355 Cam phase sensor malfunction

Maybe while you are waiting for the new pins/sockets, you can look at other sensors and things? The manual is actually quite interesting. e.g. I didn't know that during start, because timing hasn't been fully established, the ECU squirts fuel into all cylinders simultaneously. No surprise then, that you get unburnt fuel being sent down the exhaust pipe during start.

Sorry, I've forgotten, when did the problem start? Were you idling? Accelerating? You said that you could get the engine to idle if you blipped the throttle periodically. What happens if you keep your foot on the throttle permanently (a little) from start, ignoring for the time being the fact that doing this will put your idle out of whack?

 

Since the problem is getting worse and the car is not running long enough to pick up faults, I was just wondering if a poorly regulating Idle Air Regulator might be contributing to the no start problem.Does the Idle Air Regulator buzz with the ignition in ON?

Yes, I know the 5.2 car only has 1 regulator feeding both sides, but... this problem is weird

I see the regulator gets power from the green wire (pin 5) on that plug you're working on. The green wire also powers the cam phase sensor, the MAF and the cat thermocouple ECUs. I think you checked the power on this before, but there may be some kind of intermittent problem there.

(EDIT: the green wire gets power from the injector control relay "M" in the passenger footwell. Maybe you could try reseating/percussing that?)

 

This might be a useful diagnostic tip in the future. If you can hear your 5.2 idle air regulator buzzing with the key in ON/RUN prior to start, it's a good sign that your injectors have power (as well as the cam phase sensor, MAF and cat thermocouple ECUs). The fuel pump is also (partly) controlled by the power from relay "M".

 

1+ month and 17 pages later...lets just replace all the parts already. Its the summer driving season!

 

These cars don't generally run rough when the loose a bank. They loose power, have slow response, idle speed drops, but being a flat crank, they run smooth like any other 4 cylinder would.

Running rough would be more symptomatic of intermittent misfires on one several different cylinders. The problem is that there has been conflicting info posted. First it was a cam sensor error, then bank 1 no spark with a scope trace that seemed to verify. Then a complete no start. Now bank 1 has spark and two odd cylinders on bank 2 are out, but still a no start. As for being flooded, you pulled the plugs. Were they wet? How about no fuel?

Yes, but remember 1/2 of the post were about whether the plugs are grounded, if it matters, and whether a closed current path is needed to create a spark. Physics 101 say no. The difference being "create" as opposed to "sustain".

But no, not replace parts, replace car.

 

$2000+ -worth of new parts... 17 pages of faultfinding. Grant will go nuts if the problem was only a dodgy relay, water in the fuel or something equally mundane.

Not sure who you're trying to convince there, John We all have our fixed opinions... and whether it's an earthing strap or, perhaps, a bonding strap which is keeping the engine in running order is yet to be proven (Reciprocating masses have a tendency to build up static electricity which may interfere with electronic components).

 

Not trying to convince anyone. Opinions are like ____(fill in the blank)____, everybody has one. I don't disagree with Miro that no ground is necessary to complete the current loop in a wasted spark ignition. That wasn't the point of that argument. The point was simple. The plugs are grounded.

The other issue was whether a closed loop is necessary to have a spark. It is not. That is a physical fact, not an opinion. A spark will form between two isolated, charged bodies if the potential difference between them is high enough. Said another way, take two sufficiently charged, isolated bodies and as you bring them close together a spark will occur between them. I presented an example of a magneto discharging to a cam shaft with no connection between them. There are plenty of other everyday example.

If you think about the wasted spark ignition in a 355, do you really believe both plugs initiate a spark at the exact same time? One plug must fire first. It may be a microsecond or even a nanosecond before the other, but the gap in one plug breaks down first without a completed loop. Only after the second plug gap breaks down is the loop completed. Sure, from a macroscopic view this doesn't make a difference for a 355 ignition, but it is what happens. There are numerous reason why one fires first. One of the most obvious is that the composition, temperature and pressure are different in the paired cylinders which translates to different dielectric break down.

Of course, none of this relates to Grant's problem, but it's fun.

 

Sorry to pick on Grant but how many pages until Grant's car makes stink? I say 20 pages. I will keep adding useless posts until we get there.

 

Maybe its time for a tech. Not such a bad suggestion.

 

One factor that needs to be considered in all of this is the human factor. When I was working in the dealership and I or someone else was stumped, the natural reaction was to go to your fellow tech and pick their brain. The only difference here is we are not there with Grant to actually do hands-on help. Of all of the hard to diagnose electrical problems that I can remember, the common denominator with all of them was a missed step in the flow chart. It is human nature to skip ahead and look into other systems before properly finishing the diagnosis with the first. For example, the tech says "I checked the ground AT the ECM and its good." BUT how was it checked? He says with a test light to power. After doing a voltage drop across the ground for the ECM its found to be questionable. Then the truth comes out. The whole reason the ground was never physically checked at the source with a DVOM was because it was located in a really hard to reach area down at the bell housing. After struggling to get the bolt out (that was double nutted) and cleaned up, the car starts. The tech just shakes his head out of frustration, because why did the test light light up? Well, because the ECM is not a test light, instead its a bunch of transistors and resistors etc, and a "Good" ground is one that has been tested for a voltage drop with a DVOM. Thats it. We are all human and will constantly keep chasing our tails on things like this. Sometimes I will just walk away from it for a day or two, and come back and start fresh forgetting about the previous diagnosis. It works more often than not.

 

Great points!

This exact issue came up with our very own Stooge Ernie's 348. Engine make stink with air spark and fuel. I was at his house and blew in some starter fluid. The car fired right up. I instantly proclaimed a fuel problem. To my surprise the ground strap to the motor was poor. It was test light "there" but poor. Like magic establishing a good ground fixed it. The starter fluid just made up for a weak spark.

 

I hear you about the ground. But, recall that Grant did look at the trigger signal for the coil on a scope and it showed that the trigger was indeed being grounded. Since it is grounded through the ECU I think there is a very good chance this isn't a grounding problem. But a couple of probes with a VM wouldn't hurt.

There is just too much going on here for internet diagnosis. Maybe Grant got a load of bad gas? Who knows. At this point I'd want the car in my garage before I offered further insight. But yes, I'd go back and start over. I would want to see the scope signal for all 4 triggers, cam and crank sensor, injector pulses. If that showed noting I'd probably look at fuel pressure and compression. It's still fuel, compression, spark, and it should run.

Just another reason I prefer the 95. Much easier to diagnose a problem when each bank runs independently.

 

True! about the only good thing with Ferrari 2 ecu cars but then we must have that dumb poorly engineered prone to failure SDECU system in case people are not bright enough to realize they are running on 1 bank.

 

I don't know about Leonardo but generally you can not check the crank sensor, other than for continuity, unless the car is running. A bad crank sensor would cause a no start. Check the impedance between the two crank sensor terminates at the ECU. It should be around 1k ohm +/- .

 

TJI ? or is that a late night typo?

What if the crank sensor has really weak coupling with the crank and is sending pulses at a random rate/strength that is only triggering ignition periodically. Was your tacho erratic or did your F1 warning light come on during your drive? Can you interrogate your F1 TCU with your Leonardo to see if there are any stored messages related to rpms?

 

My local Ferrari tech had some diagnostic sheets that he was using when trying to figure out what was wrong with my new engine harness last year. I assumed he got online access to them with his annual subscription to the SD1 tool. I'll see if I can dig them up. Basically, they showed typical values (resistance, volts, etc) of the engine harness components.Unfortunaely, some are with the engine running.

I don't know if this is a good thing. With a cold engine, the car may be operating in open loop mode, so, as your notes above say, the O2 sensor value will be given a value of "1" in that TJ equation. All the other values will be derived from the same sensors (MAF, crank, voltage, throttle position and coolant temperature).

 

Were you relying on the Galileo for ECU volts, Grant, or testing at ECU pin 26? I can't believe you were losing half a volt with a few extra feet of wiring. The cigarette lighter uses a different plug and fuse in the footwell relay panel. If you're running out of options, maybe you could check plug "I" on the fuse panel for loose pins and check the fuse holder pins. Unfortunately, that involves pulling more of your car to pieces.

Anyway, simple stuff first... Battery.