What should EFI fuel pressure be?
- Thread starter abec
- Start date
That's normal. If you block the return line it should go up to 80-90psi. around 38psi while running (any condition) is the spec.
Caleb X1/9
Low Mileage
That's about right for stock but you might need to bump it up a little bit for your setup with the big valve head. I think I set mine to about 42 or 44 which makes it run better with the cam that's in mine. You might try tweaking the air mass meter spring preload a couple notches first and if that doesn't help then you may want to add an adjustable regulator. I did on mine and now I can tweak it a couple pounds with an allen wrench and set it for fuel economy or for power in a couple seconds. It will definitely help if you ever go to a more aggressive cam and want to keep the stock ecu.
Pressure is fine at WOT. The question remains is it enough flow?
Check your filter, even though it is new it could be clogged or backwards.
Check your hoses, renew if needed.
Check pump output, should be ~500ml in 30 seconds.
Check the wiring at the pump, particularly the ground, and the ground connection at the cluster behind the coolant expansion tank. Poor connections labor the pump, and can reduce flow and pump lifespan.
Other wiring to check; if the engine moves a lot at WOT, check to be sure nothing is getting stretched or tugged.
The pickup in the tank could be clogged with scale or other debris.
On another tach :laugh:, check the tach during failure mode. If it is dropping quickly to near zero when it happens, chase ignition gremlins. If it's dropping smoothly and slowly during failure mode, continue chasing fuel gremlins.
I chased a problem on my Zagato that eventually turned out to be the pickup wires, they were nearly disintegrated. Fixing it created another problem, that the pickup gap was too small. The ignition module would everheat and the ignition would fail. This is why I ask about what the tach is showing.
Hope this helps! I know how frustrating this can be.
Check your filter, even though it is new it could be clogged or backwards.
Check your hoses, renew if needed.
Check pump output, should be ~500ml in 30 seconds.
Check the wiring at the pump, particularly the ground, and the ground connection at the cluster behind the coolant expansion tank. Poor connections labor the pump, and can reduce flow and pump lifespan.
Other wiring to check; if the engine moves a lot at WOT, check to be sure nothing is getting stretched or tugged.
The pickup in the tank could be clogged with scale or other debris.
On another tach :laugh:, check the tach during failure mode. If it is dropping quickly to near zero when it happens, chase ignition gremlins. If it's dropping smoothly and slowly during failure mode, continue chasing fuel gremlins.
I chased a problem on my Zagato that eventually turned out to be the pickup wires, they were nearly disintegrated. Fixing it created another problem, that the pickup gap was too small. The ignition module would everheat and the ignition would fail. This is why I ask about what the tach is showing.
Hope this helps! I know how frustrating this can be.