okay so i just upgraded my stock FPR on my 7M to a new aftermarket Areomotive fuel pressur regulator and i am just woundering if anyone can tell me the stock fuel pressure it should read on the gauge. thanks
FUel PRessure REgulator
- Thread starter jcr2fast4u
- Start date
^ What he said.
You'll see the FPR explained in various ways but the bottom line is Toyota's stock Type A fuel injection system requires a constant 36 psi differential between injector inlet and outlet. That is, not coincidently, the midpoint of the 33 to 40 spec given in the TSRM when checking fuel pressure with the vacuum hose disconnected or the engine off. It'll be a good place to start.
You'll see the FPR explained in various ways but the bottom line is Toyota's stock Type A fuel injection system requires a constant 36 psi differential between injector inlet and outlet. That is, not coincidently, the midpoint of the 33 to 40 spec given in the TSRM when checking fuel pressure with the vacuum hose disconnected or the engine off. It'll be a good place to start.
Is this the same with a APU set up? I have my car running @38-39, but I am going to get tuned next week. jcr2fast4u ........is your car otherwise stock?
It never explains QUITE clearly in the TSRM, are you supposed to make adjustments for the PSI while the engine is cold or warm?
Doesn't matter if warm or hot because all you're doing is setting baseline fuel pressure. What matters is the regulator port be at atmospheric pressure so as not to be influenced by manifold vacuum. That happens with the engine off or the hose disconnected when it's running.
Now it's true with the engine running and the port at atmosphere the mixture will shift richer (after all the differential is more than 36 psi then) until the O2 sensor brings it back into line but that's not important because you're going to reconnect the hose when finished anyway. Besides, you're only concerned with fuel pressure when doing this, not mixture.
NA engines use the Type B system. The spec for that is 41 psi which, again not coincidently, falls at the midpoint of the TSRM spec of 38 to 44 psi engine or hose off. Keep in mind I'm talking about stock motors here.
Now it's true with the engine running and the port at atmosphere the mixture will shift richer (after all the differential is more than 36 psi then) until the O2 sensor brings it back into line but that's not important because you're going to reconnect the hose when finished anyway. Besides, you're only concerned with fuel pressure when doing this, not mixture.
NA engines use the Type B system. The spec for that is 41 psi which, again not coincidently, falls at the midpoint of the TSRM spec of 38 to 44 psi engine or hose off. Keep in mind I'm talking about stock motors here.