88 Mondial 3.2 sudden power loss

Does it get real quiet and smooth when it loses power? It sounds electrical
I think you may be intermittanly losing a coil pack - check the connections at both coils.

Something else to check is the relay fuse in the back trunk on the K-jet board.

I understand how you feel about being spooked to drive it (must be a pilot thing) - this is why I converted to a reliable single distributor and never looked back.

Let us know!

 

I would also bet it's electrical, but if that doesn't check out, it could be fuel delivery. Clogged fuel line or filter. Happened to me once and the car would come and go until I changed the line.

One other thing that's not likely at all but also happened to me was a clog past the charcoal cannister in the emissions vacuum line and I was getting a vacuum in the fuel tanks. It started right after I filled them up with gas. Same symptoms: ran crappy, low power, would come and go.

Ken

 

Fuse box. Ignition rotor. RPM sensor. I'd check in that order.

 

It appears you've gone through the ignition....but this sounds identical to the symptoms I experienced when I had an ignition module go bad.

Is it isolated to one bank of cylinders? Any indication of the "slow down" light?

I also zip-tied the fuses on the ECU in the trunk as I've been told they tend to work themselves loose.

 

If you are saying that you confirmed good spark on all cylinders during the bad running condition (i.e., you confirmed that it's not ignition related), another electrical thing to check is that you still have +12V power to run the "with Lambda" part of your K-Jet with Lambda system -- did you check/feel if the Frequency (Lambda) Valve was buzzing (+12V power present), or not buzzing (no +12V power), during the bad running condition? (This is related to Russ' suggestion about checking "the relay fuse in the back trunk on the K-jet board" -- but checks more than just the fuse).

 

What, coil packs being pricy? We're talking about ignition coils, right, one per bank, high voltage output, etc.? I replaced them in '02 on my old 308 for reasonable cost.

 

Can't say I follow that explanation (you checked the rear bank twice?), and realize it's tough when the problem is intermittent. In any case, if the bad running recurs, put a hand on the frequency valve to check (something you can do on the road without any tools).

Please also comment on Russ' question -- during the bad running was it running:

A. smoothly, but weakly, or

B. rough and needed some throttle to stay running?

 

Right, and also whether or not the "Slow Down" (aka Catalytic Converter overhearting) light came on - and if not, can you verify that it works at all (should come on briefly during startup).

 

I switched coil pacs on Rachel, with a friend's pac off his 348. Voila!!! Got a used replacement board (pac) from T. Rutlands and all is well. When those things "go", they seem "come & go" for quite a while.

Cheers, Hank

 

Here's a link to the thread when I had my problems with the ignition module...very helpful for me during the diagnosis.

The module on top of the coil is a very common reason for problems with a bank intermittent firing and isn't very expensive...<$100.00

Hope the thread helps...

http://www.ferrarichat.com/forum/showthread.php?t=118860&highlight=wolftalk

 

No trouble -- thought that you may have misspoke.

For "running smoothly", you're chasing the right likely suspect -- ignition (since your injection architecture doesn't really have a failure mode that can take out just one bank. But put a finger or two on the frequency valve to calibrate yourself -- it's something that you can do in a tux on a date in an emergency ).

 

check the connectors to the ignition modules, under the car on the lower lower left I think. I have seen bad connections there, will kill one bank . Mike

 

it is next to the fuel distributor that looks like an electric fuel injector (because that is what it is) and as a cable plugged into it.

 

See Fig 57 on page 66 in your 481/87 OM (frequency valve = Lambda valve = metering valve). The frequency valve is driven by a PWM (rectangular wave) electrical signal from the injection ECU, and it acts in series with the fuel distributor to add or subtract fuel. When cold, the PWM signal is set to a fixed (default) duty cycle (which adds a fixed amount of fuel) and the system runs like a "dumb" K-Jet. When warm, the injection ECU looks at the signal coming from the O2 sensor and slightly changes the duty cycle of the PWM signal going to the the frequency valve (which slightly changes the amount of fuel being delivered) to try to keep the O2 sensor output at 0.5V (average).

The PWM signal (a current rapidly switching "on" and "off") causes the frequency valve to vibrate/buzz (whether cold or warm) -- consequently, a "dead" (non-vibrating) frequency valve is a clear sign of a problem (whether cold or warm) on a K-Jet with Lambda system like yours.
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You will need to replace the entire relay if something is bouncing around inside - that happened to me as well. It is probably the fairly common O2 protection relay. Take it to a Bosch place or use the number on the relay to replace it. When you replace this relay, all should be well.

It is always possible that you had two things going on.

Let us know.

 

Loose bits are never a good sign , but, if you want to be absolutely sure, the way the protection relay should work is (when the engine is running):

terminal 30 should be at +12V
terminal 15 should be at +12V
terminal 31 should be ground

when these conditions are met, the contact points inside the protection relay "close" and terminal 87 is connected to terminal 30 -- so terminal 87 is at +12V also (and this is the +12V power that goes to run the injection ECU which subsequently runs the frequency valve).

If you confirm the three conditions above are met, but terminal 87 is not at +12V, you can be sure the protection relay needs replacement.

99% likely that the protection relay itself is bad (with your report of loose bits and a dead frequency valve), but I just wanted to let you know how to be sure before buying.