Technical 1997 Punto 1.1 Sx - Can jump starting damage the ECU ?

[d1ckyboy]

Following on from this thread i posted regarding Starting problems on my 1997 1.1 Punto.

https://www.fiatforum.com/punto/283...ng-after-plug-coil-lead-change.html?p=2877057

I was wandering if it is possible i have damaged my ECU by jump starting it too much whilst trying to get to the route of the cause.

Reason i ask is i received a reply saying this

As you stated you said the timing seems fine. i would be inclined to check that again. you will prob find it a tooth out either way as these engines will still run but causes problems such as hard to start and wont rev above 2000 rpm. has it ever had a rocker cover gasket fitted ? as iv seen it many times before a bit of old hard black sealer falls down the cambelt area and then causes the belt to jump a tooth and cause all the syptems you have said. The easy way of checking you timing is buy a new cambelt GENUINE and they have two yellow marks which will line up the bottom pulley which should be at 10 o clock and then another mark on the top pulley which will be about 9 o clock. Also remove the rubber cover from the gearbox which is on the top and there be a mark on the fly wheel which lines up on the last triangle mark on the gearbox. then you know its all timed up and all ok.

Also i would avoid jump starting these cars as the engine e.c.u s do not like the spike of voltage. i would just charge the battery off the car.

I just wandered if it is possible.

Opinions welcome

 

[fingers99]

I think it's sloppy thinking. The only spike is from 0 - 12v, just as would occur if starting the car normally. The Mk1/SPI ECUs are remarkably tough as ECUs go..

 

[d1ckyboy]

I think it's sloppy thinking. The only spike is from 0 - 12v, just as would occur if starting the car normally. The Mk1/SPI ECUs are remarkably tough as ECUs go..

I thought it was a load of ball0cks !!

 

[DaveMcT]

There will be voltage spikes well above 12V from any starter. Its irrelevant about the battery jump start or normal start.

However, the ECU can be damaged if both spark plugs on one coil (1 + 4 or 2 + 3) are disconnected as the back emf from the coil cant go via the remaining spark plug so kicks back to the ECU.

Its never advisable to run the donor car engine while starting a dead car as this can damage the donor alternator when it tries to supply the starter. There is also no need to rev the t*ts of the faulty car when it does eventually fire. Just keep it spinning around 1500 revs so it cant stall again.

 

[s and b]

trader i know had a big bill 10 years ago for spiking a mk1 punto when he was in a rush to do a deal
it might only be a mk1 but it still has a plate of silicon dips in the ecu ready to fry on a surge

if it is a mk2 punto or later then the following advice should be heeded

Procedure for Jump Starting a Vehicle fitted with BSI
Certain precautions must be observed when jump starting vehicles fitted with a BSI. Failure to do so can result in spiking
ECUs including the BSI and engine management. Remember, when connecting the leads always fit the earth lead
clamp last when completing the jump circuit and disconnect it first on removal.
1. Having connected the jump leads, start the donor vehicle, then start the vehicle with the flat battery.
2. Wait a few minutes for its tick-over to stabilise. Do not rev the engine.
3. Switch on its headlights, heated rear window and heater fan.
4. Remove the jump leads from the vehicles.
5. Switch off all loads one by one.
6. Allow vehicle to idle and recharge battery.
7.
This procedure prevents the alternator, suddenly loaded by the removal of the jump leads, from creating a high voltage
spike before the alternator's regulator can stabilise the voltage

 

[Brendan W]

the recommended procedure when refitting a battery to a V70 is to turn the key to pos 1 and switch on lights before reconnecting. This dampens down the voltage spikes and protects the ECU.