fuel injection over fueling?

V8 sprite · Post by **V8 sprite** » Fri Jun 06, 2014 9:40 pm

Evening guys
I have been putting together my v8 sprite for a few years now and have got around to trying to start it. Firstly there was no spark so i had to get a new distributor and coil, now i have spark and it tried to fire but the fuel ended up flooding into the bores and when i took out the spark plugs petrol ran out of 5 of them.
I have a fuel pressure gauge in the line and it raised upto about 26lb and then immediately dropped when turning over

I then disconnected the injector wires and turned on the ignition, fuel pumps came on and pressurised the rail the pressure stayed up and only dropped very slowly.

My thinking is the ecu is keeping the injectors open all of the time and that is causing the over fueling.

Is my ECU knackered or is it something else
I have a 14CUX AMR3242

Your thoughts would be much appreciated
Dave

Post by **katanaman** » Fri Jun 06, 2014 11:18 pm

get an LED and put it on an injector connector. If it stays lit something is wrong if it flashes then the ECU is switching. A scope would be even better if you have access to one. Another option might be a stick/screwdriver to your ear from an injector or a stethoscope. You should be able to hear it click.

Eliot · Post by **Eliot** » Sat Jun 07, 2014 8:11 am

Suggest you keep a VERY careful eye on your oil. A lot of the fuel will find its way into the sump, thinning the oil out - resulting in knackered bearings.

DaveEFI · Post by **DaveEFI** » Sat Jun 07, 2014 8:44 am

There are two injector driver circuits and they'd both need to be faulty to inject fuel continuously. My guess is it isn't firing correctly and when cold quite a bit of fuel will be injected. Are you certain the timing is correct? A timing light should work when cranking.

Also find out why the fuel pressure is wrong. It should be nearer 40 before the engine starts and drop to about 30 with it running.

V8 sprite · Post by **V8 sprite** » Sat Jun 28, 2014 4:59 pm

Thanks for your help guys I have drained the very thinned out oil and changed the ecu. Fuel pressure went upto about 40lb and it fired up, unfortunately on revving it's picked up a bottom end knock.
Oh well it will keep me busy
Thanks again
Dave

Eliot · Post by **Eliot** » Sat Jun 28, 2014 10:16 pm

Sounds like you didnt catch the bad oil in time.

had a 440 mopar that had been endlessly cranked on a carb that was flooding into the engine.