Technical Gt Punto 95

[KCrean76]

Well I've retimed the car with no change. She's revving up and down most of the time. I've changed the idle speed control valve ,maf sensor ,lambda sensor, any suggestions kids I'm going to do a compression test during the week just to check but it only does it when it warms up I'm lost ?

 

[bugsymike]

Well I've retimed the car with no change. She's revving up and down most of the time. I've changed the idle speed control valve ,maf sensor ,lambda sensor, any suggestions kids I'm going to do a compression test during the week just to check but it only does it when it warms up I'm lost ?

I am guessing an air/vacuum leak somewhere that is often a cause of engine revs fluctuating, check all the vacuum pipes, and manifold for leaks, plus the brake servo can leak air also.
A trick that may help to locate an air leak is a length of rubber hose to your ear and the other end move around checking different areas to pinpoint.
Unlikely to be compression if only once warmed up, more likely to be air leak as when cold the cars fuel system will make it run rich which hides the issue.
A quick check on the servo is to pull the pipe off and block it with your finger, I have located several over the years like that. Though can still be the pipe to the servo also.

 

[KCrean76]

I am guessing an air/vacuum leak somewhere that is often a cause of engine revs fluctuating, check all the vacuum pipes, and manifold for leaks, plus the brake servo can leak air also.
A trick that may help to locate an air leak is a length of rubber hose to your ear and the other end move around checking different areas to pinpoint.
Unlikely to be compression if only once warmed up, more likely to be air leak as when cold the cars fuel system will make it run rich which hides the issue.
A quick check on the servo is to pull the pipe off and block it with your finger, I have located several over the years like that. Though can still be the pipe to the servo also.

Thanks Mike I'll try that.

 

[blu73]

spraying little bit of brake cleaner or similar around suspect joints etc is good for finding leaks, revs will rise if theres a leak where you spray it..

looks like your engine management light is on sometimes, have you pulled the fault codes? Theres a how to in the guides section if you not done it before

 

[blu73]

oh, and welcome to FF didnt notice how new you were before

 

[KCrean76]

spraying little bit of brake cleaner or similar around suspect joints etc is good for finding leaks, revs will rise if theres a leak where you spray it..

looks like your engine management light is on sometimes, have you pulled the fault codes? Theres a how to in the guides section if you not done it before

Ya it came on as I was unplugging different things on the engine ti see if it made a difference to the way the car was idling. I should have unplugged the battery but drove on. I'm going to use brake cleaner around the joints to see what happens