Page 1 of 1
M50b30 nv no start
Posted: Tue Dec 11, 2018 9:34 pm
by bimanut
I've built an m50b30 using m54b30 crank,rods,pistons and two nv inlet cams.
The engine ran as a 2.5 when I last started it.
But after I've turned into the stroker it won't fire.
Turn the key
Starter turns
No fuel (flows when relay bridged)
No spark
DME relay clicks but doesn't turn on fuel relay
New crank sensor
Cam sensor reads correct ohms
I tried switching the two sensors over in case I had them plugged in wrong way but no difference still no fuel.
Checked all earths with meter and all are showing good.
I'm not convinced the ecu is dud but i got another one and still no change.I also ran another earth to the casing to ensure a good earth.
I've run out of things to check or try.
The only other thing I can think of is that I've managed to time tdc and cams the wrong way but is that even possible?
Anyone got any other ideas to try?
Re: M50b30 nv no start
Posted: Tue Dec 11, 2018 9:38 pm
by bimanut
bimanut wrote: ↑Tue Dec 11, 2018 9:34 pm
I've built an m50b30 using m54b30 crank,rods,pistons and two nv inlet cams.
The engine ran as a 2.5 when I last started it.
But after I've turned into the stroker it won't fire.
Turn the key
Starter turns
No fuel (flows when relay bridged)
No spark
DME relay clicks but doesn't turn on fuel relay
Both known working relays
New crank sensor
Cam sensor reads correct ohms
I tried switching the two sensors over in case I had them plugged in wrong way but no difference still no fuel.
Checked all earths with meter and all are showing good.
I'm not convinced the ecu is dud but i got another one and still no change.I also ran another earth to the casing to ensure a good earth.
I've run out of things to check or try.
The only other thing I can think of is that I've managed to time tdc and cams the wrong way but is that even possible?
Anyone got any other ideas to try?
Re: M50b30 nv no start
Posted: Wed Dec 12, 2018 9:20 pm
by Brianmoooore
Cams and everything else at the top end may or may not be correct, but will have no bearing on the fuel pump not turning on or you not having sparks, even if those sparks would be at the wrong time.
The only things that are relevant are the crank position sensor, its connection to the ECU, and whether the ECU is powered up correctly.
Any EWS involved in this?
Re: M50b30 nv no start
Posted: Wed Dec 12, 2018 10:20 pm
by bimanut
That was my thinking regarding the top end but having thought about I think they are right, the
front lobes on each cam face inwards towards each other.
Its a new sensor reading 510 ohms
I checked power on ecu
Red/white wire +12v
Earth worked also
No ews,using light green 403 ecu
I know its for an auto but shouldn't make any difference surely.
Auto loom has also been removed which has left 3 cut wires from ecu, black,brown/orange and other brown/?
I have bought a chip claiming to be for this stroker but I thought the 403 would be enough to get it running albeit a bit rough
Re: M50b30 nv no start
Posted: Wed Dec 12, 2018 10:51 pm
by Brianmoooore
That's the non EWS version, as you say, and is fairly unsophisticated as ECUs go. Permanent power and earths to where they should be, ignition live to switch it on and a good crank sensor connected to the correct pins, and you should get sparks and the pump relay switching on as the crank rotates. Nothing else is relevant.