Where is the Fuel Pressure Regulator?

[eduJ]

I have a 1998 QX4, and I've been trying to locate the fuel pressure regulator on this truck. I've searched images online as well as looked in the "FE" section of the service manual but no luck so far. I was hoping someone can steer me in the right direction here.

My problem: I've been getting periodic long cranks (3-4 seconds). There seems to be no pattern as to when this occurs. I was advised by a member on this forum that it may be a bad fuel pressure regulator. I'd like to check it out--apparently I can take out the vacuum line on it and if it has gas in it then it's bad. Of course, I haven't been able to locate it so I'm not able to check.

Thanks in advance, and happy holidays!

[atraudes]

Sounds like you're on the right track. It's on the back of the engine instead of the front. Check out EM-9. EC-34 and 32 have a slightly different diagram of the fuel rail, too. The FPR will be bolted/screwed onto the end of the fuel rail.

You're right; there's precisely 0 pictures of it online. Shoot and post some pics if you get a chance!

[Leo1998]

It's under the intake manifold at the back of the engine, you can feel a rubber fuel hose coming off of it. Let me know what you find out because mine does the same thing. I think it's a sealed unit and not sure how you can test it without putting a pressure gauge in the line.

In the service manual for mine is a good picture on ec-28 should be the same for yours.

[atraudes]

The quick and dirty way to figure out if it's dead is to smell the vacuum hose going into it. If the vacuum hose smells like gas, it means the internal valve is defective.

The more thorough test is to hook up a fuel pressure gauge to the fuel dampener (other side of the fuel rail), hook up a vacuum pump, start the car and make sure sure the fuel pressure reacts per spec as you use the vacuum pump.

An alternate technique is to just hook up the fuel pressure gauge and see if the pressure is to spec while the engine is running. If it's sticking open like mine was, the fuel pressure will also drop like a rock after the engine is shut off. A good FPR will maintain pressure for quite a while.