civicservice

I'm having a very hard time getting non-zero fuel pressure readings with my 99 Civic DX. One kit I've seen recommended is this one:

Best Fuel Pump Diagnostic Kit Parts for Cars, Trucks & SUVs

It has all of the hardware needed, including a Schrader adapter to fit on top of the fuel filter banjo bolt. I can get it hooked up without issue by following the directions.

I used a kit like this to measure pressure, and it was in spec. But after releasing pressure with the gauge button and trying again, the reading was zero. I've tried four different units and I either see zero immediately or zero after the first reading.

This may not be relevant, but the last time I tried, I left the banjo bolt adapter free, then primed my fuel pump. Fuel shot out like a geyser. It seems like fuel should only escape when the Schrader valve button is pressed, or am I missing something?

Can anyone point me to a reliable kit and method to measure fuel pressure on my Civic?

CX-Adam

I've a gauge that sits directly on the fuel filter and stays there. It works fine.

You're re-priming the pump, right? The gauge will naturally drop to zero when you release the pressure but, it should jump back up when you re-prime the pump. The fuel pressure will be lower if the car is idling.

civicservice

Yes, I re-prime the pump between readings and get a reading of zero.

mk378

For a quick check on no-starts, I disconnect the return line between the regulator and the pipe on the firewall leading back to the tank. Fuel flowing there proves that the pump is making enough pressure to open the regulator, which assuming the regulator is OK (they seldom fail), means the pressure in the rail is proper. Also the fuel is coming out of the end of a hose in a controlled manner, so you can collect it, check if contaminated, and pour it back into the tank.

Just opening the fitting at the filter and letting fuel squirt out, as shown in countless Youtube videos, doesn't really prove anything. You could only have 5 psi and still get an impressive gush of fuel.

civicservice

To be clear, I'm not suggesting that as a diagnostic technique. It's just an unexpected observation that may or may not be relevant to helping me troubleshoot the problem I'm having with fuel pressure gauges.

Also, quick no start diagnoses are well and good, but I'm really after a way to get accurate and reproducible fuel pressure readings. I'm especially interested in hearing from those who have done this themselves on a 96-00 Civic and the model # of the kit they use.

CX-Adam

B&M 46054 Fuel Pressure Gauge Set