help.. half my 348 motor shuts down

Crank sensor?

 

See my post on the Mondial forum "Left bank running rich". The Mondial T has the same engine as the 348 I am told.

 

https://www.ferrarichat.com/forum/posts/146929886/

Mostly the same. Meaning differences in the ignition system i.e. Motronic 2.5 or 2.7. For example, here's the earlier version. Notice only one TPS.


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Can you identify which bank? Any slow down lights or CELs on the dash? Can you pull any codes? ( maybe no bulbs fitted) If not my first thing would be to disconnect the cat ecus and thermocouples just to take them out of the equation before digging deeper. Few seconds work. Many years ago I had a very similar situation at start up from cold. About 5 mins or so in it dropped a bank. It was a cat ecu. Didn't even get up to full temp. I run decat pipes so I left it disconnected.

 

I had a bit of trouble following your dilemma as described (run-on sentence without punctuation). So I broke it down... did I get it right?

Car starts up and runs fine for about 5 minutes then sputters a little and the whole side (i.e. one Bank) goes out.

I have switched MAF sensors from one side to the other and the same thing happens.

I have changed fuel filters, spark plugs, checked the spark, installed two new O2 sensors and took apart and cleaned the throttle bodies, but it still keeps happening (just on one half of the motor)

On the half that goes out, if I take the MAF plug off, the motor stays the same.

If I go to the other side and take the MAF plug off, it dies right out.

Anybody have any suggestions? Any help would be appreciated.​

 

My car was recently dropping a bank when driven hard. It was the 5-8 side and was the crank sensor for that bank. It was not that bad to change and the 5-8 side is the difficult one.

 

I went from underneath with a small Allen key once the bolt is broken loose it’s easy to change. I didn’t have a lot of leverage to loosen it but it is doable.

 

bad ground? dirty connector somewhere?

sjd

 

I had the same issue awhile back and what worked for me was unplugging the tps on the bank that drops and sprayed contact cleaner on both the plug and the socket. Disconnect the battery first.


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You can get the crank sensor very easily andnin a fraxtionmof the time from the passenger wheel well if you remove the liner with a 1/4" 2 foot extension and a swivel.

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If your Cat ECUs are disconnected and from what you have said:
- its not your MAFs;
- its not plugs/leads/o2 sensors.....

next just replace the crank sensors (cheap from Kia; see master sticky).

If that doesn't cure it you need to start swapping parts etc;
- clean all electrical connections with cleaner
- swap relays for ECUs;
- swap relays for fuel pumps;
- put a volt meter on your fuel pumps to see if one of those is being temperamental;

- swap your ECUs over ;
- check earths.

If none of that finds an issue, then replace the following (not overly expensive)
- power modules and coils;

If none of that works, come back for more help; and hopefully somebody with some deep understanding will step in!!!

Good luck. I've had similar issues and feel your pain/hassle. For me 1 incident was Cat ECUs, and another was crank case sensors.​

 

Check fuel pressure and check to see if injectors are firing.

 

Another place to check are the 6mm screws near the driver cam cover, I can't remember if they were on the top or the bottom but the grounds
for the motronic 2.5 are tied there. And of course, do you have any way to verify fuel pressure on the dead side?

Jeff Pintler
89 348tb, 86tr, 99 360 3pedal, 05 S-160 Bobcat

 

I'd switch maf, coil and ignition module from one back to other and see if problem changes banks. No cost and takes 20 min.

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