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Cylinder 1 Misfire on 2010 California

Discussion in 'Technical Q&A' started by Minnesota, Jun 8, 2020.

  1. Minnesota

    Minnesota Rookie
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    Mar 17, 2020
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    Aaron Harkins
    I recently acquired a 2010 California in an auction that has around 30k miles. It has a recurring misfire on cylinder 1 when under load and at around 5-6k RPM. It seems to run great otherwise, but if I accelerate hard I can sometimes feel a slight hesitation with an audible sputter in the higher RPM range just before the CEL comes on with an engine control system error message. It throws a P0301 code. It seems to accelerate just fine until it hits that RPM range. The problem is recurring, but it only happens about half of the time under those conditions. Some drives are perfectly fine, but when it starts to misfire it will usually continue to misfire consistently under those conditions thereafter.

    I don't have any service records for the vehicle. The oil was dirty when I bought it and it had the wrong oil filter installed. (I think it may have had a filter for a 360 installed?) I reset the service indicator after changing the oil, oil filter, air filters and transmission fluid. The service indicator was last reset in 2018, so it may have been a couple of years.

    One other things to note is that the engine oil has a slight fuel smell to it. My understanding that that oil dilution can be an issue with GDI engines, especially if there are misfires, but I have not smelled enough oil to know what is uncommon. Maybe that is just a symptom of the misfiring and not indicative of another problem, but I am not sure at this point.

    Changing the plugs and coils had no improvement. I pulled the injectors and had them tested and cleaned. Some of the injectors were very restricted and/or leaking, but all are good following cleaning. However, cleaning the injectors did not resolve the issue.

    I have not performed a compression or leak down test yet. I need to find a better 10mm adapter for my compression tester that will actually fit into the sockets. Also, is there procedure for disabling the injection and ignition while doing a compression test for these cars? Do I need to pull some fuses or relays unless I have access to a DEIS tester? I do not think I could do that with my Launch x431 pro. (I can manually actuate each of the injectors using it, which is how I dropped the pressure in the fuel rails before removal.)

    The Launch provides some access to the various systems and live data on the California, but I am not an expert on modern engines and need to do some more research on what might be out of spec regarding the available data such as ignition advance, etc.

    When I had the intake manifold off to replace the injectors, I noticed that the intake ports in the engine seemed pretty dirty. They looked like they had a good coating of oily sludge. I probably should have taken the time to clean them out before reinstalling the intake manifold, but at that point I assumed the problem was one of the severely restricted injectors that had been operating at less than 50% capacity. If one of the intake valves is fouled, could that cause a misfire only at high RPM?

    I have also been suspecting that there could be an issue with one of the variable timing solenoids for bank 1. I have read that the VVT kicks on to adjust the timing when under load at higher RPMs, which would be consistent with when I experience the misfiring.

    If a VVT solenoid is malfunctioning, could that cause a recurring misfire code for a single cylinder without additional DTC codes? The code is always for a misfire on cylinder 1. I would think that a VVT issue would affect all of the cylinders in that bank, but I assume the ECU takes over with the malfunction is detected.

    I noticed there is probably a slight oil leak somewhere around those solenoids on the right bank, which is where the problem is. No oil is visibly leaking or dripping, but the tops of the solenoids, the gasket around them and the valve cover at and below the gasket is dirty which seems to indicate a slight leak. I am not experiencing any rattling upon start up, so hopefully the variators on the cams are still okay.

    My understanding is that the VVT solenoids used in the F136 engines sometimes fail from high pressure oil leaching up into the coil and connectors. The dielectric grease around the electrical connectors is brown and gummy. The workshop manual says to try applying UNIFLOR 8917 grease to the connectors before replacing the control solenoids. (That particular grease is available online for the reasonable price of $600 for a 14g jar.) Any reason why I couldn't use some other kind of high-temp dielectric grease used for spark plugs? I assume there are issues with the electrical connectors?

    I am going to try to testing the actuation of the VVT solenoids using a 12v battery, test for shorts and see if there is any difference between them in coil resistance. That might confirm a likely problem, but it might not rule out a mechanical failure in the solenoid valves.

    Has anyone had a similar problem? Anything I should look for in live data streams that could be useful? Anything related to timing or fuel trims that could be helpful?
     
  2. vjd3

    vjd3 Formula 3
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    Jun 3, 2005
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    Vic
    Hey Aaron ... this is pretty technical in nature ... I'd suggest reposting it in the Technical Q&A forum, as there are some Ferrari techs who respond there and they might not frequent this forum.
     
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  3. Minnesota

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    Mar 17, 2020
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    Aaron Harkins
    Thank you for the tip. I think I know what the issue is now, but I will repost in the technical forum this weekend if my latest suspicions are incorrect. A temperature check on each catalytic converter showed a decrease of 100-120 degrees from front to back (the temp should increase by around 20 degrees since the catalytic reaction creates heat), which tells me that neither is working and both are likely obstructed. The bank one cat is worse, but both are bad. I am going to do a pressure check this weekend to confirm after a back pressure gauge arrives.

    An obstructed cat would explain why the misfiring is only under load at high RPM, since that is when exhaust volume is highest. It is probably just coincidental that the ECU adjusts engine timing at the same time. Four of the injectors were dripping before cleaning, which means fuel was probably leaking from the rails into cylinders after shutdown. That fuel was probably dumped into the cats upon starting which destroyed them. Fingers crossed!
     
  4. AlfistaPortoghese

    AlfistaPortoghese Moderator
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    Mar 18, 2014
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    Nuno
    Moved to Technical Q&A.

    Kind regards,

    Nuno.
     
  5. Minnesota

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    Mar 17, 2020
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    Aaron Harkins
    I was able to do some more diagnostics on the California today. The compression test was good, with each cylinder testing between 155 and 160 (and with the suspect cylinder 1 coming in at 160). I also did a leak down test on cylinders 1 and 8, and both were fine.

    Both catalytic converters are shot but fortunate are not plugged. They do not heat up at all, so I doubt they are working. But back pressure before each converter was below .5 psi at 2,500 rpm. We don’t have emissions testing here in Minnesota, but I will get around to replacing them eventually. (Do you really have to remove the subframe to replace the damn catalytic converters, which would require supporting the engine with a hoist and straps, etc.? Ferrari designs things to be easy and efficient.)

    Since I have now likely ruled out plugs, coils, injectors and compression as the cause of the recurring misfire, I think the problem could either be the dirty intake ports obstructing air flow into the cylinders or potentially the VVT solenoids. I used a can of CRC GDI valve cleaner this morning and let it sit for an hour. Then I did a spirited test drive for a couple of hours and only had one misfire. Lots of acceleration that would usually have triggered a misfire. I think the issue is getting better, but I am not sure if that is due to the valve cleaner, finally having clean oil or just driving it hard.

    Anyways, I have not had any trouble codes for the catalytic converters or the O2 sensors, but my launch shows that “Catalyst Protection Active Fuel Cutoff Bank 1” is active 100% of the time. Catalyst protection for Bank 2 frequently switches on and off but is usually off. What that that mean? I couldn’t find much about how the Bosch ECMs actually works in that regard. Is the ECM leaning out the fuel on bank 1 to protect the catalytic converter (which I already know doesn’t function anyways)?

    Something else I noticed is that the “Condition for Lambda Closed Loop” for both upstream and downstream catalyst bank 2 is always “Open Loop”. Downstream catalyst bank 1 is “Open Loop” about 99% of the time. For upstream bank 1, it is “Closed Loop” about 90% of the time. Any thoughts about how to interpret those readings? (I am more familiar with carburetors than lambda sensors.)

    I am planning to install a couple of the miniature inline catalytic converters for downstream O2 sensors. They are a bargain at $12. They will trick the sensors and ECM into believing there are functioning cats on the vehicle. Not sure if that will make a difference.



    Sent from my iPhone using FerrariChat.com mobile app
     
  6. Minnesota

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    Mar 17, 2020
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    Aaron Harkins
    I thought I would provide an update on my progress. I now suspect a faulty high pressure fuel pump (HPFP) on bank 1. There is significant oil dilution after only 250 miles since it was changed. The oil smells like fuel and the level increased by about a quart. I do not think that could be solely from blow by related to the misfires (which only occur under load at high RPM). The injectors were recently cleaned and tested, so I do not believe they are leaking. Compression seems fine as well. The fuel trims seem fine except during the misfires.

    I looked back at the the live data that I recorded of the misfires for diagnostic purposes and noticed that when the misfires occur, the bank 1 rail pressure is always significantly below the setpoint pressure determined by the ECM. For example, the rail pressure was only 108 bar while the ECU was requesting 172 bar during the last misfire event. The disparity only seems to happen at high RPM, and the HPFP seems to keep up okay at lower engine speeds.

    I have not heard of this happening before, but I suspect fuel is leaking out of the HPFP and into the engine, at least at high pressure. That could explain both the significant oil dilution and the misfires. There are no trouble codes for anything except for the misfires. But the only way fuel could get into the engine is through either the pump or the cylinders. Has anyone ever had oil dilution from a faulty HPFP?

    I just ordered a new pump, and I will need to take the intake manifold off again to disconnect the pipe to the fuel rail. I will probably go ahead and walnut blast the intakes while the manifold is off, since they looked pretty dirty.
     
  7. Minnesota

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    Mar 17, 2020
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    Aaron Harkins
    I wanted to post an update to confirm that the cause was a bad high-pressure fuel pump. Everything is working 100% with a new pump installed.
     
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