97 pathfinder rough at low rpm and stalling

[andhan]

Hello fellow nissanheads !

I've got a problem
97 Pathfinder se 4x4 stick
Just changed the water pump, timing belt and front cam seals, put it all together, starts and runs - success ! - I go to sleep exhausted
Next day go to drive it, as soon as it warmed up started 'missing', rough running even stalling when accelerating from stop.
If I let the rpm build up very very very slowly past ~2K rpm everything is normal , can rev high, has power, etc but if I tap throttle from idle it gets really rough huffs, puffs and stalls. starts up again ok.
seems the wormer it gets the worst it gets
I get a code 325 for knock sensor, nothing else

could it be a vacuum leak that makes it run lean ? is something clogged ?
The cooling system was really neglected since I got this car
I'm kind of a shade tree nube mechanic never the less I'm an electronics tech and can measure stuff etc
What do I do ? ,no really, how to troubleshoot this ?

Thanks a million for the help , what more info can I give you ?

[ARKQX33V6]

Did you verify the idle timing and dynamic advance after you buttoned it up?

[andhan]

will do it tonight and post results
need to google dynamic advance first
(willing to learn)

[andhan]

Ok I set the timing with the TP sensor disconnected to 15deg it was over 20something
plugging the connector back in makes the engine sound different a bit,
revving up causes the timing to auto advance by alot while looking at the marks with timing light so I guess that means the dynamic timing advance is working.
I'm sure the timing being off 'muddied the water' a bit but the problem still exists
It seems the problem is somewhat intermittent now
Not every time when throttle tapped gently from idle causes rough running usually ending in stall but maybe about 70% of the time
idle is smooth
bringing rpm up very slowly does not cause the problem
it's still pretty undriveable thought

What do I check next ?

[ARKQX33V6]

Verify your throttle connections, WOT and transmission must relate and when they do not the ECU gets confused, bad enough it will toss up a weird set of codes that are not related except by speed and gear set.

IA control must be good, EGR if plugged will cause this. Check vacuum lines are right and no leaks. With timing too far fwd and now returned check spark at each plug. Make sure plugs are not cold type and clean and gap correctly with a wire feeler not a blade.

Verify coolant temp sensor it can cause high speed idle when warm. If still getting knock sensor code, check spark, timing, coil, transistor in distributor...and wires and knock sensor.

By the way what gasosline are you using 87,99,91? If regular and you are using 89 or higher you may be coked up

Check distributor especially inside of cap no carbon tracking, clean slit disc of dust and LED receiver.

[andhan]

always using 87 octanes

well I got a second ,third and fourth opinions
My mechanic friends were concerned that perhaps i didn't do the tensioner right and it has skipped a tooth
so I took all the covers off again just to check , sure enough everything looked ok
I buttoned it back up again (2 hours)
started it - took a long time actually to start
run perfectly
took it out for a spin
3 blocks down the road it died completely all of a sudden
could not start it at all
we checked for spark
there was none
played around measured stuff finally decided to get a new distributor
put new distributor in ($250)
started right up
runs smoothly ever since
looks like an intermittent problem with a dying part in the distributor - (surprisingly easy to change)

I'm pretty confident my problem is solved

THANK YOU VERY MUCH ARKQX33V6 for your suggestions and emotional support
If you're ever in Petaluma I'll buy you a beer

next project changing blown shock in the k-sport coilovers in the 240sx

[Bluewulf73]

Hey andhan,

Do you recall what part in the distributor? Is it replaceable or is a new distributor necessary?

When you wrote "intermittent problem" did you mean it as a well-known issue or intermittent to you alone?

I am having issues with warm engine stalling to-clean-or-replace-iacv-t570068.html which continues even after the IACV solenoid and fuel filter replacement and MAF and TB cleaning.

Maybe this is something I need to talk to them about when I take the truck back to them.

Any help you can provide would be helpful;

Thank you.

[buhaw12]

It's a common issue is the R50s. Mine died in the same fashion - was doing other work and it just happened to fail at the same time. The distributor is supposed to be replaced as an assembly (other than cap and rotor), so you'll probably need a new one. I believe the root issue is in the bearings so you'd just be wasting time if you try and tear it down and fix it. Make sure you get OEM replacement (learned that the hard way).
BTW is your stituation exactly like he described... "Skipping and stalling at idle, fine above 2k". That was my problem down to every detail, so if not all the symptoms match, your issue may lie elsewhere.

[Bluewulf73]

Hey buhaw12,

Thanks for the response. I was having exactly those issues. I have sent the Pathy back to Nissan since the issue is still not resolved, however it has changed a bit since I put in new plugs, wires, cap and rotor.

Now, what happens intermittently is that, when in gear, at idle when cold, the Pathy's idle fluctuates between 400 and 1000 rpm in a manner which makes it look like a heart beat. ___---___---___ for about 20-30 seconds.

When warm, it almost stalls at idle (at intersections etc.) and just when I think is going to completely stall (car shudders), the idle shoots up to 1500 rpm and then normalizes. I got caught off guard ( not pressing the brake as hard as I should've) and the Pathy lungeded forward about three inches when the RPM shot up. This has happened three times in the last three days (average once/day)

It is driving me nuts, not to mention the new-found danger of running into some other car's behind...

I'll talk to the technician and find out if they have any information on the distributor replacement. Thank you.