Punto (Mk1) What needs to be done?

[bluestripped]

Hello to all thanks for the inclusion. My query is one that a Fiat Dealer has yet to properly diagnose but having solved a static problem with the destruction of my remote central locking recently, all while I have spent £1500 on making my s reg someway to being a decent drive. I am left with now having the front shocks and springs replaced to finish the project but one niggling thing remains and that is the motor is hunting at times, fine at low revs but hold the revs at either idle or at 2K rpm and there is some loss of revs not by much only 250 to 500 rpm? and then back! I have had the HT leads replaced , spark plugs and throttle body cleaned and still this slight misfire continues. I try and solve it by releasing the fuel cap and from the resulting vacuum loss in the fuel tank there is some improvement at low revs. No hesitation of the motor at low revs results. Should I replace the fuel Pump???? or better still what should be replaced at 63K on a mark 1 Fiat punto 1.2 Sporting?I do also from time to time have a millisecond where all power is lost on the engine which as you can imaging in disconcerting to drive anywhere although not had any reliability problems, apart from the remote central locking. Looking out for your reply and valued comments on keeping my darling car tip top/

 

[fingers99]

Most likely cause is an air leak somewhere in the inlet manifold. (The hunting, that is.)

Try using a length of windscreen washer hose as a stethescope, see if you can find a hiss.

 

[blu73]

what needs doing at 63k kinda depends on what has been done previously, do you have history with the car? If not I'd lean towards doing everything.

everything being:
cambelt & tensioner
water pump
aux belt
oil & filter
air filter
coolant flush and refill
plugs & leads
check brake discs, pads, drums, shoes, rear wheel cylinders and tyres (replace as required)
renew brake fluid

thats all that springs to mind immediately. Then from there you are good for many thousands of miles, just annual fluid and filter changes.

 

[bluestripped]

Thanks for your replies, the hunting was solved in part by a new fuel Pump and not running the car from full to empty without releasing the fuel cap to let the vacuum out of the fuel system. Going well now, just left with lamda sensor and coil to replace at 64k NOW.

 

[fingers99]

You shouldn't have to do that!

I'd begin to suspect that the fuel filter needs changing (or that some twerp has put it on back to front).

 

[bluestripped]

Thanks for that I shall not as suggested. I am now on 67K done 3K since posting without to much hesitation. There is just this flat spot at 2K rpm when kept constant the revs drop by 200 and back up again. Will check the fuel filter thanks.