My fuel pump only pumps in the "cranking" position, is that correct?
I'm an off-roader -- XR400R -- getting old, but bulletproof and lots of fun.
Fuel pump circuits are wired differently from truck-to-truck, but the basics almost always hold true.
Turn the key on and the ECM will run the pump for 2 seconds to prime the system (then shuts off). The pump will run continuously while cranking, and once the ECM sees an RPM signal (the engine running) it will keep the pump on until the engine shuts off.
Voltage and ground to the pump while cranking, but the pump does not run, means you need a pump.
Missing voltage or ground to the pump while cranking, means there's a circuit problem which needs to be investigated further.
Thanks for the info!
43 yo "x" mxer raced 125's for eight years, got on the 250's and they bout killed me, I give!
I did my third head set on my Toyota about three months ago, 285,000 miles on it. While I was waiting for the heads to be rebuilt I took the Alternator power lead off to clean. After reassembly the alternator had a dead short, test light was on when poking at the case, Oops, think I might have fried the ECU. Alternator smoked some kinda bad, A few years back I bypassed the fusible link at the main fuse block in the engine compartment. Reckon I'll try a new ECU!
I live 30min. from the Outer banks of NC, It has been a great beach ride since 1992.
Thanks again, Mike
PS Keep your feet on the pegs
You know we don't believe in just swapping parts.
Keep in mind that you should be testing all circuits before replacing anything.
Your old Toyota is a little different than most. There's a main relay, a circuit opening relay (fuel pump) and an air flow meter which applies the relay when sufficient air flow (RPM) is present. (see schematic).
You should start at the pump and work your way back with a test light.
And bypassing a fusible link is a little scary -- that's how fires start.
Oh, Mike, sounds like you've had lots-a-fun in the dirt. I'm a little older, but can't stop riding. It's addictive.
Me and my buddies do the trails out of Steam Boat Springs, CO -- rocks like you wouldn't believe.
Took the CRF250 and 450 out a couple of years ago. That 250 4-stroke can really climb mountains.