F355 power loss and bucking, losing my mind

Hi there,

I'm a pretty new member here. My name is Tim, and I work at a small British and Italian car shop in Minnesota.

We've had an F355 Spyder in and out of the shop for the same problem for a very long time, and this car has a long history that I'm not entirely sure of. However, it's my turn to deal with it, and I'm kind of at a loss. Being relatively new to Ferrari work, I figured I'd ask the kind and knowledgable folks on FerrariChat.

The car is a 1997 Ferrari F355 Spyder. The only mods it has that I know of, are gutted cats. Well, and the MIL is out/unplugged.

The only codes I'm getting are P1447, P1448, and P1691. Those should all be explained by the gutted cats, and the unplugged MIL.

Now, the problem I am having with the car is that it seems to have no power. It doesn't really like to rev under any load. Sitting there, it revs up nice, but as soon as you put it in gear and let the clutch out, it's just guttless. The second part of this, is that it has a harsh bucking up to about 3,000rpm. It also smells pretty rich at idle.

My idle is just above 1000rpm, and the MAF reads about 11g/s. The injectors all have about 16.5ohms of resistance.

Long-term fuel trim on both banks is about 25% and the short-term on bank 1 stays around 0, and around 5-10 on bank 2.

As far as I could tell, doing various testing, there are no vacuum leaks, but I'm open to checking common trouble spots more thoroughly.

Any info, thoughts, ideas, or input would be greatly appreciated. Thanks in advance.

Tim

 

Fantastic, I will pull the crank sensor now, and report back.

Thank you very much.

 

So, I clean up the crank sensor, and I still have the same thing. It was raining yesterday, so I had to wait until today to drive it.

I'm in the middle of a compression check right now. I had to stop and work on another urgent customer car. So far, all the compression number are 200+.

The downside of being an independent shop, working of newer Ferraris, is that we are allowed to own the Ferrari scan tools. I'm sure this would have been much easier to figure out if we did.

One thing I noticed yesterday, with the car running inside the shop, doors open, standing behind the car, is that it is very, very rich. Like, eye burning rich.

I think my next place to check is the FPRs.

The other funny thing about the way it runs, is at about 4500ish RPM, if you lay into the throttle easily, but swiftly, it acts like it's going to take off, and then just loses it's will to live.

Thanks for all the input so far. I will keep you all posted.

 

Figured it out and fixed it today. Thank god.

I tested fuel pressure and it was amazingly low, at only 30psi!!!! It's amazing the thing even ran at all.

So, ordered up a new pump. I dropped the old pump out, and it was obvious someone had been in there before. Well, whoever it was, didn't clip the hard plastic fuel feed line on all the way. Another bit of good news, is that it was very apparent that someone had replaced the fuel pump when they were in there, so I was able to return the pump I had just bought.

I cleaned everything up, put it all back together, and took it for a drive. Good as new.

Thanks for all the suggestions, guys.