Hi Guys, my neighbour's got a flat battery. I was just going over to help her but I seem to remember that using a Z to jump start risks frying my ECU.

 

Is this true or am I just being paranoid?

hi,

i think you are just been paranoid,

but remember connect to the flat battery first and then connect to your good battery,

also rev the zed to about 2000rpm(full output of alternater) for least 2-3mins before you try to start the other car,don't try straight away,let it get a bit of charge in the other battery

---hth---

--neil--

 

------------------

thanks neil - do I connect +ve to +ve first or -ve to -ve?

 

 

hi sorry man went out

you should connect the -ve to the car your jumping first t(not to battery of other car but a good earth point)then connect to yours,

then connect +ve to his car battery and then to your car battery ok run your engine for a short while at fast idle then after 3 mins say try and start car if it doesn't go straight away leave for 3 mins before you try again

--hth--

--neil--

 

------------------

hi

its not a vauxhall with fuel injection is it?

 

------------------

thanks, neil - no, it's a late model Golf which has been left standing for 2 weeks. Does it every time, apparently.....

no worries it's just that vauxhalls are sometimes right PITA to get started as the comp needs good 12+volts in order to start and if the bat is really flat it takes ages to start

 

--neil--

 

------------------

i also heard that you can blow your alternator or ecu if you connect or disconect while engine is running so switch off befor you do jag xjs`s are prone to it dont know about the z though

Better to not have your car running when trying to start other car,as i found out to my cost on a 24v cosworth,ECU went tits up!.

OK guys - still confused. (Don't worry about neighbour - she's sorted.) But still interested in case I ever need or need to give jump start to anyone.

 

Toger has heard that connect/disconnect while engine running can cause probs.

Tony had ECU blow while trying to start the other car.

 

Does this mean that I should connect up the batteries the way neil describes. Then run my engine for a few mins. Then stop. Then disconnect. Then try to start the other car?

 

 

[This message has been edited by Gio (edited 09-09-2002).]

a mate of mine said if you use one of these : http://www.drapertools.com/draper/templates/draper/products.asp?param=30&ig_id=5623&title=VOLTAGE+SURGE+PROTECTORS

 

you won't get any problems.........

 

Vijay

 

hi everyone,

can,t really see how you can blow the ecu from jump starting one car to another,

my reasoning on this as the alternator is voltage limited to 14.4v but seen some up to 15v on really flat batteries,and you are only taking current away not increasing it?

now starting a car with a battery booster(like what the AA use)can damage all your electrical systems as in order to get really high cranking amps the voltage on these can be as high as 20v which could possibly damage ecu's,etc

--neil--

 

------------------