Ferrari 328 expert advice needed

If it's a US version 328, first confirm/deny if the frequency valve is buzzing when the engine is running (it should).

 

In addition to Steve's suggestion take a close look at the inside and outside of the spark plug extenders. You are looking for pin sized burn marks. If you find any, replace the extender.

 

Better to touch the frequency valve to see if it is buzzing, but if it isn't, do a search on "protection relay" for prior threads.

 

I had this same issue on my 328. One time it was the extenders and after replacement it ran great. The next time it was the protection relay which after replacement I have not had an issue.

I also had a stumble after cold start up which was resolved with a costly Auxillary Air Valve (AAV) replacement.

I think, as Steve has noted, it is likely your protection relay which I found at Pelican Parts but I just searched their website and found it to be NLA. I did find it here for $78.29.

92861512402. Relay. 928-615-124-00, 92861512400.

Relay OEM part number 92861512400

Relay Cross reference part # 92861512402

Good luck.

 

I agree that it would be best if you had touched the frequency valve before (when things were working well) to calibrate yourself on how it should feel when buzzing, but I can't really say it more clearly than "touch the frequency valve with a finger to feel if it is buzzing" (it mechanically vibrates when operating).

PS Even if your frequency valve isn't buzzing, don't buy a protection relay yet. 99% of the time a dead frequency valve is caused by a bad protection relay, but an alternator problem (which intentionally causes the 10A fuse on the protection relay to blow), a wiring problem, or a bad frequency valve can also cause a dead frequency valve situation.

 

This is a Bosch relay which-starting in 1986 production-has a replaceable red 10 amp plastic GM fuse on the top in a red plastic sheath and is easily identifiable...If blown, the freak valve will not buzz atoll...99% of the time, this is the cause of a "bad" protection relay diagnosis-what the "landslide diode"-nee Zener diode-is protecting in MOST cases than not, is an extremely expensive ECU for the ABS-almost always Bosch again...
In these cars, this is NOT an issue until 1989, but nearly ALL Bosch systems had cookie cutter wiring harness design tress, and these were a functional over voltage surge protection for the L-jet ECU only, which incidentally, were the ONLY cars in the world which still used such an antiquated technology(coarse thread injectors, WUR, K-Jet) as late as 1989...

On RARE occasions, the diode which THIS fuse is protecting inside the box, is actually blown, and requires that the whole relay be bought-test, don't guess..
the wiring schematic is 100% of the time printed on these things, if you can't read this, you are already in over your head and can do far more damage than you realize...
THUS, proceed with caution...

The fuse typically blows from a "jump start" that has poor voltage control...It IS true, on very RARE occasions, your harness will be damaged, but people are far too prone to examine the most exotic possible cause when in truth, typically Occam's Razor is the REAL answer

 

Check spark plug wires for continuity. I recently checked mine and two were dead. Replaced all of the wires. Cars passed smog with flying colors where last time I smogged it, it barely passed.

 

To me the most likely thing is the protection relay - either its wiggled out of its connection or the fuse is blown / cracked.

if not that - then also check the connection to the "ecu" and that its clean and tight adn the rubber cover is on it as well. They are located in the passengers side of the trunk - un do the 4 bolts and remove the plate - the ecu and realy are attached to the underside ...

 

My fuse was fine, relay was bad. If you were closer I would let you swap out mine for confirmation. Do you know of any other 328 owners close by?

 

I am highly optimistic the new relay will resolve your issue.

 

Not to get too far off subject here, Steve, but I have wanted to tell you this for I don't know how many years now;

Your avatar always makes me think of a Zebra in my peripheral vision.

 

+1

 

Sounds like it is running on six cylinders?
Does it constantly sound that way or occasionally?
The first thing I would check is to make sure both banks are getting spark. These cars with a flat crankshaft and the dual ignition systems can run pretty well with one bank not firing. Sometimes those plugs on top of the ignition coils don't make good connections. I would test by grabbing each coil wire with an inductive timing light to verify a bank is not intermittently cutting-out. The primary wires can by fiddled with and you might find where the problem is..

 

+1, i thought i am the only one seeing this since no one mentioned it yet

 

I thought it was a zebra. Isn't it?

 

I guess that you can show a horse a picture, but you can't control what they think they see