1998 INFINITY QX4 WONT START

[cnaug76]

Hey All,

I have a 1998 Infinity QX4, after being on the highway for over six hours, I pulled into a parking lot, had my vehicle idling, and out of no where, it began idling really , and after trying to give it some gas, it died all together. I tried starting it up right away, however it wouldnt start, got out and checked oil, gas, coolant, etc, and all was good. After that I let it sit for a half hour, and still won't start. Also put in a jerry can of different fuel, and nothing seems to get it started. Any ideas of what this could be? Any info would be greatly appreciated.

Thx

[PapaSmurf2k3]

Sounds like you're going to have to check all the basics. Fuel, spark, compression, timing. Start with fuel (the way it died leads me to believe it was starving for gas).
You can do this by pulling a plug after cranking and seeing if its wet, or key-on and see if you can hear the fuel pump (and maybe pull a fuel line at the fuel rail and check for flow). The other thing you could do would be to spray some starting fluid in the throttle body (with the throttle open) and then trying to start it. If it starts, you know you've got spark and everything else.

[Eikon]

clogged fuel filter? Any idea when that was last replaced?

[Towncivilian]

Clogged fuel filters rarely cause starting issues. They generally manifest themselves as an inability to reach higher RPMs. If it hasn't been replaced in the past two years, it is still a wise idea to replace it though.

[cnaug76]

Sounds like you're going to have to check all the basics. Fuel, spark, compression, timing. Start with fuel (the way it died leads me to believe it was starving for gas).
You can do this by pulling a plug after cranking and seeing if its wet, or key-on and see if you can hear the fuel pump (and maybe pull a fuel line at the fuel rail and check for flow). The other thing you could do would be to spray some starting fluid in the throttle body (with the throttle open) and then trying to start it. If it starts, you know you've got spark and everything else.

Thanks for your comments, greatly appreciated. What I've done so far to try and rectify the problem, I have changed the spark plugs, cap and rotar, cleaned the maf sensor, changed my fuel filter, and fuel pump. It is still doing the same thing. It starts up when it is cold, and only lets me drive to about 2500 - 3000 RPM, and then after about five minutes of driving, it will stall out and will not start back up until I leave it for atleast another hour. Im at a loss to find out what the problem is. By the way, I have 346 K on it.

[cnaug76]

Thanks everyone for all your comments, I am also new to this forum.

[fueler]

346k... miles?????

Is it throwing any codes? Have you scanned it with obd2 scanner?

[cnaug76]

346k... miles?????

Is it throwing any codes? Have you scanned it with obd2 scanner?

346 000 Kilometers, and I hooked it up to the scanner and it gave me the codes P0300/P0325/P0340. One is multiple misfire, the other is crank shaft position sensor, and I cannot recall what the other is.

[PapaSmurf2k3]

Almost sounds like a coolant temp sensor to me.
A bad Crankshaft position sensor will definitely cause some pretty horrible issues. Its possible the sensor just starts reading all incorrectly once it has warmed up.

[cnaug76]

I just found out what the other code is and it is a knock sensor code. What can I do to check to see if this is the problem? Ive already put in a bunch of money, and don't really want to keep putting more money into it just to find out that it is still the same.

Thanks for your info Papasmurf

[Towncivilian]

Check the resistance of the knock sensor; see page EC-263 of the factory service manual. Also check the engine coolant temperature sensor (see EC-142) and camshaft position sensor (EC-268).

[cnaug76]

I dont understand what you mean by the resistance of the knock sensor?

Thanks.

[Towncivilian]

Measure the resistance of the sensors at their wiring harnesses using a multimeter.

[cnaug76]

Okay thanks for all your help. Will keep you posted ! I plan on taking a look at it tomorrow and see if these are the reasons why it is acting up.

[cnaug76]

Almost sounds like a coolant temp sensor to me.
A bad Crankshaft position sensor will definitely cause some pretty horrible issues. Its possible the sensor just starts reading all incorrectly once it has warmed up.

Have you heard of any other Infinity QX4 owners with the same problem?

[PapaSmurf2k3]

No, but I've heard of plenty of other vehicles having the problem.

[cnaug76]

Okay and thank you very much again for all your help guys! Will keep you posted

[cnaug76]

I changed the coolant temp sensor, and also cleaned the maf out again, still doing the same thing, sputtering, stalling, and not allowing me to go past 3000 rpms. As soon as vehicle is warmed up, five or ten minutes, vehicle stalls and will not start back up and has to at least let it sit for an hour before I can start it back up. At this point i dont what else to change out,will a knock sensor cause these kinds of problem or could be my maf? any help guys?

[PapaSmurf2k3]

Did the camshaft position sensor check out ok?

[Towncivilian]

Inability to go past 2.5-3k RPMs really sounds like a MAF sensor issue. It's possible for a MAF to be bad despite not throwing a code, oddly enough. Try to follow the diagnosis procedure on page EC-120 of the factory service manual (skip step 1 though since we don't have a CONSULT-II and the malfunction type is unknown).

[cnaug76]

Thanks everyone for all your info. Papa Smurf helped me figure out the problem. I ended up replacing the whole distributor, and it was the cam-shaft sensor that caused this. Im just happy to have this figured out, all over and done with. Spent a lot of money and a lot of time trying to figure this problem out. Thanks again everyone for all your help! I am happy that I joined Nico-club forum.

[PapaSmurf2k3]