G4 extreme no start hot?

[Kassan1973]

Hi all just wanted to know if there were any previous issues with older g4 extreme ecu , i have one in an EB ford with ef crank and cam sensors runs fine but lately when i turn car off and come back to restart it 10 minutes later it cranks no fire , when i connect pc its showing no engine rpm. I have connected a std multi meter and checked the voltage on the crank trigger wire at the ecu and there seems to be some variation during cranking , today during the warmer weather In melbourne i disconnect ecu and left in the shade for 5 minutes as i was in a carpark reconnected and it started and ran perfectly. I am going to put a new crank sensor in to rule this out is there anythink else i can check to confirm ecu may be failing when hot, It has a sticker with a 4 digit number on the back and im unsure if its been repaired before , 

Thanks Dean

[Adamw]

You will really need to get an oscilloscope on it to see why it is not happy with the trigger signal, it could either be a connection that plays up when hot or it could be the sensor output voltage dropping due to the heat.  The first thing you can try is lowering your arming thresholds on both trig 1 & 2.  drop the 0RPM cell right down to 0.2 to see if that helps.   

[Kassan1973]

Thanks Adam,

Tha original settings were the ones your provided i will make that adjustment and see how it goes.  Are those cheap handheld  oscillscopes on ebay useful for testing this kind of stuff.

 

Regards Dean

 

 

[Adamw]

11 hours ago, Kassan1973 said:

Are those cheap handheld  oscillscopes on ebay useful for testing this kind of stuff.

Some are.  I havent owned or used any of the real cheap <$50 ones but have owned or tried a couple of ~$100 ones.  Avoid the cheap Hanteks like 1008, 6022, they are totally useless.  Owon VDS1022 is good.  Picoscope 2204a is good.  I have also used a PoScope Mega50 or mega1? at someone elses shop and that seemed good.