97 QX4-No Start

[Guest gapguy]

Hey everybody-

I've been a long time lurker around here, trying to solve the problems my mom has been having with her 97 QX4. I found another thread (with video) that seemed to be helpful, but in the end was not.

 

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.

[88pathoffroad]

Mine did that exact same thing when the coil's power transistor died. I am unsure if they use the same setup on the 97 Q's, but it may be worth looking into.

[Guest gapguy]

Bump. Anybody?

[vengeful]

Did you investigate 88's suggestion?

 

I don't have a clue. I'd think the Coil Transistor would be a good place to start.

[Guest gapguy]

Did you investigate 88's suggestion?

 

I don't have a clue. I'd think the Coil Transistor would be a good place to start.

I don't see an entry in the FSM for any sort of Coil _or_ transistor.

[vengeful]

Do you have any Trouble Codes?

[Guest gapguy]

Just had two codes pop up, and pulled them:

P0120

P0325