Engine issue with 355 challenge

I have owned my challenge for 8 years. Mostly use it on the road with the odd track. Hasn’t run much ober the past couple of years due to Covid, last engine out service 2 years ago.
I took it to my mechanic for an oil change. Car was running great beforehand.
I had to pick it up and, ehile driving back home, quickly realised something was amiss. Car had no power, in neutral, slight press on throttle resulted in rev dropping. Very difficult to rev up. Sometime engine would come back to life for short periods of time. I have the impression one banck isn’t firing.

I am now waiting for the car to be collected but this will bave to wait as the workshop is full and car is kept in my second home.

I wanted to pick the brain of the experts as I have tried troubleshooting the issue. The car starts notmally with both CEL coming off 1-2 seconds after start.

I don’t think it’s fuel supply related as fuel pump and lines were changed as part of last engine out service.
I immediately thought it may be the ECU relearn as I drove the car stright away and they may had switched off the battery. Did it properly but no improvement.
I have checked battery voltage, but it on conditioner overnight, no result.

I have cleaned up the contacts at the 2 engine ECU in the rear wings. No improvement.

I am now thinking it may be a sensor that failed. They are probably original and I guess eventually they are bound to let go.

Any thought ?

 

Could be a problem with the coils or spark plugs ?

 

Just engine oil? Does your mechanic know how to change oil on Ferraris?

 

How old is the fuel? Since you don’t drive much

 

Fuel is likely not suspect as he mentions "I took it to my mechanic for an oil change. Car was running great beforehand."

See quite a few of these threads, basic oil change then the car won't run right after for some reason, Perhaps mechanics trying to drive more work back into the shop post oil change.

 

Thank you for your thoughts:
Spark plugs were replaced during enfine out service. Not likely to be the issue. Coils: hard to check, I check the ignition box side of the cables but didn’t go as far as removing the cover on the engine to check the coils.
Fuel has been in for some time but wouldn’t only affect one side of the engine like it seems to be.

the workshop I use has plenty of work (they had a couple of classic lambos in restoration and a matra V12 70s formula 1 in the shop together with other exotic machinery), I doubt they are just creating issues to get more work. My car is somewhat of a diversion !

 

I wouldn’t cross out fuel just yet, as I’m talking about water separation from ethanol fuel. As water accumulation will rest on top of the fuel. It could run fine until the fuel level drops.

high ethanol fuels, high humidity and long sitting periods. It is quite possible.

I heard the UK now sells E10 when it used to be just E5?

 

What year is the car? If it's a 2.7, that sounds a bit like 1 ECU not having power.

 

Did they wash the car or detail it before you picked it up?

 

Water goes to the bottom. Additionally, separation in E10 can only occur if the fuel is saturated to start with and then the temperature drops. Other than that the only way to get water in the tank is from condensation.

Consider that the 5-8 bank crank sensor is mounted on the bottom and not too far from where they would have been working to remove the drain plug.

 

The car is kept in south of france. Very dry and I only fuel with E5 / 98. So less risks than with E10.

all challenges are 2.7. If one bank ECU wasn’t getting power, wouldn’t I get a CEL ?

when looking at the car from rear, is 5-8 on the right hand side or left ?

 

Are you sure a bank is dead? Very easy to check with a laser thermometer on the headers. If you're certain it's a bank problem then you've significantly winnowed the list of culprits.

 

If you have a true Challenge car, then it has some extra stuff and does not have some normal 355 stuff. Take anything I say with a grain of salt. Start with ...

Run the car at idle, use a laser thermometer (get one if you don't have one) to measure the temperature at the exhaust header for each of the cylinder. See which one is not firing.
Bank 1 is the right bank, bank 2 is the left bank.
If one whole bank is not running, all the cylinders on that side will be stone cold.
If it's the whole bank not running, start looking at fuel pressure for that bank, or ignition for that bank, or TDC sensor for that bank.
If one or two cylinders are not firing, then you have to focus on those cylinders. Since you took the car to a mechanic for an oil change, my guess is you don't want to get your hand dirty at the dead cylinder level. Take it to a shop.

 

Yuuup, Sounds like fuel
I had a pump drop on the track, hit 7000rpms car went flat. Got worse until I could not go past 4000rpms
Run my pumps out of tank now for easy servicing.
BTW had this happen on 2 of my 3 challenges
Car sitting for a while is a pump killer for sure

 

I had the pump replaced 2 years ago. Could it fail after such a short period ?
Perhaps. Will report when they get the far back.

 

Yes very easy. When they sit they tend to corrode from the bas gas these days, even with that fuel additive sitting kills it. I been replacing fuel pumps in my cars that sit for years for the last 40 years. Cars sitting is the worst thing for them

 

I don't see that you mentioned if it's single or dual fuel pump.

Not sure but would guess Challenge cars followed street cars when 2.7's went from dual to single fuel pump?

If so and dual pump, of course one pump failing could kill a bank.

Would say johnk's crank sensor idea is the most likely/logical.

 

A fuel pressure guage is quick and telling

 

My challenge has a single pump. It was renewed recently.

 

Follow yelcab above and get back too us. All these checks are relatively easy.
If 1 bank is not running switch the coils from bank 1 to bank two is about all I can add