355 F355 Stuttering

Yep, even tried starting the engine. The lights on the device are active as soon as its connected to the power, so I'm pretty sure it should be connecting. I'll try it on another car though...

 

Just plugged it into our Skoda Octavia and it worked like a charm. My mobile immediately found it as a Bluetooth device, paired, and then used an app to connect to the car. One clear difference is that in the Octavia the red power light was on, but the blue Bluetooth light was off. On the Ferrari the blue light flashes.

The 3-pin adapter cable seems to connect well, but have I bought the wrong type of diagnostic plug? I got an OBDII, should I have gotten something that was just OBD to support older cars?

 

Popping out to collect a hard-wired OBDII scanner to see if that's any better...

 

Even a wired OBDII scanner doesn't work . It lights up to show it's got power, but the device never initialises. There's nothing obviously "broken" on the wires from the ECU to the 3-pin plug.

 

Unplugging the "Fiat 3-pin adapter wire" from the 3-pin ECU cable gives exactly the same results! So, neither diagnostic tool is able to "see" the ECU to communicate with it. Seems unlikely that it's the adapter wire as it's new. Do 3-pin ECU cables fail?

 

Check the specs on the reader it might not work on OBD 1
What make and model are you using


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Ah, does it need to be OBD 1, not 2?

The Bluetooth tool is a Vgate iCar Pro BLE 4.0 (Vgate iCar Pro BLE 4.0 OBD2 Diagnostic Tool Fault Code Reader OBDII Compatible Car Adapter Check Engine Light for iOS, Android and Windows : Amazon.co.uk: Automotive), the wired tool is a Streetwize OBDII reader (https://www.argos.co.uk/product/6876166).

 

1996 is a change over year in USA not sure about anywhere else so depending on the car it can be one or the other I asking because most OBD2 readers will not read OBD and if that what you have can be why it works on your other car and not the Ferrari


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On my car, if I don’t get the power up sequence right, the scanner doesn’t work. Have you tried powering up the Motronic ECU and adaptor first before turning on the scanner?

What car brand are you selecting on the scanner. Some have Ferrari, but really aren’t suitable. Audi or BMW may work.

I’ve never heard of OBD1 in relation to the 5.2 before. Anyway, maybe someone from the UK can recommend a scanner brand.

How are you powering the OBD2 adaptor? What are you using as an earth?

 

Hiya. I'll try a few different power up orders, nice idea. Regarding which car brand to choose on the scanner, I never get to that option. The bluetooth one won't pair, and the wired one never gets to its boot screen. I'm powering the adapter by connecting the 2 wires that came with the 3-pin adapter to wires that I stripped from an old TomTom charger. It has the red and black cables for live and earth. Not sure how much that you can make out from the attached?
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I tried powering the ECU (ignition to on + immobilizer off), then powering the 3-pin adapter, then connecting the scanner. Same result, I'm afraid.

 

Should work. It looks like the unit has power. Did you check the voltage on the red and black leads?

What brand is your hardwire (non-USB) scanner?

 

Streetwize https://www.argos.co.uk/product/6876166

 

According to the reviews, one in 10 people reported that it didn't work on their car.

Not really sure if it's the adaptor or the scanners causing the problem.

This thread says that voltage is critical for bluetooth scanners:

https://www.ferrarichat.com/forum/threads/f355-scan-tool-non-obdii.525775/

 

Interestingly, the voltage is only 5V from my jerry-rigged power adapter. Presumably because that was what TomTom needed? So, I'm thinking that that cigarette plug adapter just isn't supplying enough power?
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Cigarette lighters put out 12 volts (i.e. battery voltage). Your TomTom adaptor may have a built in transformer to change the voltage to 5 volts.

Sounds like you've found your problem.

If your local electronics store doesn't have an adaptor, there seems to be plenty online:

https://www.ebay.co.uk/itm/303725677730?

(although the lead on that one isn't the longest... and they all seem to come from China... so you'll have a long wait)

 

Yep, that was it! I removed the plug and clipped the wires from the 3-pin cable directly into the socket - et voila, it works .

Now, both my apps report zero engine fault codes. Kinda expected that as I've not had the Check Engine light on. Next step, I think, will be to start the engine and then monitor things like cylinders, MAF, and O2 sensors. Any other suggestions for what data to look at?
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cc @Qavion OK, we have data ... but I'm gonna need some help interpreting it please. Car was at idle for about 4-5 minutes whilst I cycled through all the measurable things on the app and took screenshots. Car stalled the first time I fired it up (after about 2-3 seconds) - it hasn't done that before.

Summary Data

• MAF - 15.4 g/s at start, dropping to 12.2 g/s after a few minutes
• Bank 1 Sensor 1 0.58v
• Bank 1 Sensor 2 0.49v
• Bank 2 Sensor 1 0.48v
• Bank 2 Sensor 2 0.49v
• Long term fuel % trim Bank 1 8.6%
• Long term fuel % trim Bank 2 3.1%
  
• Timing advance 9 (average, but fluctuates from 8 to 10)

Observations and Questions

• There was no Short Term fuel data available for either bank. Is this because the sensors bust, or it just hadn't got warm enough to engage it yet?
• What is a normal MAF value for an F355 at idle?
• Are Sensor 1s pre-cat, and Sensor 2s post-cat?
• Bank 1 Sensor 1 is higher than all the others. I assume this suggests that the fuel is too rich?
• Why are there 4 O2 sensors, not 8? Does B1S1 measure cylinders 1 AND 2?
• LTFT on bank 1 is WAY higher than bank 2 - or vice versa. What's a normal reading?
• Should Timing Advance been constant? What's normal for an F355?

O2 Sensor

The values in the summary were measured fairly quickly after ignition. However, after a few minutes some of them really started bouncing around. The below summary is of the sensors "bouncing" a bit later on.

• Bank 1 Sensor 1 0.53v (very bouncy)
• Bank 1 Sensor 2 0.89v (stable)
• Bank 2 Sensor 1 0.78v (bouncy)
• Bank 2 Sensor 2 0.49v

I'll separate the images in the following posts to make is more obvious.

 

Readings taken very quickly after ignition...


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Readings taken after 3-5 minutes...

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Other screenshots (can't remember the timings of them!)...

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You have very rudimentary questions. I suggest you find a youtube tutorial on the subject of O2 sensors and read up on that. By the way, good job on getting the OBD2 to work.

Your car has 2 banks L/R. Each bank has one sensor (sensor 1) to aid in fuel injection, and one sensor (sensor 2) to monitor the efficiency of the cat converter (2 for the car).
The warm up period of a few minutes after cold start, the engine runs open loop and does not monitor O2 sensors (and that is why those values are stable). After warming up, the engine ECU uses the O2 sensor signal to control its ignition and fuel trims, that is why the sensor 1 signals SHOULD bounce around.

On your car, since both banks do not behave in the same way (one is bouncy the other is VERY bouncy), it points to an ignition to a vacuum problem on that bank, which also leads to a Slow Down Light problem. If I have to guess, it is probably bank 1 since the LTFT is 8%, adding to that the STFT number and it indicates a problem somewhere.

The question is ... where.

If you have a smoke machine, now is the time to use it. Also same if you have a laser thermometer. Find which cat converter is running hotter than the other. Find which cylinder is running hotter than the other.

At least, you are on the way to data-informed diagnosis, and not merely guessing.

 

Thanks - glad the diagnostic tool is finally working!

Not sure how to measure which cylinder is running hotter. I assume I need to get the laser gun onto the exhaust ports, but they're pretty inaccessible.

 

I seem to have some fluid on the exhaust manifold for cylinder 1. Can't quite reach it to tell what it is, but it looks oily.
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Your perseverance is admirable; kudos and hats off. Happy to hear that you got the scanner to provide info.

Smoke testing is your next pursuit. it will help laser in on your issues. Pretty sure you have one or more leaks.