92 Pathfinder

[ajphilipp]

Quick hello to the community. Just picked up a 1992 SE from the original owner. I'm intent on keeping this nice machine going. Very clean overall, mechanically good but I must triple check everything with detailed post purchase inspection. Early signs showing rough idle (gulp )

112K miles, everything original except those tires.

I once had an '88 which served me well. Crossing fingers for this one and learning how to maintain it properly. Will dive into forums to dig up community experience.

[palmerwmd]

Wow it looks gorgeous!
In great shape, thanks for including the pics with your intro!
Do you have a plan for prophylactic' maintenance if everything is original? ( like belts/hoses etc)

Welcome to TheNissanPath your new home away from home!

[ajphilipp]

Wow it looks gorgeous!
In great shape, thanks for including the pics with your intro!
Do you have a plan for prophylactic' maintenance if everything is original? ( like belts/hoses etc)

Welcome to TheNissanPath your new home away from home!

Thank you for the welcome and question. Some good and maybe bad news

Good:
I have completed

• Timing belt, tensioner, water pump, plugs, wires and rotor and valve cover. No leaks

The bad

• Rough idle still there
  Bit of smoke on cold start but no sign of coolant loss, no overheating
  Rough idle goes away once you are driving and drives great
  One mechanic guessing that a valve may be sticking.

hard to know what to do next. ugh. Need a truly knowledgeable nissan mechanic.

[ajphilipp]

One update;

> Mechanic says that he pulled plugs and plug #4 was black
> Compression was fine on all cyclinders
> Put new plugs in and then checked and it was also black * after he left it out to dry
> He suspects either a valve spring, lifter or not sure what else.
> I've brought it home and will use it for a while. Still drives fine when not in idle

Seeking ideas/opinions. ugh

[palmerwmd]

Considering how old the vehicle is and how little you likely paid and how good the functionality of the vehicle I believe even with your issue you still did well.

[smj999smj]

It was not uncommon for the hydraulic lifters to tap on these engines, but even then, I don't recall ever seeing one fail to the point where it caused a misfire? Even still, that or a broken valve spring would have shown up in the compression tests results. It's possible it could be a bad fuel injector leaking down, causing the plug to gas foul during start-up and then burn itself clean as you drive it for awhile. You could try doing a fuel pressure leakdown test to confirm that. Another possibility is what I have going on in my 03 Frontier: leaking valve stem seals. Similar to the bad injector scenario, oil leaks into the cylinder while parked and tends to foul the spark plug at start-up. I get a bit of a misfire and some blue smoke out of the tailpipe, but once I drive it for a while, it clears up and runs great. In the injector case, I would expect to see a little black smoke out of the exhaust at initial start-up. BTW, do you know if that white leather is original to the vehicle? I've never seen white leather in a WD21 Pathy. It looks great, but I was just wondering if someone may have had it re-upholstered in the white leather?

[ajphilipp]

Update: 2nd mechanic visit. He believes the cylinder 4 may be running too rich due to injector. Suggests fuel cleaner as first step for a couple of weeks. If that doesn't work, swap out the injector. In that case, he suggests replacing them all.
Will try that out and hope that is all.

[ajphilipp]

Thank you. The white leather appears to be original. The original owner did not strike me as someone who would ever make any modifications. The entire care is super clean all original. The leather is a bit beat up but no tears, will try to keep it going

It was not uncommon for the hydraulic lifters to tap on these engines, but even then, I don't recall ever seeing one fail to the point where it caused a misfire? Even still, that or a broken valve spring would have shown up in the compression tests results. It's possible it could be a bad fuel injector leaking down, causing the plug to gas foul during start-up and then burn itself clean as you drive it for awhile. You could try doing a fuel pressure leakdown test to confirm that. Another possibility is what I have going on in my 03 Frontier: leaking valve stem seals. Similar to the bad injector scenario, oil leaks into the cylinder while parked and tends to foul the spark plug at start-up. I get a bit of a misfire and some blue smoke out of the tailpipe, but once I drive it for a while, it clears up and runs great. In the injector case, I would expect to see a little black smoke out of the exhaust at initial start-up. BTW, do you know if that white leather is original to the vehicle? I've never seen white leather in a WD21 Pathy. It looks great, but I was just wondering if someone may have had it re-upholstered in the white leather?

[palmerwmd]

Update: 2nd mechanic visit. He believes the cylinder 4 may be running too rich due to injector. Suggests fuel cleaner as first step for a couple of weeks.

Thats not a bad recommendation.
Or u can take it one step further.
There are shops that do specific on the bench injector cleaning with BG44k.
or you can put BG44k directly in the tank.
Its the same as Chevron techron except more concentrated (Chevron licenses this ingredient from BG44K)

[ajphilipp]

Thank you for the recommendation on the BG44k. I wonder if it is different from what I tried.
Update:
> I've run 200 miles after using Lucas deep fuel cleaner
> I added a bit of Lucas injector cleaner at about 150 miles

Result: No change. Still a lot of smoke on startup and goes away after a few minutes. My sense is an injector which is stuck open. Maybe two.

Next step:
> I just ordered and received 6 injectors. Hitachi injectors for Nissan. I searched around to find OEM ones but at a decent price. I'll try to schedule time to swap them out. I'm not comfortable doing the job (plenum, manifold etc) myself yet so will find someone with experience.

he

[VStar650CL]

Next step:
> I just ordered and received 6 injectors. Hitachi injectors for Nissan. I searched around to find OEM ones but at a decent price. I'll try to schedule time to swap them out. I'm not comfortable doing the job (plenum, manifold etc) myself yet so will find someone with experience.

Hitachis won't give you any grief, they're good stuff.

[ajphilipp]

Update.
This is becoming hard to truly pin down root cause. As you can see in the pictures, white~ish smoke with a little fluid run-out on cold start. Goes away after a few minutes. Then if i let the truck site for a while, I see a little bit of it again.

Mechanic 1 - Did 2 block tests, compression and radiator tests. Everything passed and he says its not a head gasket. He says bad injectors and the best thing to do is swap them out. So i bought OEM hitachi ones and need to schedule the swap out

Mechanic 2 - He did not test anything but says its a head gasket because the smoke is white. He claims if it was rich fueling, the smoke would be darker and black.

Hard to know what is what. I've already bought the injectors, so guess I'll start there. Ugh

Images located here
https://ibb.co/CsgPkz3
https://ibb.co/H2yV0Kz

[VStar650CL]

Get a sniff of the smoke and not just the color. Coolant will smell like coolant, oil will smell like oil, and fuel will smell chokingly-chemical.

[smj999smj]

If replacing an entire set of injectors, I usually replace the fuel pressure regulator while I'm in there. The diaphragm inside of them can fail over time and you are already at the fuel rail when replacing the injectors.

[ajphilipp]

If replacing an entire set of injectors, I usually replace the fuel pressure regulator while I'm in there. The diaphragm inside of them can fail over time and you are already at the fuel rail when replacing the injectors.

Yup. good idea.Thank you, I did not think of that nor did my mechanic scheduled to do the work mention it. Most mechanics not interested in doing the injector swap, one quoted me $700 not including parts. I passed on that. Found OEM injectors for about $85 a piece and I finally found a mechanic willing to do the injector swap scheduled for 3 weeks from now.
I'll have to search if OEM fuel regulators are even still available. Not sure mechanics will do the work with out certified OEM parts which i understand.