348 Hot Start Issue: I Have Tried Everything! | Page 4 | FerrariChat

348 Hot Start Issue: I Have Tried Everything!

Discussion in '348/355' started by POLO35, Feb 2, 2025.

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  1. m.stojanovic

    m.stojanovic F1 Rookie
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    Dec 22, 2011
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    Miroljub Stojanovic
    Although it does not seem to be a possible cause of your issue, disconnect the 6-pin connectors of the Exhaust ECUs and see if it makes any change, just to eliminate bank shutdown (perhaps you have already tried this?).
     
  2. POLO35

    POLO35 Formula Junior

    Feb 21, 2005
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    Appreciate the info. What happened with mine was I replaced only the hall sensor from the Volvo and screwed it to the original Bosch-Ferrari mounting plate and had to use tiny nuts and screws and the rotor ever, ever so slightly was nicking the nuts. That was the problem.
     
  3. yelcab

    yelcab F1 World Champ
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    That is the cause of the hot-start problem?
     
  4. fatbillybob

    fatbillybob Two Time F1 World Champ
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    so self-inflicted gunshot wound????
     
  5. Robbe

    Robbe Formula Junior
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    I am guessing not, why else would there be a need to replace the original sensor...
     
  6. POLO35

    POLO35 Formula Junior

    Feb 21, 2005
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    Well.... we will know today the new sensor is scheduled for delivery by 5:00 so I will post back ASAP. How I started messing with the sensor in the first place is while troubleshooting this hot start problem I noticed that the plug had completely disintegrated on the sensor end so I replaced it with the Volvo sensor. But if you look at my OEM sensor you can clearly see a crack in the resin on the back of it which makes me hopeful that it was bad in fact to begin with. I'm very doubtful that this is going to be the problem I don't know what else it could be but I'm just very doubtful
     
  7. fatbillybob

    fatbillybob Two Time F1 World Champ
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    I guess I'm confused? So you think you know the problem and order a part but you don't think that's the solution to the problem??????
     
  8. POLO35

    POLO35 Formula Junior

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    #83 POLO35, Feb 14, 2025
    Last edited: Feb 14, 2025
    Correct. I have literally literally replaced almost every single possible electrical component and sensor to no avail and for it to be the sensor I still have my doubts but I'm replacing it on principal and I'm replacing it because the original plug is disintegrated and I'm replacing it because the original sensor has a crack in the resin but I still feel that the problem May lie elsewhere like possibly the injectors themselves. But just to give some other discouraging examples I took a look at my original coils and the backside of them are cracked visibly cracked from age and Heat and I thought okay this is the problem I replaced them with brand new coils and no difference at all whatsoever. Another example I inspected the multi-pin wire harnesses for the injection underneath the manifold and the one side was corroded so badly with fuzzy green corrosion I thought oh my gosh this has to be the problem cleaned them up put it all back together no difference at all whatsoever.
    This is why I'm skeptical that this sensor is going to be the problem
     
  9. fatbillybob

    fatbillybob Two Time F1 World Champ
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    Where I was going with the severely smashing the pins to secure good contact speaks to your quote above. When these cars were new the electronics sucked! 35 years later the OEM wiring did not get better. Montezemolo called the 348 the worst ferrari ever produced. It was because of the wiring. We used to call it ghostbusting. We cleaned connectors and ghosts returned. We used magic stabilant 22 and ghosts returned. Finally, Helms came up with a lasting solution the gold connector pin replacement system. You don't have to use gold pins. You can use oem style tin pins. The TPS sensors use gold pins so you use gold pins there if you want. The green corrosion you saw did not end at the connector you cleaned. Cleaning isn't enough. If you depin that same connector and cut off the pin strip back 3/8" of wire and then wire brush that wire a dust cloud of corrosion will come off that wire! In order to have the beginning of good running and mixture control as ferrari intended you have to have a good wiring harness. It is a first basic that might not solve you problem but I bet it will if everything else is proper factory. If you remove your FI harness and open it up you will be shocked at the kindergarten wiring from Ferrari. Yup like a 6 y/0 did it. A simple rebuild of the FI harness with milspec wire from McMaster Carr is a minimum I do. A re-pin of the complete harness is easy but time consuming. It is easy to F-up too if you do not pay attention to detail. Re-pin of the ECU connector is critical too. It is a transformative process with the NLA Helms kit. I have done it on 3 Ferraris. My electronics has near Japanese -like reliability. We got the crazy out of the 348 decades ago. You are just the current owner walking the path we have already endured.

    Ferrari makes some cruddy stuff. Those bosch sensors the dissolve is a known problem. I bought the KIA sensor to replace the crank sensors. I bought a dozen decades ago they were so cheap and I sill have not gone through my stock they last so long compared to the OE ferrai that failed in short order. I have those same 348 kia sensors running my 550 maranello and it's been over 10 years on those same sensors.
     
  10. johnk...

    johnk... F1 World Champ
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    I've kind of browsed this thread. And by no means an expert. But what I read in the 1st post is: starts and runs fine cold; sarts and runs fine warm (what every warm is). Mostly fails to start hot unless given WOT. (But will start hot if shut off and immediately restarted.) To me this speaks of air/fuel ratio. One thing I would do is immediately upon a hot start attempt that fails is to shut it off and pull the plugs to see if they are wet before trying a WOT start. Nothing else to add.
     
  11. fatbillybob

    fatbillybob Two Time F1 World Champ
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    I asked him to spray starter fluid when hot and the car starts. Car would not start if plugs wet with fuel plus starter fluid as even more fuel. IIRC he also pulled plugs and found them dry as expected.
     
  12. POLO35

    POLO35 Formula Junior

    Feb 21, 2005
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    Well I got the sensor but I'm in the doghouse and can't put it in tonight hopefully tomorrow. But totally agree with Fat Billy these cars have horrible Electrics especially the multi-pin round connectors in the doors. When I bought the car pretty much nothing worked power locks power windows power mirrors...everything had to be repaired and resoldered it's just awful. Will report back tomorrow. And in response to Johnk things have changed a bit it now pretty much runs like crap all the time. Will start cold but other than that will not restart unless you put the pedal to the floor. And yes when it doesn't start the 1 through 4 cylinder plugs are soaking wet
     
  13. fatbillybob

    fatbillybob Two Time F1 World Champ
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    #88 fatbillybob, Feb 14, 2025
    Last edited: Feb 14, 2025

    Plugs wet is a different problem from electronics. You are all over the place with this car. You need to get back to basics. Base timing right? Spark? Fuel? If running both banks just one? not running side spark? not running side fuel? Throwing parts at it and randomly cleaning electrical connectors is not going to get you there.

    [QUOTE="POLO35, post: 149995643, member: 16810" I just got done pulling both sides of the injector rails putting empty water bottles under each injector and cranking over the engine fully expecting to see leakage and they are 100% let me repeat 100% tight not one single of the eight injectors leaked not one drop! [/QUOTE]

    You are not being consistent in your own thread. How do you have wet plugs on page 4 but not on page 2 posts? Sorry no put down intended but I question your ability to give good data so we can help.
     
  14. johnk...

    johnk... F1 World Champ
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    A couple of things. If the plugs were wet immediately after a hot no start then it isn;t excess fuel and it isn't no spark if it's getting fuel. If the plugs are dry then it isn;t getting fuel.

    1) Getting fuel, no spark = wet plugs.

    2) Plugs dry, no fuel - with or without spark.
    Have you checked spark on 1-4 when it doesn't start? I believe you said you replaced the coils but what about the power modules. Standard Bosch part. Bosch 0227 100 200 https://www.fcpeuro.com/products/porsche-ignition-control-module-911-bosch-0227100200
     
  15. POLO35

    POLO35 Formula Junior

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    I agree I'm all over the board with this troubleshooting.... but it seems like this car is developing new problems as I go... initially the plugs were dry as a bone before during and after the hot start symptoms now Banks 1-4 are soaking wet. I absolutely appreciate everyone sticking with this lame thread and throwing out advice I feel like I'm very very close to figuring this out. The only positive thing in checking all these connections and replacing sensors and plugs and filters uncovers new problem areas like for example the round corroded injector plug connector and the cam sensor disintegrated plug/cracked sensor. Will absolutely post hopefully tomorrow morning after installing the new cam sensor. And yes sir the car has brand new OEM Bosch coils and aftermarket ignition control modules which Mount right next to the coils. And just to clarify when the car does not start and the banks 1-4 are soaking wet there is in fact spark which I verified by physically pulling the wires and checking but the plugs are soaking wet which tells me it's a timing issue on banks one through four...... hopefully from a bad cam sensor
     
  16. Portofino

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    #91 Portofino, Feb 15, 2025
    Last edited: Feb 15, 2025
    1- Does it still [ after all the changes of new parts + disturbed connectors ] start from stone cold normally ?

    2- Assuming yes to Q 1 ^ …..does it run perfectly on that first start until you switch it off and attempt a “ hot start “ ?


    Where exactly are we NOW with symptoms ?

    It’s gotten worse if understood the last sentence s of the post above ^ .

    Timing out .
    Have you checked the cam pulley bolts thinking they ( at least one bank ) are loose enough slightly altering the timing enough but not enough to cause catastrophic interference?

    How long ago was the engine out for the belts + who did it ?

    If so ( others chime in Ps ) how easy is it to verify/ eliminate timing = thinking whip the valve cover off and get a spanner underneath on the crank pulley and use a stick to find TDC through a plug hole on cyl 1 and note the timing marks alignment on the cam shaft . I know it’s not degree ing as such but it would be nice to see both banks factory marks there or there about aligned .Or miles out to confirm a timing error .
     
  17. tbakowsky

    tbakowsky F1 World Champ
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    This sounds like a flywheel issue. Or you have one of then slow down ecu's giving you a problem.
     
  18. fatbillybob

    fatbillybob Two Time F1 World Champ
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    Could be! He said he did a repack of the flywheel but a bad one with worn plastic parts no amount of grease is going to fix that. What grease was used? what mass of grease was used? Can you still hear some rattle on shutdown? Can you hear rattle on engine cranking?
     
  19. POLO35

    POLO35 Formula Junior

    Feb 21, 2005
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    First off I appreciate all the help and all the advice. I'm ashamed of myself with my scatterbrained method of troubleshooting but this car has got me all over the board trying everything possible to no avail. The new camshaft position sensor made no difference at all whatsoever. So basically right now what's going on is the car will start cold in the morning, but will not restart at all afterwards. The passenger side Bank 1 through 4 floods out immediately to the point where it renders the car non-functional. I'm talking about raw fuel dripping out the flange where the exhaust meets the cat! Spark plugs completely soaking wet. Ironically there is Spark, and with everything that's been replaced timing should be spot on so therefore it must be in over fueling problem causing significant flooding. So now my latest theory is that the injectors 1-4 are bad and leaking profusely so I have eight brand new injectors showing up tomorrow and will install, test and report back. New information however that's relevant I did a compression test all cylinders are approx 125 a little low but at least consistent. Timing is spot on. I removed the top cam covers, achieved top dead center and verified the timing marks we're lined up spot on, Palm Beach Perfect with the cam marks and cam sprocket marks perfectly aligned which is incredible news. Sprocket nuts nice and tight not loose. As far as the voith clutch I did repack it last year I did however use SuperLube Synthetic grease but I am quite sure this is not my problem because number one the car never even warms up to any operating temperature of consequence which would cause that clutch problem and there is no noise or racket at startup or shut off. Will report back after I install the new injectors.
     
  20. m.stojanovic

    m.stojanovic F1 Rookie
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    So, it appears that you have narrowed it down to flooding in the bank 1-4. A couple of possible reasons:

    1. The spark is present but insufficiently strong, or at the wrong times, to ignite the mixture. Do you still get code 4112? If yes, you would need to check the wiring from the Cam Sensor loom side connector to the engine ECUs (the pink wires).

    2. The operation of the injectors on the 1-4 bank is erratic, perhaps they, after start-up, all open and stay open due to a possible fault in the engine ECU. You said that you swapped the engine ECUs and that it made no difference. But did you verify that the flooding still remained on bank 1-4, i.e. that it did not move to the bank 5-8 ?

    If you have flooding on all 4 cylinders, it is unlikely that all 4 injectors have gone bad. And your test showed that they are not leaking.

    You will need to read the fault codes after every change and/or trial during your diagnostics and also make sure that you have read all codes. You have to manually move from reading one code to the next one (forgive me if I am saying what you already know). I have attached the code reading procedure, just in case.

    A separate quick check - make sure that the two ground connections on the RH cam cover are clean and not loose:

    Image Unavailable, Please Login
     

    Attached Files:

  21. Portofino

    Portofino Formula Junior

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    Swap the fuel regulators around .
     
  22. POLO35

    POLO35 Formula Junior

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    Yes sir although it's been two weeks of troubleshooting I feel like I at least have it narrowed down positively. It really appears that the significant flooding is cylinders one and two. I have cleaned those ground points on the valve cover they are squeaky clean and shine like a diamond. Even ran a tap in the hole to clean the threads. When I initially tested the fuel injectors it was with a cold engine when I did my water bottle test. I suspect that once the engine warms up to any level that that might possibly be causing the injectors to leak or drip. Just a theory but I certainly don't feel comfortable testing with a hot engine and open injectors....too dangerous. The injectors were cheap enough I'm just going to replace them one through four at first and test... easy enough...cheap enough. I will definitely report back. I will have a look at the loom frin CPS although I don't want to go cutting into it just yet. The plug end looks perfect. As far as fpr's they are working perfectly at 54 PSI on 1-4 and 50 on 5-8 with no dripping fuel from the vacuum nipple. And just to reiterate over the last two weeks I have essentially swapped every single component from passenger side to driver side including the ecus and it did not follow. However one thing I never switched was the camshaft position sensors but I did that and the problem did not follow. I had replaced them with the Kia sensors but since that made no difference I went back to the OEM. But I had never tried swapping them just on principle. Will definitely post results with the new injectors..... fingers crossed.
     
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  23. POLO35

    POLO35 Formula Junior

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    #98 POLO35, Feb 16, 2025
    Last edited: Feb 16, 2025
    Correction on that last post what I meant to say was one thing I never did was switched the OEM crankshaft position sensors to see if the problem followed. I accidentally typed in camshaft position sensors. I had replaced both with the Kia sensors and it made no difference so I went back to OEM but I had never actually just on principle tried switching the oems just for the heck of it to see if the problem followed and it unfortunately did not. By the way this is what 33-year-old original injectors look like from a 33,000 mile car! Took this picture last week when I initially pulled them. Unbelievably they had a pretty darn good spray pattern. But still hopeful that this is going to be the final fix.
     

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  24. POLO35

    POLO35 Formula Junior

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    Well I promised I would report back and I fitted the cheap aftermarket injectors and I guess you get what you pay for... car actually ran worse! But the consistent problem still persists. Which is bank 1 through 4 is running slobberingly rich flooding out sputtering and backfiring. I'm going to thoroughly clean the OEM injectors, reinstall and retest. I know this is probably stupid and a waste of time but I want to see if there's any Improvement just from cleaning the OEM injectors. As you can see from the photos they were absolutely Dreadful. Of course I'll fit them with new O-rings however the originals surprisingly are still Supple and soft which is really amazing. I will report back ASAP.
     
  25. tbakowsky

    tbakowsky F1 World Champ
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    I hate to go back to this, are you 100% sure the cam timing is correct? I know you mentioned you checked it. But it may be worth pulling the valve covers and verifying before you continue spending good money after bad.
     

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