355 Explanation of secondary air and vacuum system

Sure might take a few days
I feel the same way because of work it’s been many weeks between things

 

Changed fuel press Reg no change in running
Changed all o2 sensors Nno change
Smoke tested intake no leaks. No change
Checked fuel pump for volume and was at the higher end of good. No change
Changed fuel filter No change
diagnostic sheet 22 page 1 and 2 checked all injectors and they are in spec and everything else checked good except
#17. Supplementary fan control winding and #19 supply of voltage to air injection pump control relay (but air injection pump works as designed)
Pg 3
Maf sensor also seems to check out at 1.35 when engine idling
Static check of cam timing sensor has 12 volts to both signal and power. Signal pulls down when touched with iron file so likely working
Changed all spark plugs on bank 1 no change
Replaced all plug wires with old working ones. No change
Removed injectors and tested 3 injectors are all the same injector 3 is flowing about 10 percent more but unsure if that would cause enough of a problem
Tried cleaning them but it did not seem to help much
Replaced idle air control since I had a know old working one. No change
Unplugged bank 1 knock sensor car ran slightly better then way worse throwing permanent sdl which before would only be flashing after an acceleration
removed bank 1 plenum checked butterfly’s and did a visual on linkages etc all looked good

if I remember anything else will add another

 

The throttle position sensor was checked and varies consistent with the opening of the throttles

 

My 2c-worth. The ECU can adjust injector opening times by up to +/-20% in response to O2 readings, but the fuel adjustment is probably based on an average of 4 cylinders (one bank). If one cylinder has too much/too little fuel due to a faulty injector, the ECU would try to compensate: With a single faulty injector, you would be underfuelling/overfuelling the good cylinders by a few percent and not adjusting the fuel on the bad cylinder by a long way.

Does your injector tester run the injectors at max flow?

Strange. The "supplementary fan control winding" is the RH radiator fan relay coil. How far off were the readings?

 

So the issue is Bank 1 is running with long term fuel trim way too high and sometimes it would cause a SDL and shuts down the bank, correct? Poor running when you smash the throttle, correct?

You have tried to chase down issues that are bank specific, such as:
Spark plugs
Fuel pressure regulator
Ignition wires
Unplugging knock sensor
Throttle position sensor
Injectors
Intake manifold smoke tested
Exhaust manifold tested.
O2 sensor

You have not done:
Ignition module
Replacing ECU
Compression test
Leak down test
Secondary air injection check valves at the exhaust headers

I find that sometimes it helps to go back to very basic things. Do a compression test on all eight cylinders and see what numbers you have. That will also tell us if your cam timing is off on one side and not the other. Did you check the operation of the two one-way valve at the secondary air injection ports of the headers? Are you sure you did not get the two connectors swapped at the vacuum control board behind the passenger rear wheel?

 

Yes did changed coil but have not checked 3 wires but have used a timing light and all cylinders are sparking at idle but could fail under load
The rest you stated is correct have not done those
Replace ecu
Compression
Leak down
Sec injection air valves

But did have cam cover off day timing marks still line up on that bank

I can hear a bit of a flutter when accelerating sometimes

 

Yes I can run my injectors at up to 60 psi and 8000 rpm
Sup fan control was way off almost zero.
From memory I think 0.315 ohms
Actually maybe it was volts and supposed to be 12

 

The Ferrari spec sheet says 11~13 volts. I don't know what 0.315 ohms would represent. The relay coil resistance should be in the 10's of ohms, not milliohms (although I don't have any specs for that particular relay).

 

Grant,

If I remember correctly, you had to replaced one used head. Was it on the bank that is now giving you trouble? Is there any lifter noise? Did you check the valve lifters while you have the engine out? Did you degree the cam shafts to specs? Humor me and ... perform a complete compression test on all cylinders.

 

It was volts Ian
Sorry gettin old ha ha

 

Yes that side
Yes I checked everything on the head and it checked out
Yes I did the cams you and fbb helped me lots on that and they are still perfect as I had the valve cover off.
Everything still looks good there

remember once in a while it kicks in and works perfect for a few seconds from 1200 rpm but very sporadic and only one out of 30 tries likely
It also pulls hard above 7000 rpm wide open in 3 4th and 5th to 240kmh

 

Not that I would ever go that fast
I am working out of town so just back for the weekend no time to wrench for a bit but thank you to all the help
Will try some of the things mentioned and get back to the group

 

So 0.315 volts? Something definitely fishy there. The radiator fan relay (R) coil is supplied with ignition volts, so if you are measuring across the correct Motronic ECU pins (62 and 55), you should be getting ignition volts. Oddly, the diagnostic sheet says if you are not getting 11~13 volts, it says to check the protection fuse. There is no fuse.

Recheck memory

 

I may have too will have to wait for our long weekend coming up
I will keep you posted.
On another note that electrical schematic you sent me is it for a 5.2 as I am assuming it was just not an F1??
Or I wonder if they are the same?

 

I've forgotten which diagram I sent you. The main Motronics 5.2 diagram is different for the F1 and non-F1. There is an extra plug on the Motronic ECU on the F1 car. i.e. the databus plug hooked up to the F1 TCU.

https://www.dropbox.com/t/TSOLzfhYiVBmDKUP

The associated diagram which shows the interface between the smaller Motronic plugs and the rest of the car (relay panel, instruments, exhaust bypass, secondary air, etc) is not complete for the F1 car... It has non-F1 instrumentation:

https://www.dropbox.com/t/TSOLzfhYiVBmDKUP

I could add F1 instrumentation, but it would only be theoretical and there would be lots of unconnected wires:


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So I had a spare ECM so I plugged it in and it worked perfect for about 3 minutes then the same.
I think once the computer started getting signals under closed loop the parameters started getting closer to my original computer because when I scanned it
Using live dater the fuel trims were normal but we’re getting richer all the time on bank 1.

I think this would tell me that mechanically the engine is good I just have a problem with the amount of fuel and need to figure out why.

 

Is disconnecting the knock sensor a valid diagnositic method? Is "open circuit" the equivalent of no knock ... or does the ECU just add fuel because of a lack of any signal?

Does your scanner give a knock count (and can you compare it with the other bank)?

The knock sensors look really hard to get to, especially the right one.


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I suppose you could plug a new one into the harness to see what happens (maybe attach it to something on the right bank rather it than floating in the air).

Bosch P/N0 261 231 007.

 

According to the manual if you have a faulty one you can disconnect and if everything else is good the engine will run fine
From what I read.

 

That being said when I plugged in the new computer I also disconnected the upstream and downstream o2 sensors.
This is also supposed to make the computer run open loop but the car would start fine but slowly start to be too Rich and die
After plugging them back in it idled perfect and ran perfect for the 3 minutes as stated above.

 

Mitchell has been a huge huge help over the phone and email
I finally got an oscilloscope that works and I have a power problem to injector 2 and 3
Which is exactly what Mitchell was suggesting I just had no real way to prove it.
It’s intermittent and when I checked cylinder 4 it even went from not working to working right on the scope

it took a while as I had to order and make a few pigtails so I could test while the engine was running.

still working through what the problem actually is and narrow it down as to where in the harness or plugs it would be
On Ian’s diagram power splices for injectors is at 30009 but I have no idea where that is so any suggestions would be good
I will keep you posted as I go through it

 

I just realised that I labelled the wire gauges incorrectly on those power splices. They should be like this:

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Corrected F1 diagram here:

https://www.dropbox.com/t/eKbl5JTN8cgciH9f

Unfortunately, it looks like the fattest part of the bundle contains the splices (see white arrow.... ignore the white circles).

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Does the injector harness split into two branches on both sides, like this?

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or is it simply like this:

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Unfortunately, I gave away my old broken harness, so I can't check where the splices are.

 

Not sure I could tell
They do come out in pairs though

 

Maybe I should check the plugs first since I installed gold kit myself

 

Does not really make sense that the harness itself would have a problem as it has not been taken out

 

So probably the first diagram. Then if the problem is on 2 & 3, it must be before the branches (and in the thickest part of the harness) or as you say, individual problems with connectors.

By "taken out", you mean removed? Harnesses get stretched/damaged during engine-outs and we still don't know how far back the splices are.