SDL and overheated cats/headers

I didn't say Tim was wrong about the wire. But it's not a smoking gun. It's a gun found in a ditch near the crime seen that needs to be checked out. I have suggested a simple test to verify. Take it or leave it. If it was my car I would certainly start by checking if the wire is transmitting spark. If not then I would have some confidence that it was the cause. In any case, I would certainly replace all the wire.

 

In my case the test you suggest was not valid. The plug exhibited strong spark with the wire out of the loom. Once compressed, with all the bends, pressure at the rubber gasket and compressed under the cam center cover the wire would fail.
In my case it was the smoking gun. If I understand the Ferrari diagnostic system, the SD2 would show the faulty wire.
Just my personal experience.

 

I just hope Kettle gets this straightened out. It's been what, over a year since he bought the car and even with the help of the Ferrari Chat brain trust he still haven't gotten it to pass CA emissions, as far as I know.

 

What you want is spiral wound wire. I would guess that the Mag-wire wound stuff is that but I would confirm it. But, and please do not be offended, based on the installation problems with your GCK I would recommend getting a pre-make wire set. Or at least see if you can have someone experienced with putting these together do it for you.

 

OEM wires are solid core.

 

Where is the resistance coming from Tim, the extenders?

I believe you are correct. I was think of the 308.

Still recommend Kettle have someone assemble them.

 

If the wire is an open circuit, it's a problem. Resistor spark plug wires typically should test about 1000 ohms per foot of length. The 355 wires are actually solid core with a resistor element at each end. They measure 5K to 7K ohms typically. If you get zero there is likely a problem where the ends are attached. I have also seen a coil-end connector that was "open". There really isn't any more you need to know about it. If you want to conduct an experiment to see how many gaps the voltage will jump go ahead but it doesn't fix the problem. Observing a spark plug in open air is a lot different than one in the head on a compression stroke. There is a lot more resistance to spark inside a running engine. As I previously stated, you won't necessarily get a misfire code from a single bad plug wire regardless what PDF you post. It's how it works in the real World.

Fix the wire (it's really simple to do) clean or (preferably) replace plugs. test drive the car briefly, measure the temperature of each Cat with an IR temperature gun. If it's fixed, both cats will be approximately the same temperature, 400 - 500F. If the affected side is a couple hundred degrees higher, then it's time to look at another variable .

 

Buy wound core. Solid core will misfire, if my experience is any indication. (Remember, tho, I'm a Bozo)

 

In defense of ketel and the braintrust, you John are part of it. There have been many suggestions by the trust to ketel including very strong suggestions from a few of us who have had hands on the ketelmobile. We know what the ketelmobile needs but the implementations of suggestions and ideas from those who have and have not laid hands on the car have been at ketel's pace and his tolerance and time for jumping in. He could just pay to have the car sorted too. But each enjoys the hobby in his own way. I give ketel a big high five for sticking it out and learning while exposing all his foibles right here on Fchat. Who has balls big enough to do that? The ketelmobile has good bones. He will get it sorted in his own time and one day he will be giving the advice to the next set of 355 newbies.

 

Tim, not trying to start a argument and, as I have said, I agree that a broken wire should be replaced. But I will stand by my statement that just because the wire is broken does not necessarily result in a miss fire. You don't have to agree. There is a very big difference between measured resistance with an ohm meter and the ability of a conductor to transmit a very high voltage pulse across a small break. Just as you may see arcs jumping from the wires through the insulation to ground, it's dielectric breakdown of what ever is in the gap. And I think you mean infinite resistance when the wire is broken. I guess we could argue the ability of OBD II to detect a misfile until the cows come home. There would be little point of having it if it didn't work since one of its primary purposes is to protect the cats in case the misfire results in raw fuel in the exhaust. If it doesn't work on a 355 that is another issue. It certainly works on other cars.

Anyway, the point is to help get Kettle's car finally running correctly. That seems to have eluded the FChat brain trust to date for one reason or another. If replacing the wire fixes the cat problem that would be great. If not, move on to the next step.

 

Puhleez, I'm not quoting theory, I have experienced this very problem on similar cars.

 

Maybe I can't read, or missed it. But what is this cars problem? What are we chasing? Are we chasing a misfire? Are we chasing as slowdown light (which could be triggered by a misfire).

Does the car have a constant miss at idle? Has a compression test and leak down been done? Are there holes in the manifolds?, clogged or broken cats? Clogged muffler due to broken cats?

Has a scan tool been plugged into this car ? What's the fuel trim doing? Airflow rates, coolant temps, injector pluse rate, has the car been smoke tested for vacuum leaks, etc etc.

 

What did Ferrari botched? Huh? I have a pretty darn nice, near original car that runs very well, Ferrari did not botch any of it and I did not and do not need to mess with all of the electrical connections.

 

I thought you did not want to rehash dirt on the 355? Do you really want to go there? And honestly at under 600 miles driven per year yeah even a yugo would be considered to "run well."

 

I don't appreciate bashing Ferrari for a problem they did not create. And, I did 3k my first 5 month season. Yeah, the car runs great and it's not botched.

Go design and build cars and show us and Ferrari how to do it since you have the keys to the castle.

 

Then who created the issues? Ford? The car has been a pickle since it was new.

 

I guess in your world Valve guides and headers are not an issue? This is a good thread Dave don't ruin it.

 

Valve guides and headers are not the topic of this thread. Again, it's easy to be critical of a design than be a designer.

 

Howie,

So the deal is Ketel is learning and learning at his pace. His 355 really needs an engine out and complete going through from injector service to connections evaluation. He needs to know what he is starting with but does not have the tools or the knowledge at this time. Some would just pay to play. He has chosen to learn, fighting small battles and this thread is just about one of them. It is his hobby and he is enjoying it. Its a big boy toy and while some would think it blasphemy to learn on a 355, guys bet $50k or $100k on a stock market bet every day. Ketel is getting way more out of his 355 than the guy with the perfect Ferrari that he only polishes. Ketel has driven 2000miles in his 355 just to come bar-be-que with some Stooges and he brings beer! We should be the ones buying him beers from making the drive. I say good for him!

 

We actually agree. I applaud him for his efforts and diligence.

 

Wow, sorry you're still having problems Ketel. Good luck.

 

Please let's stop this bashing. Many cars of the era had a host of problems. Some similar. Sticky switches, were common in several brands. Bad electronics, want to talk British? Porsche made engines that grenaded and a class action suite was filed against them and won. Here is an interesting quote,

This is from a Jan, 2013 GM service bulletin re the LS7 Corvette engine.

Even Mazda had problems with early Miata due to what is referred to as the short crank problem. XXX= GM

Kettle, good luck with getting you car sorted. You have a great deal of patients. It took me 3years to find the car I wanted. But if it had turned out the have the problems you are experiencing I would have sold it for scrap by now.