F115: how to test ECU ?

[loyoki]

F115 2002: sneezes at idle, rattles, like 1 or 2 cylinders missing and sometimes died. TPS is new and 0,733V adjusted. It starts at 800-900rpm but after running 5 mins it comes to 600 or 500rpm and died. Engine starts without error code but with ignition advance: I heard this famous clicking sound (clickety, clatter). When I throttle and run 5 or 10 mins at 4500 rpm, clickety seems to stop, engine runs fine up 5600 rpm and when i come back to neutral, engine dies.
I think it is ECU that gives a bad timing ignition, how I could test it ?
Is it normal to have ATDC 4 deg at iddle and BTDC 15 deg at 3000rpm ?

DIAGS at IDDLE:

Engine Monitor,
,Monitor Item,Result,Unit,
,Engine speed,875,r/min,
,Intake pressure,544.0,HPa,
,Intake pressure,16.10,inHg,
,Atmospheric pressure,1013.5,HPa,
,Atmospheric pressure,30.0,inHg,
,Ignition timing,ATDC 4,deg,
,Battery voltage (12-16),14.80,V,
,Throttle valve opening (0-90),1.6,deg,
,ISC valve opening (0-100),76,%,
,Fuel injection duration,2.29,ms,
,Water temperature (below 90),52.5,°C,
,Water temperature (below 194),126.5,°F,
,Intake temperature (below 70),35.5,°C,
,Intake temperature (below 158),95.9,°F,
,Oil pressure switch,OFF,,
,Engine stop lanyard switch,OFF,,
,Shift position switch,ON,,
,Dual engine system switch,OFF,,

DIAGS at 3000rpm:

Engine Monitor,
,Monitor Item,Result,Unit,
,Engine speed,3080,r/min,
,Intake pressure,456.2,HPa,
,Intake pressure,13.50,inHg,
,Atmospheric pressure,1013.5,HPa,
,Atmospheric pressure,30.0,inHg,
,Ignition timing,BTDC 15,deg,
,Battery voltage (12-16),14.60,V,
,Throttle valve opening (0-90),6.3,deg,
,ISC valve opening (0-100),100,%,
,Fuel injection duration,1.98,ms,
,Water temperature (below 90),48.0,°C,
,Water temperature (below 194),118.4,°F,
,Intake temperature (below 70),35.5,°C,
,Intake temperature (below 158),95.9,°F,
,Oil pressure switch,OFF,,
,Engine stop lanyard switch,OFF,,
,Shift position switch,ON,,
,Dual engine system switch,OFF,,

THANKS

[99yam40]

If I was you I would search and read Rodbolt17 posts to see if you can get some info out of them, seem like he has posted on some of the F115 problems and what to do.
Maybe he will step in and look at your post

[rodbolt17]

your ISC numbers at idle are wrong.
idle speed should be about 750 in N and the ISC opening in the mid 50% to about 65%.
your intake pressure numbers at 3000 RPM are either off your your revving it in N which is useless at best and harmful at worst.
doesnt sound like the ECU is failing and yes those timing numbers are about right.
try the dynamic ISC valve test.

[loyoki]

Thanks Rodbolt17,
- Yes I know my idle speed is too high
- Sorry but I don't understand "are either off your your revving it in N" ?
It means intake pressure is not good at 300rpm ?
On YDS software (1.3), I can't access the choice to do a dynamic test of ISC, perhaps my ECU is too old.
Before my TPS broke, I thought it was the ISC faulty, however I heard ISC rattled during 2s after switch off engine.
Another way to test ISC ?

[rodbolt17]

if TPS voltage is off or the idle speed is to high it wont allow the dynamic ISC test instead you get an error message.
the sneeze is most likly a cyl running lean.
double check the shutter adjustments but 75% ISC command means the ECM is trying to correct for something.
ign timing can be checked with a standard timing light.
cannot be adjusted but it can be checked.

[loyoki]

With YDS I have only access to 1) SCAN TOOL > 1) Diagnosis 3) Engine Monitor, all others functions are unavailable.
If I turn the visible screw (#3 on INTAKE 2 diagram) for opening shutters, it affects TPS voltage, ISC opening too ?
There is another hidden screw (#4 on INTAKE 2 diagram) on shutters, what is its purpose ?
Thanks

[Shon.webb]

I Know this is a old thread but I’m wondering if you ever got this figured out. I have a 2002 f115 with nearly the same exact symptoms. I’ve replaced the iac valve but that didn’t help. Did you end up replacing the ecu?

[boscoe99]

I Know this is a old thread but I’m wondering if you ever got this figured out. I have a 2002 f115 with nearly the same exact symptoms. I’ve replaced the iac valve but that didn’t help. Did you end up replacing the ecu?

Whatever fixed the OP's problem might have no relationship to a fix for whatever your problem is. The exact same symptoms can be the result of any one of a number of completely different problems. Thinking that whatever solved one problem will solve a similar problem will send you down rodnuts rabbit hole.

Better to start a new thread and describe the problem that you are having.