Within five seconds, switch the key on, off, on, off, on. ("On" is NOT "Start" and "Off" is NOT "Lock"). The "check engine" light will flash. Count the flashes. Each code is a two digit code, so a (for example) 23 would be FLASH FLASH (pause) FLASH FLASH FLASH (long pause). It will never flash more than 9 times, so watch for those pauses!

rrich

You said it runs, or did. That means the PCM is not dead.

Try disconnecting the alternator to eliminate that as a problem.

In the power distribution box, look for a blown fusable link - I think the '94's have them. Otherwise look near the fuse box inside for the fusable link and where the power goes through the firewall to the fuse block.

And look very closely at the power cables inside the distribution box.

Inspect/clean the ground connection - where the (-) batt cable attaches to the engine and the one by the dipstick.

The super big current draw caused a connection to burn, now it's resistive. Sometimes the heavy load from a starter breaks through the resistance, but the lower current from everything else doesn't.

freegdr

check for power in pdc there are fuseable links that could come into play also,gotta confirm currents getting where it should .

xXWhiteXjJeepXx

thanks for the advice guys im definately going to take a close look at all the things mentioned above and let u know wut i find.

And flinstone i tried the ignition on off thing and i couldnt get the check engine light to come on and flash a code

DFlintstone

Yea, I don't see much on that actually working well for anybody...maybe it works so good, they just are not here!

Btw, I have a 90, (A different Renix system), and I haven't noticed any "smart guys" suggesting it, but at some point in the last 10 years, having some sort of issue, I jumped bat. power right to that rear terminal on the (a fore mentioned) ballast resistor wire, powering the pump and the Jeep ran.
Since that "back feeds" to the same circuit that has power with the key on, I did that with the key on.

That might be of "diagnostic value". In your case I'm not sure how worried you need to be about hooking up something wrong, at this point.

rrich

I don't know if it's the same or similar - I had a massive power failure in my CHEV ASTRO VAN - couldn't find the fusable links anywhere. Cranks, but nothing else.

Finally after chasing the wiring I found them - the backside of the fuse block where a connector is on the engine side of the firewall had the fusable links inside it! Found it by tracing the smaller wire from the + batt post to the connector. FSM does not show it, it just says there are 4 of them.
A test light probing/stabbing into the wire found power went in but didn't come out.

Fusable links are where you find them - not always in consistent or logical places.

xXWhiteXjJeepXx

ok so far ive replaced all of my battery cables and it starts and primes the fuel pump every time. it runs now but on 5 cylinders.. cylinder #6 isnt getting spark for some reason but its being filled with gas.. i also checked my cap and rotor and tested my spark plug wires and cleaned the spark plugs which were barely a month old anyways. inspected all fuses and fuseable links and couldnt find anything melted or burned or anything like that. im gonna try and blow all of the gas out of that cylinder and start it up and if the same thing keeps happening im at a loss. At this point i think ill just take it to a shop

tiwvr1

Get alt tested, if it test good the computer is most likely bad. The dimming lights and such when it was running means it wasent charging. The pcm controls the alt. on these. So... if the alt test, good, most likely the comp is bad, and causing all your problems. Swap one out from one of your buddys jeeps and see if it runs.