Hi Guys, Here a question for you,I have recently changed the tensioner bearings/ belts and water pump on the 308. I have checked the carbs for air leaks and checked the firing order,but when I rev the engine the revs are very slow to return to idle. Any ideas much appreciated. Jazz
Look for the thread where Greg328 was having similar trouble with his warm idle setting........it should be around 900 - 1,000RPM.... Despite his LogIn he's dealing with a 1977 308GTB......
Put a timing light on it and check that both banks are returning to idle speed timing mark by 12-1500 rpm. If they hang up at a higher advance timing, it will make the motor slow to idle down. Also, make sure your not running to lean on the mix screws. On my car I was running at 2 1/4 turns out, and had cranked up the idle speed to compensate. Made it very erratic and slow to idle down. Once I opened up the mixture to 3 turns, I was able to idle it way way down, and now it falls off to idle speed rapido.
Yeah, possible air leak but sounds like you didn't mess with the carbs/linkage. Check to see if your valve timing is off (since you did do belts).
Many thanks for the responses,with regard to the timing marks according to the workshop manual I have,it alludes to the timing being set upwith the engine on the bench,is this so as I have been getting TDC by removing the plug and checking on No 1 cylinder,as I cannot see where you view the timing marks on the flywheel with the bell housing attached,unless of course you knowledgable chaps out there can tell me otherwise. Regards Jazz
Unless you are locating TDC very precisely by using a degree wheel with a piston stop, your attempts to locate it with a screwdriver in the cylinder, etc., can frustrate your efforts. The marks on the flywheel can be very difficult to see. Even harder if they were ground off to clean up the clutch surface or if it is dirty or greasy. You may want to spray brake parts cleaner in there when you think its close so as to clean up the marks? You will find them, or whats left of them, on the area of the flywheel between the starter teeth and the pressure plate. There is a very long dwell period where the piston hangs around TDC while the crank is turning, so you have to really be watching the flywheel and very slowly turn the motor once your device in the plug hole starts to indicate the piston is topping out. I think what you might be refering to about "on the bench" is referring to the distributors.
don't laugh....make sure the floor mat (if you have one) isn't pushing against the gas pedal. I took the car on a little trip once and couldn't figure out why the idle was high, I'd rev it and rev it and it just wouldn't come down, until I thought maybe the gas pedal was stuck and saw the mat pushed up against the pedal. One of those "DOH!" moments.
Hi Guys, Many thanks for your replys,My fellow Ferrari fiddler (Mark) will be taking up the baton as from tomorrow whilst I visit the old colonials down in New Zealand! I am hoping for a text in the three weeks I am away to say he has sorted it! I shall be passing on all your wise advice to him and he might just be coming back to the forum for some more advice. Going off on a tangent,I have just purchased a waterpump for the car, where oh where do Ferrari get their prices from? downright profiteering. What do you think? Best Regards Dave
