over-run problem

[Rob fulham4eva]

since ive had my 2nd gt the car has always over-run after turning it off but just for a second now after the car sat for 4 days i had to jump start it (been having problems with the battery it i dnt start it up everyday) took it for a run parked on my drive turned the ignition off and the car was over-running so i had to stall it to stop it doing it
any ideas???? .

when i start the car recently it wants to rev at 1900 revs on start up(usually 1500 revs) and smells like its overfuelling on boost, once its warmed up its at a steady 800 revs

 

[ALaN]

Sounds like a vacuum leak to me mate.

 

[Rob fulham4eva]

Sounds like a vacuum leak to me mate.

cheers ill have a look at it tomorrow

 

[Starlet_Sam]

Lets get this straight, your car keeps running once the ignition is turned off? If so then a vacuum leak woul dnot be the cause.

 

[Rob fulham4eva]

Lets get this straight, your car keeps running once the ignition is turned off? If so then a vacuum leak woul dnot be the cause.

what would it be then????

 

[ALaN]

Well I'm only speaking from experience but hey you know best bud

 

[scot-ish]

i wouldnt think a Vac leak would cause that. maybe take part in the overfueling, but not the car still running. I'd imagine that being electrical, ignition related.

if you let it be, how long will it run for?
do you have a turbo timer?
what has been changed just before this started happening?

 

[J25GTi]

Vac leaks will keep it running, if you disconnect the vac line on the inlet mani it will run indefinitely!

 

[scot-ish]

i stand corrected,

in my understanding, you turn the ignition off, it will cut the fuel pump. without that, the car wont sit and continue to run.

 

[Rob fulham4eva]

all ive been doing is cv joints, there is a turbo timer on the car but it doesnt seem to work, its on the list lol

 

[scot-ish]

if its just on a harness, it might be worth removing, see how you get on there,

in the meantime, have a check for some vac leaks, as im unsure of it causing the problem listed, but others above have experienced it before.

 

[TheStarletGT]

i know what it is, you got a hidden turbo timer device that your not aware of.

 

[Rob fulham4eva]

if its just on a harness, it might be worth removing, see how you get on there,

in the meantime, have a check for some vac leaks, as im unsure of it causing the problem listed, but others above have experienced it before.

will do m8, im supposed to be modding this week not repairing ,typical aint it

 

[Texx]

Vac leaks will keep it running, if you disconnect the vac line on the inlet mani it will run indefinitely!

That's not going to happen. Once the ignition has been turned off the ECU is powered down which kills both the IGT signal to the ignition igniter and also the ground to the fuel pump relay.

i know what it is, you got a hidden turbo timer device that your not aware of.

That's most likely what's allowing the engine to run after the ignition switch is turned off. Have a check around the ignition switch connector on the steering column to see if there is anything plugged in.

when i start the car recently it wants to rev at 1900 revs on start up(usually 1500 revs) and smells like its overfuelling on boost, once its warmed up its at a steady 800 revs

If the fast idle only occurs when the engine is started from cold then I'd say that's normal.

 

[J25GTi]

see texx, I had the inlet mani vac pipe off and turned it on and it idled at 2.5k.

Then I turned it off and it carried on running (turned the timer off too)

And to stop it I had to pull the king lead out (hurt like hell too)

 

[Texx]

That seems quite odd. For the engine to run it needs fuel to burn and something to ignite the fuel. There's a possibility of the fuel igniting without a spark but that would indicate a serious problem, but there would still need to be a fuel supply. After the fuel pump has shut down there would still be enough pressure in the fuel rail to allow fuel injection for a few seconds, but the fuel injectors would need to be operating for the fuel to get into the engine. If the ECU has powered down the fuel injectors would not be operating.

 

[Sheldon]

see texx, I had the inlet mani vac pipe off and turned it on and it idled at 2.5k.

Then I turned it off and it carried on running (turned the timer off too)

And to stop it I had to pull the king lead out (hurt like hell too)

i dont know how ,many times i remeved the dump valve or intercooler pipe to work opn something and forget to put the vac line of the dump valve.. as soon as i swithc the engine on i notice the very high idle and swithc it off as i remember.. it will switch of immidiatly.

if you switched of your car and spark + fuel kept coming... thene id guess there was a turbo timer or ignition barrle didnt cut out the current

 

[Rob fulham4eva]

well the longer over-run is sorted dont know how but the battery seemed to be the problem. ive still got the slight over-run but cars in the garage waiting different repairs looks like bearings are shagged etc, so need that done before i look at over-run

 

[Starlet_Sam]

Well I'm only speaking from experience but hey you know best bud

Diesel by any chance? They can do it if the stop solenoid fails or it starts to consume its own oil. Not happening on a pertrol car with no live feeds to anything. It would indicate some sort of wiring fault, not a vacuum leak.