97 QX4-No Start

[cali4rnr]

Hey everybody-I've been a lurker around here, trying to solve the problems my mom has been having with her 97 QX4.

Let me set the stage:For a few months my mom's been having trouble with her 97 Infiniti QX4 not starting when hot; yet, if it's left alone for ~30 minutes or so, it'll start right back up. Most recentely, it's been stalling after sitting at idle for ~10 minutes while warming up in the morning. The stalling happens much more often than the no-start scenerio.

This is the work a couple shops, myself, and a Nissan dealer have done. Keep in mind that my mother lives in rural Wyoming and there's no Infiniti dealer within 6 hours of her home; thus, we had to take it 3 hours away to Billings, MT to find a Nissan dealer that would touch it.

-Fuel pump & sender replaced (pressure ok).-Distrubitor & cam sensor replaced. ($$$)-Timing belt replaced (maint. schedule)-problems existed both before and after replacement.-TPS Replaced-Coolant temp sensor replaced-EFI/Fuel Pump Relay Replaced-Fuel pressure regulator tested & ok-Plugs & wires replaced-Ignition switch replaced (why???)-It had a CEL for the MAF sensor. I cleaned it, still came up. MAF Replaced. No more code, yet the vehicle still has the same symptoms.

It has spark, & and it has adequate fuel. The plugs look perfect.

After the MAF was replaced, and the symptoms were still evident, we drove it back up to MT and left it for 4 days. No code, no problem..dealer can't duplicate problem.

All of these parts/labor charges have totaled over $3000, and IMO are needless. For this price, she could have dropped in a used, running engine with all the associated sensors installed, and had a good working vehicle.

Any ideas from you guys here? I'm about 1500 miles from the vehicle, but I'm open to any and all suggestions that may help get her back on the road.

[NISTECH]

With the vehicle running wiggle the harness tie wrapped to the intake boot between the air filter and throttle body. There is a known incident with the maf harness where it is tie wrapped to the boot. This usually cause the car to stall.

[cali4rnr]

With the vehicle running wiggle the harness tie wrapped to the intake boot between the air filter and throttle body. There is a known incident with the maf harness where it is tie wrapped to the boot. This usually cause the car to stall.

Thanks, I'll have to give that a go. What's the solution to this problem?

[NISTECH]

undo the tie wrap a bit so it is not being pulled so tightly from the maf when the engine torqs

[cali4rnr]

undo the tie wrap a bit so it is not being pulled so tightly from the maf when the engine torqs

Checked that wire bundle, and it doesn't seem to be too tight at all. Nontheless, it got loosed it up a bit. Still have the same symptoms.

Lame.

[NISTECH]

When it wont start. Does the engine crank but not fire or does the engine not crank at all? This would lead me to think starter if its not cranking at all. Giving it a wack while holding the key in the start position usually gets it to start turning the engine.

If it cranks but doesnt fire up you need to find out what the engine isnt getting at the moment of failure,fuel or spark. I know your some distance from the vehicle but this sounds like a complex issue that will require at a minimum a fuel pressure gauge for accurate fuel pressure readings, and a noid light to check injector pulse at the moment of failure.

You should probably make sure your engine control harness grounds are clean and secure on the intake plentium. They are located either at the front of the plentium right next to the distributor or on the middle of the intake along the harness. may need to loosen them clean them with a wire brush and resecure them.

[cali4rnr]

When it wont start. Does the engine crank but not fire or does the engine not crank at all? This would lead me to think starter if its not cranking at all. Giving it a wack while holding the key in the start position usually gets it to start turning the engine.

If it cranks but doesnt fire up you need to find out what the engine isnt getting at the moment of failure,fuel or spark. I know your some distance from the vehicle but this sounds like a complex issue that will require at a minimum a fuel pressure gauge for accurate fuel pressure readings, and a noid light to check injector pulse at the moment of failure.

You should probably make sure your engine control harness grounds are clean and secure on the intake plentium. They are located either at the front of the plentium right next to the distributor or on the middle of the intake along the harness. may need to loosen them clean them with a wire brush and resecure them.

Thanks again-When the "no start" condition occcurs, the engine cranks just fine and without issue. The starter is relatively new.

The fuel pump, and the fuel pressure regulator have been replaced, and the pressure tested. It checks out ok. At last inspection, the engine was getting fuel and spark. Now i'm not sure if a noid light has been used to check the injector pulse, so I'll look into that. Good tip on the ground. I'll have somebody check those, too.

I just got word this morning that it threw a CEL, so I'm shipping off my OBDII reader today so that code can be pulled. Hopefully the CEL will shed some light on a possible problem. I honestly don't know what else could be physically wrong with the car; nearly everything has been replaced, it still has decent power, gets great mileage, etc.. The only thing left that I can think of that could possibly be malfunctioning is the IAC, perhaps.

You see, I personally drive a Toyota 4Runner, and I fee very comfortable working on it. But at this point, I'm by no means a pro mechanic, and I can't help but stab in the dark from 1500 miles away. I'm only going off of what I observed when I tinkered with it last month, and what I'm told daily by phone.

[cali4rnr]

And this is me venting:

These things have a LOT of "known issues"...

Prematue head gasket failure, bad MAF wiring, the worlds laziest AC Compressor.....Ugh.

[NISTECH]

As far as the fuel pressure and spark tests I meant at the time of failure. Like when it wont start. I dont suggest throwing any more parts at it till you or someone diagnosing it actually sees the failure occur. If it cranks and does not start it is not getting one of three things. FuelSparkCompressionIts obvious compression is NOT an issue as it will run. Compression is not something that comes and goes.However not getting fuel can mean a couple different things. Loss of pressure or loss of injection of fuel. Either one can be caused by different problems.Loss of spark can be caused by a multitude of problems.

If this car wont start one of those 3 is not present. Compression is ruled out here.So you need to see which of the other 2 it isnt getting when it wont start.

For the record The pathfinder is not known for premature head gasket failure. I think I have done 2 since the inception of the r50 pathfinder (1996-2004 model)

My boys at Toyota though tell me the 4 runner 3.3 v6 is pretty common for it and actually had a recall on it.

[dcorazal]

Hey did you ever get this resolved?

My 97 Pathfinder is having a similar problem with the hard starting (no stalling though). I starts fine in the morning but if I leave it site for 15 minutes or longer it cranks for a long time before it starts. It seems to help if I press the accelerator while cranking. I'm afraid to start throwing money at is. Any one with experience with this symptom??

[cali4rnr]

No resolution yet. I'm actually in the presence of the car this week, so I'll be poking around it.

It does have a new problem, though. The transmission seems to slip from 0-30mph. You can WOT and it'll only rev to 2.5k, unless you drop it into 2nd.

Looks like it'll be traded in on an 06 4Runner. Soon, very soon.