Problem starting car

[M0T]

My sister has a 1996 1.6l fiat punto which has been sat on the drive for 8 weeks collecting dust whilst she was away at uni.

Today she came home and tried to start it, the battery was practically dead so I hooked up a spare battery originally from a rover coupe (using jump leads) and tried that, but it wouldn't turn over.

I figured that the spare battery was dead so I took the one that is currently in my rover coupe (1.8) out and connected that up and used jump leads, the starter struggled and turned it over once. Now the battery from the coupe is an oversized one (oversized for the coupe, designed for starting 2 litre diesels), significantly larger in terms of output than the one in the fiat, and fully charged.

I thought I was doing it wrong (not being an expert in jumping cars) so I put the battery back in the rover and started that and waited for a bit then tried to jump the fiat. It seemed to have slightly more power but still struggled to turn the engine over and wouldn't start.

Now I connected the 2 positive terminals together and connected the negative from the starter car to the engine block as I thought it should be done and have achieved nothing. Prior to this the car worked fine.

Can anyone else suggest what else could be causing this problem, as it behaves as if it does not have enough juice.

 

[Mickey_D]

Ok, there's several different schools of thought on how to do this properly, but this is the way I've been taught by trial and error (read: this is how I do it after doing it wrong several times and it costing me LOTS of money before finally getting it right).

1. (in your case) Make sure that the Rover is shut off. Completely. Key out of ignition. Make sure cars are not touching.

2. Connect Red cable to both (+) terminals. Connect one end of black cable to (-) post on the Rover. Connect other end of black wire to a handy bare metal surface on the Fiat (alternator bracket is generally a good one).

3. Start Rover.

4. Go have a smoke (in other words, let the Rover run for about 10-25 minutes to give it time to charge the battery in the Fiat).

5. Shut off Rover (not a necessity if it's an older car with a carb).

6. Start Fiat.

7. If it doesn't want to turn over well, redo steps 3-6.

If it still won't start after two or three attempts, the battery in the Fiat is toast. Get a new one. Car batteries do NOT like being flat dead, especially for any extended period of time. The battery sulfates and will no longer hold a charge (or allow one through).

 

[lozza23_uk]

you really need the engine running in *** rover, your not taking *** battery OUT of the rover are you?

as soon as you start a car, the alternator pumps the power back in to the battery. hence bringing the power up.

however it does sound as if you are having an earthing issue. does it generate a nice healthy spark (not weedy and small) when you connect the black cable to the engine block (a lifting ring should do it)

if it doesnt. something is wrong with the conection. and no matter how big the battery is, it wont pass on any current to the fiat.

 

[silversurfer]

I swapped over batteries between cars that were not related and apart from not starting the car, it stopped a lot of the electrics ever working again. I always thought it must be a fuse that had gone but I couldnt see any blown.

The car was due to be scrapped anyway so it was not so bad but I never figured out why really especially when Im told its not a problem to do this normally.

Just realised you used jump leads, probably wise.


Try charging up the battery outside of the car, check all the fluid levels

 

[Mickey_D]

you really need the engine running in the rover.

On older carb cars, this is true. But in a lot of newer cars, the sudden drain of an additional battery being connected or the sudden impact of the full draw of another car trying to start can send a voltage spike through the ignition computer (ECU) and other sensitive electronic components (SATNAV, high end ICE, etc).

It's a fairly mild risk of it happening, but it's not one I like to take a chance on.

There's a 99% chance that nothing evil will happen if you leave the car running, but I certainly wouldn't want to have the guilt of someone coming back and saying thier good car got fried because of advice I gave......