Vee_Que
You've jumped to the big stuff without inspecting the small stuff. Inspect, then replace.
ToomanyVolvos
So true. If I were were doing this as a job my customers wouldn't be returning!
I can remove and replace a cam angle sensor in 5 mins now though.
I was mostly swapping things I had on hand that I had previously done and overlooked the basic like Dissy cap and rotor. I've had them go bad on other cars but never on a 240 or 740. Sourced new ones of those, I'll see if it helps next week.
nickm
If Leads, Rotor, coil?
Don't help
Get a multi meter and a logic probe and then probe the pinouts for the values listed below.
You can remove the rear covers on the ecus for access.
Pinouts for the fuel ECU
ipdown.net/jetronic.info/tiki-index.php?page=LH2.4+Pinouts+and+Diagrams#LH2.4_Connector_pin_out
Pinout for the ignition ECU
ipdown.net/jetronic.info/tiki-index.php?page=LH2.4+Pinouts+and+Diagrams#EZK_Connector_pin_out
Major Ledfoot
Of course, you can get 1-1-1 from the ECMs and the bugger still won't start, why is why VQ's approach is correct.
But if you're not getting 1-1-1 from the original fuel ECM, there is one problem, although it may not be the only problem.
jamesinc
It might just be flooded. I'd in the first instance disconnect the injectors and crank it with throttle open for 20-30 seconds.
ToomanyVolvos
I've concluded that it's definitely a case of severe flooding and poor spark. I'll see how Dissy cap and rotor goes and failing that the suspicious ECU that won't give codes will have to be replaced with a later LH 2.4 turbo unit.
jamesinc
If it's flooded, when you crank it (with injectors disconnected), once it starts to clear out, the engine should actually catch and splutter a few times (in one extreme instance I actually had the engine running smoothly for about 5 seconds on fuel in the bore, but in that case the ECU had failed and the injectors were being held open at 100% duty-cycle)
nickm
Could be the fuel ECU injector transistors.
A Noid light or a 12volt LED on the injector should flash and either confirm your suspicion.
ToomanyVolvos
Success!
Swapped out Dissy cap, rotor, ECU with same number and even the EZK unit - no start.
Hooked up a multimeter to the injector plug and no voltage, should have done that first as the Dissy is a PIA. Opened up the FI / radio suppression relay and watched it working correctly when ignition turned on. Managed to find a reference where you "jump" the two large wires that plug into this relay and then check for voltage at plug / start. The two large wires being RED and GREY. Holding them together gave power to the injector and start! New relay and all good.
Was still convinced it was flooding and oil smelt of fuel, must have been imaging it.
Thanks guys for the insight!