Fuel pressure at 80 psi while running.

Swapped stock b18b1 FPR with stock b18b1 twice.
Checked fuel return line from FPR to drain pipe in tank.
Ran fuel return hose into a fuel can.
Swapped stock d16y8 obd2 fuel injectors with stock b18 obd2.
No contaminants in fuel rail.
The car was broken into and the ignition was damaged and caused the #9 15a and 40a IGN under hood fuse to blow, both replaced.
7 different ecus have been tried, 4 different socketed ecus with 3 separate chips, 2 obd2b ecus and 1 unmodified obd1 P75. No codes.

Prime fuel pump without starting engine, all 3 FPR hold 42 psi.
Start engine, pressure goes up to 80psi.
Shut off engine, pressure falls to 42psi and holds.

I never had an issue with the fuel pressure before swapping the engine and all the sudden its washing fuel down the cylinders and contaminated the oil.
If the fuel pump was somehow receiving too much voltage wouldn't it blow a fuse?

 

 

…..and yet you still think the 25+yr old fuel pump is still working properly

 

This is not a complex system. It is purely mechanical. The pump runs constantly and moves more fuel than the engine can use. When the pressure in the fuel rail reaches the design point, the fuel pressure regulator opens to release the excess fuel into the return line and it goes back to the tank.

The path between the gauge and the regulator must be unobstructed so they see the same pressure. Also it's possible the gauge is wrong. Fuel rail pressure of 80 would be running poorly and making black smoke from the tailpipe. The pressure when the pump is not running isn't very important other than that it should not drop immediately to zero.

 

Have you tried a different gauge? Where are you reading the pressure at, the fuel rail?

Cheap fuel pressure testers never read right.

 

Bad FPR, disconnected or clogged FPR vacuum hose, or clogged return line.

 

Yes because I had no issues with it before I drove the car into the garage and removed the engine. And if it was failing why would it be increasing pressure?
The gauge isn't wrong. The engine does run very poorly in the few seconds I let it because there is so much fuel pressure.
It's a standard pressure gauge from an industrial supplier, not some POS from ebay. The gauge is correct and has been used on another chassis. It's on top of the fuel filter.
Do you even bother to read? 3 good FPR were installed. They all held 42 psi with engine off. The vacuum line is present and unobstructed as is the return line to the tank which I already stated I bypassed completely after checking it anyway.


Nobody has answered the only question I asked in the original post. IF the fuel pump were receiving too much voltage, wouldn't it blow a fuse?

 

Thanks for the helpful post.

 

have you verified that it getting more than what its suppose to receive? have you figured why its getting more volts than it should? is this another 'what if' thread?

 

I don't know if it is getting too much voltage yet because I haven't replaced my multimeter. If this is the case wouldn't it blow a fuse?

There is no question about the fact the pressure is too high and that it is the cause of my issues. The engine won't rev above 5k because it's dumping so much fuel into the cylinders the a/f ratio is too rich to ignite. There are no obstructions at all from the fuel rail to the tank and again I repeat myself when I say I removed the return line and ran it into a fuel can with 3 different FPR that all tested good and have no issues on other vehicles.

 

One or more tests above were either done wrong or misinterpreted.

I know this because you commonly supply incorrect information or misinterpreted results in your threads, dictating the need to ignore your conclusions and to focus on problem symptoms.

Not all questions are worthy of a response. This is one of them.

 

Says the guy who told me the problem was the ECU.

Tested per FSM engine off, prime key twice and check fuel pressure. 42 psi.
Tested per FSM engine running, vacuum line disconnected and pinched. 80psi.
Tested per FSM engine running, vacuum line reconnected. 80 psi.

Inspect fuel return line. Eliminated by visual inspection of entire return line and by completely bypassing return line.
Faulty FPR. Eliminated by replacing with 2 known working from a vehicle with no fuel issues.
Testing FPR per FSM only says that pressure should rise when reconnecting vacuum line. The fuel pressure is already way past OEM spec so it won't rise.

I haven't supplied any incorrect information. It's not my fault you can't understand that a stock Integra ecu must be used in a Civic and it's the only way to legally swap to a B18/B20 in CA per the state BAR. Funny how you had nothing to say about that.

This is also literally the only issue I've made a thread about asking for help. So knock off your BS about 'commonly providing false information and misinterpreted results in your threads'.

Keep the bullshit in GDD. This is a serious issue that I'm trying to solve and if you can't manage to provide input without personal attacks then stay out of my thread.

 

Glad to see you have a sense of humor.

 

Thanks for your input.

 

Key prime twice engine off.
Engine running FPR vacuum disconnected and pinched closed.
Engine running FPR vacuum reconnected.
Engine off.






Changing the injectors seems to have realized an unrelated 10 psi drop off max pressure.

 

check fuel line and fuel for any "contaminates"?

 

Please read the entire first post. Yes.

The same FPR and gauge (without 90° fitting) as the above 4 photos now installed in my Integra.

Key prime twice engine off.
Engine running FPR vacuum disconnected and pinched closed.
Engine running FPR vacuum reconnected.
Engine off.





What do you have to say about my testing methods now @muellersfan?
@TheShodan can you please add your thoughts?

 

 

1. I don't see "up to 80psi"
2. you still haven't proven that your fuel pump is getting more voltage than it should. best get that dmm out.

 

70 psi is close enough to 80 but this was after I removed the fuel rail and swapped injectors.

You still haven't processed the fact that I stated I don't have a multimeter on hand. Muellersfan doesn't seem to think the fuel pump matters.

I can't understand how swapping the engine would cause the pump to all the sudden increase fuel pressure but it's the only part left in the equation.

 

We should abandon idea of high voltage at the fuel pump until you have evidence to support. An adequate multimeter can be purchased from HFT for under $10. When you have it, measure voltage across the two battery posts. Voltage at the fuel pump can't be higher than that.

Is the 70 PSI fuel pressure read with the engine idling? Is the idle speed at spec?

Disconnect the fuel return hose from FPR and place end of hose into a plastic container. Start engine. Is any fuel released into the container? Work in a well ventilated area.

 

I planned to get a multimeter, but this is my daily driver and I'm not going to drive it in this condition.
Yes, all readings are at idle. Increasing the rpm raised fuel pressure to 80psi.
Yes, fuel was released from the return line into the fuel can when engine was running.

 

A question that remains is whether the FPR is releasing enough fuel to drop the pressure.

Maybe I missed it. Did you compare the fuel pressures with the FPR vacuum hose connected versus disconnected at idle?

 

Yes, I posted all the images with a description above.

The first group of images is the FPR installed on the clean fuel rail in the Civic.
The second group of images is the same FPR installed on the fuel rail in my Integra.

Comparing the images you'll see a 4psi drop in the civic with the vacuum line connected at idle.
Then, when installed in the Integra, you'll see a 10 psi drop to normal pressure.

 

Disconnect the fuel return hose in engine bay and place hose end into can as you did previously.

Start engine, read fuel pressure at idle and watch fuel flowing into can.

Does fuel pressure now read normal with fuel flowing into can? If so, return line is clogged between engine bay and gas tank.