wczimmerman

Here is my problem:

Recently, when I go to start my 95 GXE, the engine cranks longer than usual. After reading through all of the other posts on this issue, I saw that one diagnostic test is to turn the key on and wait a few seconds, like a diesel engine, before starting. This seems to work consistently to get the engine started in the normal number of cranks. This problem shows up anytime I have to start the car-whether it has been sitting for a few hours, or overnight. The only time it does not do this is if I turn it off for the length of time it takes to fill it up.

I see that it may be a problem with either the fuel pump or a leaky injector, but what are some symptoms of these issues? Once started, the engine runs like a top, and pulls strong. It would seem to me that if there was a problem with one or the other, then it would affect driveability as well.

One other thing-if I start it without waiting, and let it catch eventually, it stumbles a bit. To be specific, it starts to catch, the RPMS go to about 200-300 for maybe 1 second, then it dies. I understand that diagnosing a problem like this is difficult, but I am looking for a direction of repair, and other owners experiences here.

Daniel, you mentioned a fuel pressure test on some of your other posts, but how do I put a gauge on there? Where do I put this "T" connector on the fuel line? How does Nissan test the fuel pressure?

Thanks for your help

Daniel B. Martin

A fuel pressure test is a standard diagnostic test. You will find instructions and a diagram or picture in the Chilton repair manual (page 5-3) and the Haynes repair manual (page 4-3,4). The same test is shown in the Maxima factory service manual.

Bleed the fuel rail pressure by pulling the fuel pump fuse (#32, 15 amps) and making several attempts to start the engine (it won't start). Install a T-fitting with a pressure gauge in the flexible rubber fuel line just downstream of the fuel filter. Install the fuel pump fuse. Start the engine. With the engine idling you should see the pressure maintain a stable 34 psi. Temporarily remove the vacuum signal hose from the fuel pressure regulator. The fuel pressure should increase to 43 psi. Reconnect the vacuum signal hose and operate the throttle to vary the engine speed between idle and 3000 rpm. The fuel pressure should vary between 34 and 43 psi.

Readings less than 34 psi could be caused by an obstructed fuel filter, a weak fuel pump, or a bad fuel pressure regulator. Readings greater than 43 psi could be caused by a bad fuel pressure regulator or an obstructed fuel return line.

After turning the engine off the fuel system should hold pressure for many hours. If the residual pressure bleeds off in only one hour that is a sign of a problem... bad fuel pump check valve, injectors with an internal leak, bad fuel pressure regulator, or an external fuel leak.

Your report of symptoms suggests that a leaking fuel pump check valve is the most likely cause.

wczimmerman

Hmmm....I hadn't thought of that. Where is the fuel pump check valve? What is the difficulty rating in replacing it?

Chris Zimmerman

Daniel B. Martin

It is part of the fuel pump. To replace the valve you replace the pump. However, that is an expensive part. If it were my car, I would "just live with it".

Fuel pump replacement may be done by the intermediate home mechanic. No special tools are required. This service procedure is covered in the Chilton repair manual (page 5-2) and the Haynes repair manual (page 4-4).

wczimmerman

Therein lies the rub: My wife drives the Maxima more than I do, so a special procedure for starting will not do. As for the replacement pump, the cost of the pump for me from the local auto parts place is about $150, but my extended warranty has a deductible of $100. The service through the warranty stinks, but it saves me $50. I may do it myself anyway just to avoid the hassle, though.

Thank you for your help, Daniel. You are a true asset to this forum

Chris Zimmerman