Hi, I'm having problems with the fuel pump ecu. Firstly I'm not great with electronics so sorry if something I say doesn't make sense :).

The car was having trouble starting, wouldn't kick in until the throttle was pressed down and then it would catch. Plus some time back there had been a smell of hot wiring which went away. I decided to have a look at the ecu and found it running hot. Long story short there was a diode, d5 on the pcb running at 130C. Plus some of the mosfets looked a bit scorched. I took them out and tested them as best I could using youtube and found 1 okay, 1 seemed off all the time and 2 on all the time. I have bought a second hand ecu and I'm waiting for it to come in but I'm nervous about sticking it in in case the same thing happens again. On some of the US sites it's claimed that this can be caused by a dodgy fuel pump? I'd be very grateful for any info or insights that might enlighten me!!! Thanks.

Not come across that particular issue before but the ecu does not drive the fuel pump directly anyhow it signals the fuel pump ecu in the passeneger side rear side panel which has its own power supply as does the fuel pump via the green fuel pump relay in drivers kick panel so cannot see how a faulty pump could overload the ecu. 

The starting issue could be caused by lots of things, bad timing, throttle balance, air leaks, spark plugs , idle control actuator engine temp sensor  or just bad connections.

The ecu heating up maybe connected but mostly even direct shorts at the various sensors will not cause the ecu any issues, maybe just gone bad with age.

 

 

Bypass the FPCU to fix it temporarily by splicing half a foot of wire into the white wire of the FPCU plug and grounding it against a door sill screw. If you upgrade the pump preferably to a silent running one like a deatschwerks DW300 or similar along with a bigger fuel regulator (aeromotive or tomei type L) you can make it a permanent mod and never have to worry about it failing again