hard starting issues, changed a lot...still not turning over

[baurox]

So for the past week, I've been having serious starting issues w/ my 99' QX4.

Short story -- 2 weeks ago, starting the vehicle was basically alright, 2-3 secs tops. One day, I ran the tank to just about empty (was not crossed the E yet, but was about 1/2 way on it), but never technically ran out of gas, so headed home before going out again to fill the tank. Caught a quick 30-1hr nap, was getting ready to go to the gym, went to start the car and it would not turn over for the life. Went to go buy 5g of fuel, poured it into the tank, didn't start right away, but after couple cranks it eventually started.

That's when the hell started. (last couple days) I've been able to crank the car (sounds like a great crank) but it just will rarely kick over to start, would just be on the cusp line of wanting to start, and it would take several cranks to finally turn over (if it wanted to).

I Replaced the fuel filter (on the right way) roughly 6-7k miles ago, and installed a brand new fuel pump, fuel relay, TPS (set correctly), distributor cap, distributor rotor (rotor was pretty shotty black looking)....

All those, and STILL the car just cranks wanting to run, but it's very rarely now it will run.

Here's the best part of course, when the car finally does turn over and runs, it stays running, never really an issue...but RARELY (1 out of 15-20 drives) i'll get an RPM complete drop for 2-3sec, but will kick back in and run fine. I have a new air filter / MAF as well, haven't installed them yet, but I don't think the MAF has any effect on starting the vehicle, right? Like enough to make a difference.

I'm completely lost now with wondering what to do. Fuel pressures are good, I mean...I'm completely lost...lol. I've only had codes for the TPS, and those were corrected w/ the new TPS. No other codes for any of the issues I'm having, the light isn't even on now either.

Now you know pretty much everything, but any other kinda help would be awesome.

Thanks!

[Towncivilian]

The MAF certainly does have a play in starting the vehicle. Since you've already purchased a new one, try swapping it out and see if the situation improves.

[baurox]

Ok, swapping it out this morning...but, if the MAF has a job in starting, why does the car basically run perfect once started and not really any issues ? Other than the rare RPM drop but comes back right away.

I mean, starting the car is like me getting laid w/ kate beckinsdale, it's barely turning on, but it cranks perfectly...just needs that little ooompf to kick over to run.

PS> Should i be doing anything w/ the battery negative when replacing the MAF ? Like do i need to restart the comp or something basically.

[baurox]

I replaced the MAF w/ the new one, and a new air filter...has ZERO effect whatsoever to my issue. Car still just cranks hard but doesn't run.

Ideas ?

[baurox]

Ok, so I'm getting super frustrated with this issue. Can anyone tell me what controls or sensors are involved in starting the vehicle?

Because my car runs fine once started, which leads me to being a sensor or electrical device that's not helping my car turn on from cranking. Car has a great crank, but its just missing that last piece to helping it start.

I've replaced the tps sensor and maf sensor, and fuel pump relay. Tested the Fuel / air pressures and are perfectly fine because I have no issues once the car runs.

Something isnt communicating correctly during the crank to start the car. But like I mentioned, the car runs great once started and running.

[baurox]

Would the crankshaft position sensor have any reason to function for my situation?

Its not throwing a CEL, but my issues are intermittely, so woulldnt think it would throw the light.

Ideas?

[yngw13]

Oops NVM below...turns out you are cranking











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Have you tightened and cleaned the battery terminals?
One of them might not be clamping on firmly.
Try cleaning up the posts with a battery post cleaner brush.
then re install clamps...

[Towncivilian]

Yes, CKPS can cause starting issues. Inspect it according to page EC-281 of the factory service manual.

[baurox]

Found out it was the cam sensor which is in the distributor, so have to replace the distributor since the sensor is inside of it and they don't make that part and it just easy to replace the whole distributor.

[baurox]

Nope, the distributor DID NOT have any effect.

Last 3 things I have to do are:

- Clean the fuses (going to clean them all, no chances)
- Replace the crank sensor
- Worst case...change out the ECM

Anyone w/ ideas, please help

PS> Still no codes at showing either. This has been a complete nightmare on whatever is causing this issue.