'95 Nissan Pathfinder XE shuts off while driving

[AutoPenalti]

As the title suggests, my father owns a '95 Pathfinder with almost 290,000 miles (bought at 400 miles). He replaced the engine and transmission at 180,000 miles. So it's almost like brand new.

Anyway to make the long story short. My father has been having issues where his car shuts off when he is driving. He almost got into an accident already because of this, and we don't see our mechanic until tomorrow morning. He went to some random mechanic shop and they told us it could be the iginition coils, he replaced them and he left. After about 5 minutes, his car shuts off again driving down the main road. I, then, figured it could be the fuel filter, he went to a mechanic that he trusted and has know for a while. He replaced the fuel filter and checked if anything else seemed off. Nothing was wrong, all the cables were fine, no problem whatsoever. So, as soon as he left, he encountered the same problem again. The engine would shutoff and then he would turn it on and it would start working again. This happened almost 6 times before finally coming home. (We only live 15 mins from the shop)

Finally, My father went back and I tagged along and told him that it happened again driving home. He mentioned that it could be the fuel pump/fuel line that may be about to go out.

Now my question is, what else could cause the engine to shut off like that while driving? It's been happening since last week and I have no idea what else it could be, the car starts up fine, but it's at random moments where it just shuts off, and it's obviously dangerous because he could get into an accident because of this. Any suggestions?

[Blindaviator]

No check engine light or codes?

Try starting it up and let it sit to idle... Make sure to leave the hood closed and the A/C on (if you normally use it when the problem occurs)... If it shuts down while idling I would say it is temp related... Something overheating and shutting it down...

If it stays running it is more likely a loose wire / short somewhere or possibly related to the stress of driving... Driving causes more stress on the fuel pump which could cause it to overheat and shut down... Might also put a fuel pressure tester on it and see what the pressure is like...

When is the last time you filled the fuel tank up?
Most manufacturers recommend you fill the tank at least once a week. Most in-tank fuel pumps have a small cup around them that is designed to hold fuel to act as a coolant for the pump. Over time the fuel evaporates and the pump will heat up causing it to fail faster.

[AutoPenalti]

No check engine light or codes?

Try starting it up and let it sit to idle... Make sure to leave the hood closed and the A/C on (if you normally use it when the problem occurs)... If it shuts down while idling I would say it is temp related... Something overheating and shutting it down...

If it stays running it is more likely a loose wire / short somewhere or possibly related to the stress of driving... Driving causes more stress on the fuel pump which could cause it to overheat and shut down... Might also put a fuel pressure tester on it and see what the pressure is like...

When is the last time you filled the fuel tank up?
Most manufacturers recommend you fill the tank at least once a week. Most in-tank fuel pumps have a small cup around them that is designed to hold fuel to act as a coolant for the pump. Over time the fuel evaporates and the pump will heat up causing it to fail faster.

We actually did have a check engine light when this was occurring but the car was shaking almost to the point of stalling, we changed the fuel filter and the light went away. Before that though, the car would randomly rev up to 4k and then back down and then rev up again at random intervals. We assumed that the fuel needle was not calibrated correctly and we probably had less fuel than what it was showing, so we filled it up with $20 and it seemed to have went away afterwards. After a couple of minutes it occurred again. It was fixed with the fuel filter replacement. The issue of the car turning off again occurred again. So we assumed it could have been the ignition coil. We changed it and that didn't seem to be the issue either. So we are now assuming it could be the fuel pump, but my father wants to know where the fuel pump lies in the car and where to access it, and also if there could be any other issues.

I would also like to mention that this pathfinder has no reverse and the A/C cools for only a couple of minutes and then it heats up (the fan activates). The car also has a ticking noise when accelerating during cold start, we thought it was the lifters, but it may be the exhaust.

[PathyPop]

If you have a CEL you should get a basic $30 code reader to pinpoint your problem, at least you'll have a chance of saving some money. That seems irresponsible for a mechanic to just replace all your coils. Doubtful that could be the problem and expensive. Mine is a 2003 with the 3.5, so a little different, but I had experience with the cam position sensor turning off the engine. If the CPS sensor was disconnected while running the engine would turn off, not sputter, but would completely shut down. Then it would start right up again even with the sensor disconnected and keep running just fine. Just clearing the code with engine running would immediately shut down the engine in the same way. It would always start again with the CPS disconnected, taking a few seconds of cranking. This tells me an intermittent CPS sensor could cause the shutdown you are experiencing. These are cheap and easy to replace, one each on each bank at the top front of the engine.

The reason I found out about the CPS causing this problem is because I had another code for the VVT that caused the engine to go into limp mode. Disconnecting the CPS would give me a different code that wouldn't cause limp mode but would cause the engine to stop as noted.

[AutoPenalti]

If you have a CEL you should get a basic $30 code reader to pinpoint your problem, at least you'll have a chance of saving some money. That seems irresponsible for a mechanic to just replace all your coils. Doubtful that could be the problem and expensive. Mine is a 2003 with the 3.5, so a little different, but I had experience with the cam position sensor turning off the engine. If the CPS sensor was disconnected while running the engine would turn off, not sputter, but would completely shut down. Then it would start right up again even with the sensor disconnected and keep running just fine. Just clearing the code with engine running would immediately shut down the engine in the same way. It would always start again with the CPS disconnected, taking a few seconds of cranking. This tells me an intermittent CPS sensor could cause the shutdown you are experiencing. These are cheap and easy to replace, one each on each bank at the top front of the engine.

The reason I found out about the CPS causing this problem is because I had another code for the VVT that caused the engine to go into limp mode. Disconnecting the CPS would give me a different code that wouldn't cause limp mode but would cause the engine to stop as noted.

The CEL went away after the fuel filter replacement so if I end up buying a code reader wouldn't it read as nothing was wrong with the engine, when clearly there is?

[PathyPop]

Not necessarily. For my P0021 code (VVT over advanced), it would go into limp mode way before the light came on. The code would show "pending" on the reader before the computer would indicate the CEL. I think some codes need to repeat a certain number of times before the CEL. I'm more of a leaner than a teacher on this stuff, but having a basic code reader can/has saved much money. In fact I just ordered an Autel519 reader/scanner to be able to better monitor the computer and emissions status.

[AutoPenalti]

I'll order one through Amazon, considering his car is roughly as old as I am, thanks for that tip. I would also like to know where the fuel line can be accessed as well as the fuel pump. He wants to replace it as the mechanic believes that could be another issue.

[PathyPop]

I just got my AL519 scanner today from Amazon for $100. I got this model because it shows emissions readiness. I already tested it, nice feature. Because I recently cleared the codes it is showing a red "X" for the cats not ready, but the smog test allows one "X" so I could do the test today. Still, after a little more driving, it should go green too. Hope this makes sense. This feature alone is worth the money.

I looked into the fuel pump too because our sending unit is flaky. Very easy to get to if yours is the same as my 2003. There is an access panel under the left passenger seat, under the carpet. I think an after market fuel pump is only about $50 too.

[AutoPenalti]

Well, I'm hoping it's easy as yours because, one way or another, we need to find out what the issue is before this becomes something much more serious and god forbid fatal. It doesn't show in the pathfinder manual which is odd.

[AutoPenalti]

It looks like the distributor and something else inside it. The speed sensor is also an issue. The hose that's near the air filter needs to be changed. Looks like it's cracked.

[Blindaviator]

If you have a CEL you should get a basic $30 code reader to pinpoint your problem, at least you'll have a chance of saving some money.

One small problem... OBD2 started in 96 and this is a 95... It likely has OBD1 which will have VERY limited diagnostics associated with it...

[PathyPop]

One small problem... OBD2 started in 96 and this is a 95... It likely has OBD1 which will have VERY limited diagnostics associated with it...

I did not catch that. Was thinking it was an early R50. It doesn't even have a CPS (but does have a crankshaft sensor). At least the fuel tank has an access panel under the carpet.

AutoP - sorry, your model is the one before mine.