Fuel Pressure Problems

[livelyjay]

This is a CA16DE engine on a 1987 Nissan Pulsar SE, just FYI.

I'm still having issues with the car bogging down at low RPMs. I measured the fuel pressure and I'm reading 25psi at idle and 32psi when you pull the vacuum line from the FPR. This is low according to the manual and I should be seeing 28/36. So I ordered a new pressure regulator like the manual says. Well, I got the part, it looks nothing like the OEM regulator, and it doesn't look like you can remove the factory regulator. It has a bracket with two bolts and a hard line into the fuel rail.

Is the factory regulator replaceable? If so, how do you do it and what do you do it with?

[boost_boy]

This is a CA16DE engine on a 1987 Nissan Pulsar SE, just FYI.

I'm still having issues with the car bogging down at low RPMs. I measured the fuel pressure and I'm reading 25psi at idle and 32psi when you pull the vacuum line from the FPR. This is low according to the manual and I should be seeing 28/36. So I ordered a new pressure regulator like the manual says. Well, I got the part, it looks nothing like the OEM regulator, and it doesn't look like you can remove the factory regulator. It has a bracket with two bolts and a hard line into the fuel rail.

Is the factory regulator replaceable? If so, how do you do it and what do you do it with?

Not the same as the DET versions, but I see no reason why it shouldn't be removeable.

[livelyjay]

Since the car's in the garage, I'll snap some pictures and try to take it off either tonight or tomorrow, but the OEM regulator is not the same as the parts being sold by RockAuto or local stores.

Dee, beyond the regulator, do you think the fuel pump might be the issue? That's my next step in the troubleshooting.

[boost_boy]

Since the car's in the garage, I'll snap some pictures and try to take it off either tonight or tomorrow, but the OEM regulator is not the same as the parts being sold by RockAuto or local stores.

Dee, beyond the regulator, do you think the fuel pump might be the issue? That's my next step in the troubleshooting.

If you've never changed the uel pump before, it could very well be an issue. I highly doubt it's your regulator as the stock one rarely fails; especially on the DEs. Also, have you ever changed your fuel filter? And becareful with RockAuto and the pulsar as they usually send the wrong part and I know this because I've experienced it already dealing with them.

[livelyjay]

I know what you mean about RockAuto, which is why most of the time I do a lot of research and looking around before I order. This time, since all the parts pictured were the same, I just ordered it. None of them match the OEM regulator. One of the guys on the EXA forum said the DE has a fixed FPR which can't be removed because it's hard-lined into the fuel rail.

I have never changed the fuel pump, and my guess is the on in there is the original. Which Walbro should I order, the 255lph or the 190lph?

[deuce4Oh]

go with the 255.I have never had an issue with any of them and itwill still be able to flow enough fuel for upgrades. SB: boost shoot me an email or something. I can't PM you

[livelyjay]

So, got some voltage readings at the pump.

Harness side of wiring
Top of plug, where the clip is
1 2 3
X 4 5

Ignition on for 5 seconds, pump sees 11.75 volts for 5 seconds off of pin 3.
After 5 seconds, pump sees .85 volts on pin 2, 8 volts on pin 4.
Pins 1 and 3 on the pump side harness have continuity.

This sound about right?