1998 Tacoma 2.7 No Fuel

Gents,

I've searched this forum for a while and I think I've narrowed down my no fuel issue but would appreciate any advice.

My 2.7L has no fuel while cranking. I believe the logic to close the Circuit Opening Relay, the ECU has to see "healthy" signals from the Crankshaft and Cam position sensor. In my case I don't think the ECU is getting good signals from one or both. I plugged in my XTOOL X8 scan tool and I can force the signal to close the CO. I can hear it click and assume it's energizing the fuel pump because the next attempt to crank, it will sputter briefly and shut off (because the CO is not staying closed).

So to me, it makes sense to jump the CO and try sending 12v to the pump to confirm it will run. Then try narrowing down which sensor or wire to same is bad. Note; this is currently my farm truck so not worrying about day to day driving, I just need the thing to run at this point.

Thanks!

 

Jump the fuel pump at the under hood diagnostic connector and see if it’s starts and runs normal…that’ll prove the fuel pump hood or bad.

that’s where I would start.

Can you get mode $6 data on your scanner? Can it graph? Look at cam and crank sensors, as well as IGT and IGF signals while cranking or running with the fuel pump jumped.

some of these ECMs of this vintage like to blow out the coil driver transistors…and when the ECM doesn’t get a feedback signal confirming a firing event on 2 consecutive coil triggers, it shuts down the fuel pump via the COR.

 

I think I can graph, but I need to look into it more. I just got the XTool recently and have only used it on my F-150 and the Tacoma briefly.

Can you explain how I can jump from the diagnostic connector? I know the connector you're talking about, but not sure how to do it.

 

It’s been a while and I don’t have access to alldata anymore….but there should be a fP terminal…that’s fuel pump. Then with e1 or tE1 is hot. Jump from the hot to the FP and that should run the pump…or jump direct from battery positive to the fP