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Need the VG33E guys...for a non-Pathfinder


hawairish
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I got pulled into a helping a neighbor who's got a 00 Quest 3.3L that's not running...I know, sorry, not a Pathfinder, but hey it's more about the engine.

 

Long story short, a few months ago "something" in the engine bay got glowing hot (presuming front cat), and he had some guy do some work on it months ago.  I was told the fuel filter was swapped, a cat was swapped (not the front), and the timing belt was changed (sorta).  He asked me to take a look at it over the weekend, so I did.  The guy who did the timing belt got exactly that far, not bothering to put the covers, pulleys, belts, or hoses back on, and never came back. 

 

I offered to put it back together and see if I could get it started.  As far as I could tell, all the alignment marks on the three sprockets aligned with the dimples on the backing plate, but being a transverse-mount engine, a few things prevent getting a good look at the LH alignments.  I had the timing pages from the Quest FSM for reference.  Got everything reassembled eventually.  Battery was drained, so I got it charged up to 13.5V over the past couple nights.  I threw the battery in, replaced the crappy terminals, and gave it a go.

 

So, here's where I'm at:

  1. 1st attempt, it turned over and started.  Couple turn-overs before it caught.  Rough idle, low idle around 500rpm.  Giving it a little gas almost killed it, but it recovered.
  2. 2nd attempt, turned over and started quickly.  Same rough and low idle, same reaction to gas.
  3. While "idling", I notice some light smoking coming from around the 2-4-6 manifold, but the overhang on the valve cover prevents me from seeing the exact source.  But, does look like it could be coming from the gasket.  I shut the engine off.
  4. For the above, no particular noises.  Engine was running pretty quietly, actually.  After engine off, no hissing or other noises.
  5. Restart attempts at this point fail.  Engine turns over endlessly, but doesn't catch with or without the gas pedal.  Every now at then, the fuel light would come on briefly during starting, but not always.
  6. No engine codes, stored or pending.
  7. Fuel pump and ignition fuses good.  Full tank.  When key in, turned to ON, the fuel system priming is audible prior to starting.
  8. I did pull the distributor cap and rotor to check the contacts, they were ok.  I saw no indication that the distributor had been removed or adjusted recently.

 

My best guess it that the front cat core has degraded and clogged the exhaust, but would that be a logical reason to explain why it started fine initially but then wouldn't start?  Would built-up exhaust pressure do that?  For this engine, the 1-3-5 (towards firewall) manifold routes forward and joins the 2-4-6 manifold as it goes into the front cat, which is located between the engine and radiator.  I never saw it when it was reported glowing, and my pyrometer during a few minutes idling showed it reaching 350°F.  I don't know what's normal.  The O2 sensor is conveniently on top and might allow me to peek into the cat, but I didn't try to remove it because everything was still hot.  He (neighbor) did say a cat was replaced, but I didn't do a visual inspection underneath...perhaps the issue was farther upstream.  The nuts on the 2-4-6 manifold did look like they had been tightened at some point, so I don't know if it was already inspected otherwise.

 

Any ideas?

 

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Chatted with my neighbor today.  Confirmed that the last guy who worked on it pull the front cat and exhaust off to replace the rear cat, and he confirmed the system was still free flowing.

 

Started it up today with similar symptoms as before, except the 2nd start today it idled closer to 700rpm.  Same smoke, but I suspect it may just be heating up some oil/dirt build-up.  An obvious hazard either way.  Still no codes, though.  Did notice that the temp gauge didn't budge and the radiator and hoses stayed cold.  The slightest touch of the throttle body cam immediately bogged the engine initially, but I did get to one point where revved a tiny amount.  The engine eventually stalled out right as I was about to try the throttle again.

 

Still hoping someone's come across this issue before.

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The first thing I would do is verify the valve and ignition timing. It could be running a tooth or two off. The smoke is probably just oil/coolant/penetrating oil burning off on the manifold.

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I’ve just now seen this thread.

It does sound like it’s a tooth off. If I’m remembering correctly, and Mrelcocko will have to confirm, when it’s a tooth off it does exactly what it’s doing with you.

The timing belt on this engine in a quest has got to suck..

Only other thing I can think of is the MAF sensor or a super bad vacuum leak.

I don’t know how to do the shoutout thing to get Mrelcocko’s attention. He had a tooth off and might be able to help nail down whether or not that actually what it is. I’d hate to dig back under those timing covers for no reason.

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Thanks, guys.  I'll give it another look eventually.  I was kind of hoping the guy would just cave in and sell it for scrap (I'm not entirely convinced keeping it alive is justifiable), but the same could probably be said of the vehicles I keep.

 

I'd absolutely hate to pull the covers off again to double check the timing.  From the sound of it, the guy who did the previous work was very experienced, but also in his 70's I'm told.  He probably just gave up.  At the same time, it's not clear to me what prompted changing the belt in the first place.  My neighbor isn't the preventive maintenance type (at all), and from what he says, prior to this issue, the van ran fine.  I've got the previous timing belt and it looks fine to me, too.  But yeah, it was a pain to work on.

 

I'll see what I can try for the MAF or other intake/sensor items...anything to avoid pulling those covers.   The fact that the engine almost instantly bogs down when I barely touch the TB cam just has me thinking it's intake related, but I'm still baffled why a code hasn't been tossed yet...but that alone might suggest a timing issue if all sensors register okay?

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When you pulled the distributor cap off was there any reddish/brown/gold dust or flakes? VG33 are known for the distributors failing. When it went on my roommates frontier it would idle, but stall out with any application of throttle. If you’re sure the timing is right id start there. 

 

You would only need to pull the top cover anyway. Line up the balancer first mark with the arrow on the cover, that’s TDC. Then the upper marks should be lined up.

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Oh yeah, I didn’t think about the distributor. That could definitely be it. The 3.3 quest is a good place to find distributors at the junk yard as well as MAF sensors. I don’t think as many folks know about the quest and my local pullapart doesn’t list the quest for interchangeable parts.

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