Hello, Some weeks ago i changed the steering rack on a Mondial T and had the radiator rebuild. Car came in fine, but now it almost doesn't want to start when it's warm. Cold start, running and driving like a charm, but when trying to start with a hot engine it just won't fire. The starter motor works perfectly, first it's just spinning around after 2 seconds you hear it's a bit backfiring/firing at the wrong timing. The crankshaft sensors both give steady measurements, both in resistance cold and warm as in AC voltage while starting. There is on one bank a camshaft sensor(i presume) on which i can't get a descent reading. Has anyone got more information on this sensor/or the ignition system or are there other things known to cause this? Thank you! Ruben
I think Ferrari calls it a phase sensor but I think you have called it correctly as a camshaft position sensor. I think it is a Hall Effect type sensor but I have no other specific info on it. It may be more to it than I understand.
I suggest it might be bad/leaking Fuel Pressure regulators. This seems to be the only thing that causes hot start problems on the T's and 348's(?). Check this out: http://www.ferrarichat.com/forum/technical-q-sponsored-algar-ferrari/121977-how-change-fuel-pressure-regulator-348s.html
Flywheel grease, who would have thought (as one potential problem). But a grease "failure" can cause an imbalance which generates vibrations that could be picked up as false signals... Lots of reading ahead: http://www.ferrarichat.com/forum/search.php?searchid=9622666
Contradictory I know, but try holding the pedal to the floor when cranking. I bet that will work for you. ;-) Alden
I had a similar problem with a motorcycle. It wouldn't start, them BOOM ! backfire. It turned out to be dirty spark plugs. Try replacing the plugs, or clean them with a torch. https://www.youtube.com/watch?v=dYwSObeCaUY
Apparently Ferrari Chat doesn't "remember" search results. Keywords in the 348/355 forum: 348 hot start flywheel
Thank you for your replies. The cold start is not 100% but it starts, although it takes long. There is an aftermarket pressure gauge fixed and it immediately jups to 2.7bar when cranking. Driving is 100%, she had some coughs but they're all gone. Have driven it slow, have driven it hard, no issues. Starting it back up when hot is near to impossible, no matter how you try it, it has to cool down. Plugs are new. From what i read, all the flywheel grease problems are present so i don't think i'll have to look much further. I already heard someone talking about it but the story was so vague i couldn't make heads or tails of it, now it's clear. I'm going to try removing the alternator because it stopped charging (and make the tachometer go berserk...) to be sure but if the problem is still present after this i'm pulling the flywheel.
Before condemning the flywheel, check the vacuum hose connection on the fuel pressure regulator(s). Pull off the hose when running or immediately after shutdown. If it dribbles fuel, the regulator is broken. This fuel will flood the engine when it is standing still after shutdown.
That's a good point and there are two of them. Top of the motor towards the front. FYI, the vacuum hose leads to the intake plenum. These threads may help with that: http://www.ferrarichat.com/forum/348-355-sponsored-bradan/170224-348-hard-start-problem.html http://www.ferrarichat.com/forum/technical-q-sponsored-algar-ferrari/457779-348-fuel-pressure-regulator-upgrade.html . Image Unavailable, Please Login
Checked the regulators a while back, no fuel comes out and i can put a vacuum on them so they don't leak. The latest time she also start to start difficult when cold. (was gone for a while but is back now) Tried with the engine running to disconnect the ignition modules next to the coil packs, when i disconnect the left one, the engine runs a bit slower and not that rough, when i disconnect the right one the engine immediately drop a lot in rpm, start to run really rough and after 1-2seconds shuts down. I thought they ran completely seperate the left and right bank? When mesuring the voltage at the fuel pumps, the get a 9.60volts when running and 6volts when starting the engine, which seems way to low for me. After putting 12v directly on them the car does start when hot after crancking a couple of times (not good but before it just wouldn't start.) Are there electrical drawing available somewhere? What fuel pressure should there be when cranking/running?
If you are having problems starting from hot , it looks like you are vapour locking the fuel pipes due to the residual heat in the engine bay- if you look at the fuel system diagram you will see a non return valve on the outlet side of the electric pump, also after the fuel pump is an accumulator, then the fuel filter. When the engine is stopped the fuel pressure at stop is maintained in the system by the trapped pressure in the accumulator. This maintained pressure stops patrol vapour from forming in the pipes, with no fuel flow and the heat in the engine bay the pipes heat up- if not enough maintained pressure then you have vapour forming in the system that the injection pump cannot deal with. Either the n/r valve is leaking back or the accumulator has failed. When you get it running it would show the fuel pressure is fine as it is pump discharge pressure. Look online for a Bosch k tronic fuel injection system, gives a good diagram and info how it works. If you have a bank misfiring along with fuel raising the sump oil level then the diaphragm in the injection system is split. This model is prone to cutting out after you approach a junction , no servo etc- a good slug of injection system cleaner in the fuel tank usually cleans up the injectors. Other fault can be a coil pack breaking down, car starts up ok and starts missing on 1 bank after a few miles-to find start car from cold and drive until it starts to misfire-jump out and put your hands on both coil packs, 1 will be warmer or hot and other one is cold. The cold one is the good one. As the coil gets more miles on it, it gets hotter and the insulation starts to fail, hence the misfire. This relates to my mondial 3.2 so it should be similar
Bingo, that is your problem! I can send you a PDF of the electrical diagram you need, just PM me your email address. Alden
Ferrari, the factory dealership in SF had a fix for this on our Mondial T, it was a booster part to the starter $80 fit under the steering dash area. Seems the solenoid gets too hot at times and you are stuck...as we had many times waiting for it to cool down. This may not be the same issue as you describe, but def solved our problem. was very embarrassing to sit somewhere after a spirited drive waiting for the cool down.
Hi everyone, thought i'd post the solution here. The low voltage on the fuel pumps was the cause of the cold start problem. Cleaning the terminals was enough to have it firing up decently(not perfect) The Flywheel grease problem was the cause of the hot start issue, after ordering the O-rings and new grease it only took a couple of hours and the problem was solved. Also the rattling sound as described often was gone afterwards.
