I just installed a fuel pressure gauge to get my pressure readings.
With the engine running warmed up it runs about 33-35 psi with the vacuum hose connected to the regulator. When I take the hose off and plug both ends, pressure goes up to about 38-40 psi.
Sometimes when its hot outside and I drive the fuel psi goes slightly below 30. If I rev it in neutral fuel psi will go up about 4 points then go back down. After a few hours sitting without it running, the fuel psi will go to zero till I turn the key.
Are these readings normal, or do they seem low?
FUEL PRESSURE SPECIFICATIONS
Fuel Pressure [1] (290-340 kPa) 41-48 psi
[1] measured with engine idling and vacuum hose to pressure regulator disconnected and plugged
Fuel Pressure [2] (225-275 kPa) 32-39 psi
[2] measured with engine idling and vacuum hose to pressure regulator connected
copyed from alldata
So with the hose connected the psi is in spec.
Since psi is too low with hose disconnected, is this likely to be
the regulator?
Could it be a leaky fuel injector?
I have followed the fuel pipe and there are no leaks anywhere.
no its just because you lost vacuum. thats perfectly normal.
as far as the pressure drop, Im not 100% sure on this but I believe thats also normal. If its not there are a couple places you could be dropping pressure. the injectors, the FPR or the check valve in the pump and the very unlikely leak in the line of fittings.
overall, everything looks fine to me. Whats your actual problem that has your watching your fuel pressure so closely?
She is starting to get slow, especially in the heat. Also smells like it might be running a tad rich. I have a brand new Honda distributor (AC delco coil, everything else is brand new oem.), timing is correct. New plugs cap rotor wires. New Honda IACV. Also brand new ECT sensor.
I have had a few times where I go to start it and it takes longer than normal to start. But only every so often. Sometimes after it cools down after driving it in the heat. My main relay is perfectly functional. The computer on the inside is clean with no bad solder connections. Sometimes when I start it it starts rough. Like its not getting enough gas.
well you migh thave to adjust your throttle a bit and raise it. just to give an idea im running a b18c itr and in cold starts i idle at 1500, after warm up its at 1k then in midday heat it will drop to 800 then start to loop a bit… im at 45.5 psi in normal temp, i bumped it +5psi from what i thought was stock psi in warmup 43.5psi…
I have already adjusted the throttle on the car. My fast idle and warm idle are in spec.
it could possibly be your fuel pump it is possible to have good pressure with low pumping volume meaning good psi but the fuel pump is not flowing enough fuel. have you ever changed your fuel filter and also do you drop fuel pressure as soon as the car shuts off.
I changed the fuel filter about 2 months ago with a Wix. Made sure the in and out hoses are in the correct place. The old filter had some rust settled on the bottom. As far as fuel pressure dropping, not immediatly after turning off the car. But it goes down about 5 psi immediatly then goes down to zero in about an hour or so.
When the car is running fuel pressure will be around 35 psi then go down a little sometimes. This is when it seems kind of slow in the low RPMs. When I disconnect the hose at the regulator and block the vacuum the pressure never goes over 38 or so.
is there anybody you could swap regulators with to see if the problem improves.
Dont know anyone with one but on rock auto they are only 30 bux so Ill buy one and see what happens.
Ok well today for the first time since installing my radiator I had a little bit of over heating. It only happened when I was entering the freeway. I pressed the gas good for power but it was nothing but slow to 60 mph. But for a brief second, my coolant temp gauge went past the normal mark, but nowhere near the red. About 5 seconds later the temp goes back to normal. After that there was no more climbing coolant temp. Not even stopped at a stop light for 4 minutes.
Is running lean a cause for no power when accelerating and causing brief over heating?
It was 95 degrees out and the car had been running good all day. Sometimes when I start it it would take an extra second as if fuel was not at the injectors.
(Update found out the radiator fan switch was failing intermittently. Thats what caused the over heating.)