2000 Pathfinder runs rough when started

[cminor9]

The ignition coil is inside the distributor. I figured this out via process of elimination. This car doesn't have coil packs, it has a distributor. And there is no center plug on the dist cap which would typically go to a coil. And I didn't see a coil anywhere under the hood. But someone on this thread insisted that the thing has a coil. It makes sense, since something needs to generate the big spark. So I took apart the distributor and found it. Its in there. Supposedly, you aren't really supposed to replace it because the whole distributor is one unit. Which is why you won't find that coil at NAPA or Carquest. Hogwash, says I. ebay to the rescue. It was like $35.

However... after I replaced the coil, the problem cropped up again a few days later. I kinda felt foolish replying to myself again and again, so I never came back with a follow up but I got an email since I am still watching the thread here. So here's the follow up: the actual problem was the fuel pump.

Here is how I diagnosed it (something the idiot dealership mechanic couldn't do, in your face beeyotches): The car wouldn't start one night, and since I had replaced all kinds of electrical components, and the car just sounded like it wasn't getting any gas, something just told me to have a friend turn the key while I pinched the fuel lines (under the hood). I didn't feel pressure like I thought I should have (not sure how much PSI is in those lines, but expected to feel at least ~30 psi). I just so happen to have another friend with a 99.5 pathfinder, mechanically identical to mine, so the next day I had him start his while I felt the fuel lines to get a baseline of what they should feel like. The pressure in my lines was nearly nonexistent. His had plenty of pressure. I have fairly strong hands (guitar player) and I couldn't totally pinch it closed on his. On mine, I could. Uh-oh.

You can get a fuel pump assembly at Courtesy Parts for about $250. I went to napa, got a bosch oem fuel pump, a new screen (important), some small hose clamps (you'll thank me later, since the factory pump has a crimped clamp you'll need to destroy to remove..if you don't have any on hand and you have no other car, you're up a creek). In all, it ran me about $120. I just reused the plastic casing around the pump and the lines and everything.

Took me about three hours. Worst part was getting the fuel pump assembly out of the plastic well it sits inside. This is in the fuel tank, and this part was actually pretty frustrating. You can't really see how it's attached, you are working through a six inch hole with a sharp ridge, and you are inhaling gasoline vapor. Also, you need to be careful so that you don't damage the attached float as you wrangle with freeing the pump assembly from the well. I wish I had run the car's gas down a bit more before doing this. It can't be good for you to work with your hands submerged in gasoline for 30 minutes. On the flip side, some guys have told me it's safer to work on a tank full of gas since there's less vapor. I don't know...once you open the tank there is fuel vapor everywhere anyway.

One more gotcha: when you take the fuel screen off the pump, it might be held on by a spring steel retainer clip. You'll need to save that to get the screen onto the new pump. It was a royal pain to get on and off. After 15 minutes with a pair of needle nose pliers, I worked it back on there. I found yelling at it helps. The price you pay for not paying for the $250 full assembly. Money or convenience, you decide.

I don't say that to scare you, overall it was a pretty simple job. Just trying to share the bits of info the Haynes manual didn't cover. As painful as this pathfinder has been to work on in general, the fuel pump was actually not bad since someone had the foresight to put an access door under the back seat. Somewhere, there is a Nissan engineer for whom I'd like to buy a beer because I didn't have to drop the fuel tank. On the other hand, this job was enough of a pain that I don't want to do it again. So don't get the cheapest autozone fuel pump you can find, and make sure you replace the fuel screen. Also make sure you take the time to get it back into the well again, which is just as frustrating as getting it out. Again, the idea is to make sure you never have to do this again (assuming the pump you got isn't DOA).

Again, the thing has been running perfectly for about two or three months now. Problem solved. May your problem be resolved that easily (well, sorta easily at least).

Hope that helps.

[ARKQX33V6]

I am glad you got it resolved!

[egg998]

how did you change out just the ignition coil?
did you have to remove the distributor to do this?

[egg998]

I didn't feel pressure like I thought I should have (not sure how much PSI is in those lines, but expected to feel at least ~30 psi). I just so happen to have another friend with a 99.5 pathfinder, mechanically identical to mine, so the next day I had him start his while I felt the fuel lines to get a baseline of what they should feel like. The pressure in my lines was nearly nonexistent. His had plenty of pressure. I have fairly strong hands (guitar player) and I couldn't totally pinch it closed on his. On mine, I could. Uh-oh.

I pinched the fuel lines under the hood while the car was running.. i could definitely pinch them pretty easily.. it was definitely easier to pinch than my mountain bike tire at 40psi.. maybe i'll just do the fuel pump.. what are their expected life spans? Thanks cminor9

[cminor9]

did not have to remove distributor to get to the coil, just pulled the cap, rotor, and a few more pieces. The coil was right under there. It'll take you 15 minutes *if* you have a hard time getting to the screw that holds the rotor in place.

I have owned many cars, and I drive em till they fall apart. This might be first fuel pump I have ever replaced, maybe the second. I think it's one of those things, they work till they quit.

I don't really know of a way to test for intermittent failure like I had. You can perform voltage tests but it seems that these would detect an all-out failure. It's a little harder when most of the time it's working fine. It was process of elimination for me. If you haven't done easy things like plugs, wires, cap, rotor, fuel pump, etc, then you might wanna try those first. Certainly much easier and cheaper, and since these are wear parts you are just going to have to do them anyway.

[AZhitman]

Bad cats aren't going to do anything...mine are gone and the car runs fine.

Incorrect. Just because yours are "gone" doesn't mean anything - Cats can fail in different ways, a plugged converter can play havoc with drivability.

Carbon flush, LOL. Scamola.

Also: Not necessarily.

Problems under load at idle (shifting transmission to D) sounds like IACV...

Would have been my first guess. Glad to hear it's resolved!