Need Help_RH misfiring after engine out

Has your mechanic worked on 355 before?
Is this a 96-99 OBD2 car or 95 OBD1 car
A little more diagnostic BEFORE you took the engine back out would have been a lot more useful, seriously. Right now, all you can do is guess.

What is the misfiring? the whole bank shutting down, or one / two cylinders misfired?
How did you / he check the cam timing? With a degree wheel, or eyeballing it?
Did you use Hill Engineering tensioner bearings? Did you make enough clearance for those?
If OBD2, did you plug the TCU bank 1 back into the right position?

 

Agree with yelcab. It's going to be impossible to diagnose with the engine out.

While it is out, I would re-check all connectors, make sure they're cleaned, and that none of the blades or receptacles are bent or loose. When the engine is in, pull codes from the ECU. On OBD2, it's an OBD scanner, on OBD1, you hold the giant pin by each ecu between 3-5 seconds, release, then count the flashes on the dash.

 

Diagnose then disassemble.

 

Might be the Gas Cap. Try a new one.

 

Looks like a 95. Only 1 O2 sensor in the test pipes. But note how much carbon in the test pipes and muffler tips (both banks)? Fuel delivery/ignition comes to mind. Good luck figuring that out with the engine out.
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It is possible to get engine sensor plugs swapped. However, swapped sensors would probably throw a code. Motronics ECU to sensor wiring has to be buzzed out to confirm correct fitment.

When I couldn't get my car to run after an engine harness replacement, when doing wiring checks, we found that some of the chassis/engine earths had relatively high resistances. I would check your earths. Sometimes high temperatures in the engine compartment can affect resistance: At another time, I had a loose earth above the left hand radiator and every time the car heated up, the turn indicators on the left side of the car started playing up. This was a common earth for half a dozen different components, but it only seemed to affect the turn indications.

 

If I am correct that the car is a 2.7 (95) then it's possible that the problem is with a bad connection to the 1-4 bank crank sensor. I had a misfire in my car that was intermittent and only happened at 4k RPM and above. Turned out to be a wire from the 1-4 crank sensor that was broken internally at the engine connector crimp. An SOB to find but finally found it by tugging on the individual wires at the connector. When one wire stretched problem solved.

Still, there seems to be an awful lot of carbon buildup in the exhaust, even considering that the cats are gone.

 

Gas cap?

 

He was just throwin* out guesses s8nce that seemed to be what others were doing

 

Figure out which cylinder is misfiring. Inspect the plug and wire. You may just want to pull all the plugs and wires and inspect them. Test the wires as well. The wires run inside the valve covers, and take a beating with all that heat. Failures are not uncommon. It might even be worth throwing a new set at the car, if yours are original. Kingsborne are reasonably priced...or were the last time I bought a set.

 

I know kings bornes name is thrown around a lot but I think ricambi sells sets and they are not much more

 

Which fuse?

 

Appears to be the LH radiator fuse. Wouldn't think it would be the problem unless the melting is causing problems with the circuit board and effecting the fuel pump connection.

 

Looks like fuse pump. Might be time to look up Dave Helms fuse panel modification with all that melted plastic.

 

The fuse is green = 30 amp = radiator fan fuse. But, yes, like I said, melting could effect fuel pump connections.

 

I'd be curious to know why the problem started after the engine out.

 

If that is the case, I would recommend the OP search for my post about 355 radiator fans. He will need to replace his fans, as they are obviously old and now drawing excessive current. My thread has information on oem SPAL replacements (at lower cost than from Ferrari), or the option of using a lower amperage SPAL fan that works very well and will prevent further damage. But as you surmise, it may be too late for that fuse panel.

 

Here's a thread on SPAL fan types:

https://www.ferrarichat.com/forum/threads/355-fans-replaced-with-spal-30102113.526398/

Of particular interest is this post (in the above thread)
https://www.ferrarichat.com/forum/posts/144782091/

I wonder what causes the fans to start drawing too much current? Bearing resistance, motor brushes worn?

 

Thanks, this is the original thread I started, and was quoted from in your post above:
https://www.ferrarichat.com/forum/threads/new-updated-f355-radiator-fan-information.300662/

 

There may be a fan problem, but it appears the fuse is not being blown so the fan would not appear to be drawing excessive current. The melting is more likely the result of corroded or dirty contacts at the fuse causing excessive resistance, therefore heating. This is a common problem with the old euro style fuses in 308s.

Anyway, need to examine the fuse panel to see if it effected fuel pump connections. Since the engine runs fine cold, I question that this is the problem with the warm engine miss.

 

Actually John, it is from the current draw. While the fuse may not be blown, it is running right near the max, and the fuse panel simply cannot handle that load. It is a well known (and common) problem with the 355 and why Dave Helms came with a modification to the factory 355 fuse panels. It is very common for the radiator fan circuits, and the fuel pump circuit. I believe Dave's modification moves both circuits to a separate panel that can better handle the load. (btw, are you certain that is not the fuel pump fuse? I ask because I thought the left and right hand radiator fan fuses were adjacent to each other. But I haven't had my 355 in several years, and my memory is not clear )

If you read the thread I started (and mentioned above), it was found the oem SPAL radiator fans are rated (new out of the box) as drawing 27.5 amps, on a 30 amp circuit. The start up current is obviously much more, though only for a very short period. But as the fans wear, the start up and running current simply gets higher and higher causing all of the melting, and blown fuses. More details on why the fans do this, and options to prevent it are in the thread...

 

Well, then I won't speculate about the cause other than to say any heat generated comes from I^2 R, so if the fuse isn't blowing the max current should be below the design spec and that leaves excessive resistance locally around the fuse/board interface since that's where the melting is.

Either way, we are off topic and as the OP hasn't chimed back in we can't know for sure if this is relevant to the original problem.

But yes, the fuse pulled and the melted area are the LH fan. The other fan fuse is above to the right in the picture. The only 30 amp fuses in the boards are for the fans.

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