Battery died so jump started, now car won't idle... PLEASE HELP!

[MicK51]

i left my parkers on all day and the car wouldn't even turn over when i came back to it after work. We tried clutch starting it but there was just no spark so we waited for the jumper cables to arrive. Jump started it from the pics in the manual (it was all in japanese ) car started all right but blew HEAPS of smoke for a bit, idled ok then but as soon as i got going the smoke went away and so did the idle!

car won't even try and idle, just dies straight away. The engine warning light flashes at me whilst i'm driving but i can't see any pattern to it

other than that it revs fine, anyone got any suggestions?

[hippy]

maybe the battery is farked ... i've done this to my car a few times ... the computer gets reset ... only difference is that i connected the jumpers directly to the battery at the back ...

also maybe the computer is farked??

run some diagnotics

[Dragon18]

by jump starting your car etc i herd they you can give huge spikes through the car blowing fuses killing or damaging computer stero amp etc

so if you have an ecu in your car most do dont jump start it =)

[NuGGeT]

yeh i heard u cant jump start cars now days cause the ecu gets screwed up

[MicK51]

nah, u can jump start the r32... it tells u how to do it in the manual. just put + to + and - to earth (in the rb20det case earth is the engine)

[FIL]

you can jump start anything with the right gear....

i prefer to do it with a battery thats not connected to a car... (seeing as i sell em for a living, i usually have one lying around :-) )

cables with inbuilt surge protectors help also.... tho i beleive the major risk is actually to the donor car rather than the one being jumped....

what may have happened is that the ECU has reset... not sure if the 'line ECU's have this issue, but i have swapped batteries in a few daewoo's (the delco controlled ones (ie. camira engine)) and seen them refuse to idle until you run the car at about 3000 rpm for a couple of minutes, and the ECU remembers how to idle...

[hippy]

i've jumped started my car ... i got an r33gtst ... with previous model camry ... computer got reset but there was nothing else wrong ... i wouldn't jump start it with older cars though ...

[Mark]

Originally posted by hippy

i've jumped started my car ... i got an r33gtst ... with previous model camry ... computer got reset but there was nothing else wrong ... i wouldn't jump start it with older cars though ...

What difference does the age of the jumpER have to do with the jumpEE?

[blind_elk]

You will probably need a new battery (how old is the current 1?).

If you kill the battery, then jump start the car, the ECU detects that you are throwing lots of amps at the battery (to recharge it). This is an error condition that cause the ECU to totally mess with all the fueling / ignition parameters.

Often, stopping and re-starting the engine can make the condition go away, but in the longrun, the only solution is a new battery.

[hippy]

voltage spikes apparently .. or something like this .. this is what i've been told

[Guest FlyGuy]

Voltage spikes or maybe even amp spikes as you call them, isn't this why cars have fuses? Don't fuses stop damage, to say the ECU is not working just because you jump standard a car doesn't make a lot of sense to me...

My car got a flat battery once, and when its flat the car doesn't idle at all. If the battery is stuffed, get a new one...

[FIL]

fuses don't blow immediately.... they heat up when the current passing through them increases past their rated range... when they heat up enough, they melt....

ecu's are a particularly sensitive bit of electronics.... so i guess they could go before a fuse...

"My car got a flat battery once, and when its flat the car doesn't idle at all. If the battery is stuffed, get a new one..."

Well said... call the RAC... i get bored of working on commodores and corolla's all day.... :-)

[hippy]

yeah good explanation fil .. i work with micro controllers all day long so im pretty sure its a logical thing that could easily happen .. if the current or voltage goes over the allowed tolerance then sometimes the chips inside the computer ... seems that nissans like to use st micro brand of micro controller ... depending on wha the fuses are rated at and the kind of chips that the computer uses ... then its something which is quite possible to happen ...

[peter-flint]

Loosing all electrical power will cause the E.C.U. to reset to basic settings. It will slowly "learn" the settings as you drive it, did it myself when changing to Shell Optimax. Should be O.K. after a cruise around town.

[51jay]

Car is fine now Rule no 1......any probs with idle or rough running....check for vacuum leak first, then sludged up idle control or throttle sensor. Corrected both....no more problem