New Guy Seeks Your Wisdom (Same Old!)

[Fast_eddy]

Several years back I bought a 1992 f150 and redid, over time, pretty much the entire vehicle. Looking back, it would be much easier to do a second time. Well today I picked up, as partial trade for my Mini Cooper, a 1990 pathfinder SE, vg30e. I am somewhat familiar with the engine, as I once owned a vg30de in my 300zx.

 

It has only 93k on it, and has been sitting for some time. It is running a bit rough, needs two window actuators, a couple switches, and has some creaking from the front end. Otherwise in great shape. I bought bought the usual suspects: distributor cap, rotor, plugs, wires, fuel filter, air filter. I also read up a bit and picked up a coolant temp sensor. So... The question is... If you were starting with a 90 pathfinder with 93k on the clock and just wanted it to run well and be reliable, is there any must do repairs or replacements you'd suggest?

 

Thanks for your input... It is appreciated.

 

-Fast

[adamzan]

Timing belt and water pump, all fluids, service the brakes, o2 sensor, clean the MAF sensor, new thermostat, and tension/strut rod bushings.

[Slartibartfast]

And check your frame!

[Fast_eddy]

Those sound solid. Thank you.

 

Right now I have to deal with its missing. Acceleration, especially at low rpms, is rough. Sounds like a tractor. Did the cap, rotor, wires, and plugs today (along with the coolant temp sensor just for kicks) and it is running better, but there is a miss that is still there (maybe even more pronounced with more power in the other cylinders). Was reading up on the vg30e in a maxima forum and for this issue those guys seem to think the injectors are the likely cause. What do you guys think?

 

If I can cure this, the water pump and timing belt job will be next.

[adamzan]

What about the timing? Distributor itself look like it was messed with at all?I would get a timing light and check. Timing belt could have jumped a tooth as well. It would run like a bag of @!*%, but it will run.

[Fast_eddy]

It absolutely could be the timing. Nothing looks like it has been messed with... The thing seems like it hasn't been administered any maintenance in a decade. Was sitting just in a garage (which could also mean an injector is just clogged, but if that is the case, I may just have to replace regardless). I def need to get a timing light though (as my ford needs a new distributor soon anyways).

[Slartibartfast]

If you suspect an injector is stuck open or closed, or clogged, try pulling the plugs and see if one cylinder is notably richer/leaner than the rest.

[SpecialWarr]

Or you could get a long thin rod and set it onto the injectors one at a time and listen for clicking through the rod. It won't tell you if the injector is clogged but it will tell you that it's operating easier than trying to unplug injectors.

[Fast_eddy]

SO... Found a great deal on a set on injectors. Job took me longer than expected. Replaced all six, cleaned the throttle body, replaced the intake plenum and tb gaskets. When i started her up... WOW! Couldn't believe how much power I had been missing! She ran like an absolute dream!

 

Then... This afternoon I got a car wash. After vacuuming, I started her up, and the idle was over 2k. When I pulled out, with minimal throttle, she ran fine, but when I gave her any gas at all, the engine completely bogged down. Then when releasing the gas pedal, she would start firing normally again at minimal throttle levels. Def not burning all the fuel whenever throttle is higher than a minimal level. Also... Ice cold AC on the way there (and since I've owned it), but no AC after the car was either.

 

I'm going out to clean every electrical connection I can, clean the grounds, apply dialectic grease, and then check the pressure on the AC. Anything I should specifically look at? The main relay maybe? Help is appreciated... This has been a challenging project and this car was business was a bit demoralizing.

[Fast_eddy]

Cleaned every electrical connector I could, including all the relays along the body (even the three that required washer reservoir removal) and coated all in dialectic. Still the same problem. Starts, idles high, runs ok right away, but give it gas and the engine bogs way down. The AC compressor is not engaging either (though the system is fully pressurized). I'm at a loss for how the compressor is related to this power loss/bogging down of the engine with throttle, but because of the immediacy of this happening after a car wash, I have to still believe it is something electrical somewhere. Help is appreciated.

[Fast_eddy]

Quick update: went to check ecu for codes. Light is solid red when key is placed in the on position, and I can't get it to do anything else. It just stays solid red no matter how/when/where I turn the diagnostic dial. Even if it is a bad ecu, I'm just not sure how moisture would trigger it (being under the seat and all). The precious equation was

Moisture from car wash = bogged engine (running rich) and AC compressor won't turn on. Two separate connectors/relays? A common ground? A bad ecu? I'll have to take it to a shop tomorrow if I can't figure out a lead or two! Help!

[Slartibartfast]

There are a lot of connections under the dash, especially the super multiple junction on the driver's side, and if the windshield is leaking, it could be leaking into that mess. You might try turning the A/C on, then spray around with a hose and see where you have to spray to make it crap out again. Maybe try spraying the engine bay around the MAF sensor and the compressor as well. I would also dig around in the driver's footwell looking for moisture, opening plugs, that kind of thing to see if you can find anything after spraying.

 

Odd that it won't code. I don't imagine it's a moisture issue given its location like you said (unless you've been fording rivers). I'm not sure I've heard of an ECU not running codes properly. You can also run codes from the black diagnostic connector under the dash if you don't mind screwing around with some LEDs and a pushbutton--there's a writeup on Infamous Nissan for putting the diagnostic lights on the dashboard that gives you a pinout. Might work if the pot in your ECU just isn't working right or something.

 

Edit: Come to think of it, I don't think you'd have to rig new lights to read codes from the diagnostic plug, the lights on the ECU should flash like usual if you can trigger them from the diagnostic port itself. If you look up the thread on Infamous, find the diagram of the plug that shows the switch hooking into pins 4 and 3. 4 and 11 (IIRC) is also shown but didn't work on mine, I think it's for the four-cylinder or the TBI or something. You could probably screw around with a paperclip and get the LEDs on the ECU to spit codes that way, though you'll need somebody to watch the ECU at the same time unless you have really long arms. Again, this is assuming it's just the little trim pot on the ECU that's not right.

I'd want to track down that water-activated electrical gremlin first though.

Edited June 21, 2016 by Slartibartfast

[Fast_eddy]

That is a good idea. The problem is: two days in the Florida sun after this happened and everything is dry... But the problem is still happening. Today she started right up, then stalled. Then she started again and I could give her gas in park or neutral and the engine did fine, but the second she was in gear, throttle just completely flooded the engine and I couldn't accelerate. Only by barely using the throttle could I keep the engine from flooding. AND the compressor still isn't coming on. From a truck that pulls like a beast with ice cold Ac to a truck that won't accelerate and has no AC in a ten minute span (of a car wash) is a tough pill to swallow!

 

The windshield certainly doesn't look well sealed, but I poured a gallon of water over the stripping and nothing seemed to get wet inside.

[Fast_eddy]

She is in the shop. I will update if they can figure it out.

 

While checking fuses, I noticed the "shift lock" fuse was blown. When I replaced it, it immediately blew again. I have no idea why the shift lock even has a fuse in the first place...

[ThaBigPerm]

Those sound solid. Thank you.

 

Right now I have to deal with its missing. Acceleration, especially at low rpms, is rough. Sounds like a tractor. Did the cap, rotor, wires, and plugs today (along with the coolant temp sensor just for kicks) and it is running better, but there is a miss that is still there (maybe even more pronounced with more power in the other cylinders). Was reading up on the vg30e in a maxima forum and for this issue those guys seem to think the injectors are the likely cause. What do you guys think?

 

If I can cure this, the water pump and timing belt job will be next.

 

First hand, recent experience on those injectors. Had a low-end stumble/hesitation. Nothing I did made it go away. And I did *all* the usual stuff, plus a few other things it needed: plugs/cap/rotor/wires (cheapos then proper NGKs) ... eventually had to replace the distributor itself as the bearing was self-destructing and debris was interfering with the position sensor, making it intermittently undriveable. New IACV. MAF subharness ground fix. Fuel filter. But ... when I replaced the injectors, I suddenly had a VG30E that ran almost as good as when it was new (all the other new bits didn't hurt, I'm sure). The screens on the injectors were dark brown, almost black. I imagine sitting for extended periods can gum up the works moreso than high mileage. Many cans of "injector cleaner" didn't to the job, but swapping them out sure did.

[Fast_eddy]

Yeah mine ran beautifully after the injectors. Felt like a new engine (I too did a bunch of other stuff, but none of it mattered until the injectors were in, as I had a bad miss). It was great... Until the now infamous car wash, of course!

[SpecialWarr]

The only other thing I can think of is the fuel pressure regulator on the back of the intake / its vacuum hose / a vacuum hose issue.... maybe pirate air from the intake boot to the throttle body?

[adamzan]

What did the shop say?

[Fast_eddy]

Shop took THREE months to "evaluate" it. It was sitting for most of it, they put maybe two hours into looking at it. Their evaluation for the engine issue was a bad MAF. Installed a new one today and the problem persists. Now it stalls at start up, when put in gear, and then bogs completely with any throttle. If I keep the RPMs low I can get it up to speed, but the second i give it gas, it bogs right down. Next step is probably to pull the ECU as the current one won't go into diagnostic mode, which makes the process that much harder.

 

 

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[Fast_eddy]

Both problems (ac clutch not engaging and engine bogging/flooding) were solved by replacing the ECU. I was planning on selling this after accepting it as a trade... didn't expect a five-month ordeal! She runs great now though. Wish I had room to just keep her around long term!

 

 

 

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[Slartibartfast]

Huh. That's an unusual thing to fail. Good to hear you found it in the end, though.

 

Nice picture!

[Cuong Nguyen]

Man that thing looks pristine!

[Fast_eddy]

She is pretty damn clean, inside and out. A 1990 and only 93k on the clock!

 

 

 

 

 

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[Cuong Nguyen]

So jelly. I've been looking for SE seats to swap in my XE

[Fast_eddy]

As a completely partial and entirely self interested party, I'd say anyone who has wanted to do anything to their pathy should just pony up and buy this gal!

:-)

 

 

 

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