Mechanics

FERRARI 308 RPM PROBLEM

1984 Ferrari 308

Engine Performance problem
1984 Ferrari 308 V8 Two Wheel Drive Manual 41K miles

For an '84 Ferrari 308 QV with Bosch K-Jetronic CIS. The car starts easily and runs but when accelerated it takes a long time for the RPM to increase. Then it starts popping and misfiring. The brake pedal is very hard and requires extra effort indicating no assist or boost. I'm guessing a vacuum leak but don't know where to begin. Also, could either the warm up compensator or auxillary-air valve possibly be implicated?
Avatar
Vq803
December 8, 2008.



Lets start with the brakes as that may be all your problem. Now you need to find the brake booster and check the vacuum line going to it for any leaks or brakes in it if all looks good then unplug the vacuum line from the brake booster and make sure you have vacuum if so then plug the vacuum line off and check if the rpm's seem to increase like normal (do not drive it when doing this). If the rpm's seem to act like your use to then the brake booster is at fault and should be replaced.

Racefan966
Dec 8, 2008.
I disconnected the brake booster line and there was plenty of residual vacuum so it appears that a vacuum leak is not the problem. I started the car and let it run for 10 minutes after which time the sluggish throttle and popping disappeared. Could it be the warm-up compensator?

Tiny
Vq803
Dec 17, 2008.
I could be a temp sensor this tells the computer how cold the engine is so it know's when to use the cold start injector. If you have a digital multi meter then I may be able to find a test for this get back to me and we go from there.

Racefan966
Dec 18, 2008.