Ford 5L V8 - Monsoon - Hot start / running problem.

[Cam_the_comie]

I'm helping a mate with a Ford 5.0 EB-II V8 running a monsoon ecu. It runs beautifully when started and continues this way until the IAT reach's above 70'C. It then starts missing, until it finally stalls. It will then not restart until cooled down for an hour. The problem looks too be ignition related, so the original Ford TFI has been removed and a new hall sensor on the distributor wheel is feeding the trigger signal with a new ignitor & coil having been installed also. When this problem occurs the IAT in the runtime values flags as an alarm state. The log file has trigger errors when this happens but the ECU and Fluke Scope on the trigger do not show any problems.

Checks done:

* ECU scope & Fluke Scope check of trigger signal when running. Good.

* ECU scope & Fluke Scope check of trigger signal once stalled and trying to restart. Good.

* Fluke Scope of firing signal from ECU to ignitor taken at the ignitor plug when trying to start. No signal.

* Fluke Scope of firing signal from ECU to ignitor taken at the ignitor plug with  ignition test. Good.

* Spare spark plug connected to coil and earthed out in both examples above and will only spark on ignition test.

* Any ignition cut or protection has been turn off too fault find. 

Attached is the setting file and the log file.

Any idea's are welcome!

Thanks, Cam.

Ford-EBII-5L-V8-Monsoon.pclx LOG - Ford V8 .llgx

[Adamw]

Do you have any scope captures from when the trigger error is occurring?  Preferably from the ecu triggerscope initially as this has the trigger status info that tells us what the engine position processor is doing.

In that log the battery voltage is a bit odd with regular steps between 14.6 & 15.2V, was it connected to a charger at the time?  

[Cam_the_comie]

Not saved, will need to run engine again to capture it. As for the battery voltage that was the cooling fan kicking in and alternator ramping up.

[Cam_the_comie]

Scope capture as requested.

TRIG - Run Cold just after start up.llgx TRIG - Run Hot Stalling.llgx TRIG - Run Warm Okay.llgx TRIG - Hot and trying to start.llgx

[Adamw]

It looks like either the new hall sensor is not interpreting the window width well, or the window width on the chopper wheel is wrong.  The narrow tooth is wider than it should be, making it difficult for the ecu to distinguish it from the normal teeth.  

The rising edges should be 90deg apart.  The narrow tooth should be 35% duty or 31deg wide.  the normal teeth should be 50% duty or 45deg wide.  

Your narrow tooth is stretched out to about 38deg wide so with a bit of uneven cranking speed etc the ecu cant see a tooth that meets the criteria for the narrow tooth.  You can see the trig 1 state at the top is staying at "test narrow tooth" 

It looks like it is actually mostly the rising edge of the narrow tooth that is wrong, you can see in the pic below the 180/360/540 marks all occur slightly earlier that the rising edges on the wide teeth.  That would mean cyl 1 is probably getting a bit more advance that the rest too.  You could possibly try trimming a bit off that narrow tooth.  We could possibly adjust the code to accept less variation between teeth but when the narrow tooth is 38deg wide and the wide tooth is 45deg wide there is not much room for speed variation etc.  

In the "Run cold just after start" scope the narrow tooth is 35/36deg wide so there may be some heat related sensor variation.

 

 

 

[Cam_the_comie]

Some feed back on this. We removed the chopper wheel, carefully measured it and found exactly as descried above. We then machined the narrow tooth rising edge side. Once assembled the engine has been running fine as the temperature rises. The rest of the truck is still being reassembled so are yet to road test but are quietly confident it should be fine.