vg30 HELP!

[MrPhotographer06]

Wrong forum, I get it... but maybe the z31 guys can chime in, or anyone of knowledge.

 

So, to make a long story short,

We bought someone elses project. Yes, I know this usually bites people in the rear and i've been lucky until this.

90 Pathfinder XE, VG30 4x4. Someone swapped the motor at some point in time. Guy we bought it from said it had some sort of sputtering issue, and the battery was stone dead when we went to look at it, but bought it anyway.

Got it home, and my memory is foggy on the timeline but anywho, Gas, ignition module (someone suggested so we tried), and a jump box got it to start. Had a cammed sounding idle, but leveled with LIGHT throttle. any futher it sounded like bad gas/fuel starvation. Changed the fuel filter and gave it a shot. 10 bucks in gas, and hit the road to blow it out. made it 8-10 miles with some smoke but it wouldnt get over 50 mph. coasting to a stop light, it cut off and wouldn't start. Did some research, some said the "hot start " issue was common.

Next day, it took some crank priming but on the 2nd go it would start right up with the same sputtering. People have bounced ideas off me left and right but i've come to no conclusion. I left it in the yard with work and other activities taking precedence, I started back on it last week. Dead battery so I jumped it and it turns over for days and with compression sounds from the exhasut pipe but no start. The fuel pump sounded super weak this whole time so I replaced it. found the lines loose, and spewing fuel so I feel there was a feed problem here. Got that fixed and onto the engine bay.

 12v at the coil harness, but no spark to the dist. using my in-line spark checker. Checked Ohms at the coil, and it read really low, so I replaced the coil. Didnt thing to pull the fuel pump relay during testing, but I used a compression checker on 5/6 cylinders and had 120-150 lbs. (skipped #6..bugger.) Then starter would engage but not turn over.

 

Pulled starter, had it tested and they suggested the fusible link was dying, so i removed it and straight wired it. Still no turn over. decided to pull all but #6 plug again so with reduced compression to get it turning over. Nothing. Pulled #6 and when i just hit the key gas shot everywhere. Hydrolocked. So, I pulled the intake. Found one injector with no reading, 4 injectors with 12.5~ readings and one at 69 ohms... clicked it with a 9v and it went back to normal. All had bad, pinched o-rings. Replaced o-rings, reinstalled injectors and buttoned it back up. STILL NO FIRE.

I'm out of ideas. I guess the crank angle position sensor is what dictates fire from the coil and must replace distributor? I dont know... something happened somewhere. Can anyone help?

 

 

sorry for the long winded post..

 

-Cam

[NewZed]

You could use the self-diagnostic functions of the engine's control computer and get at least a small clue.  The flashing lights.  And if you're using a meter you might as well report real numbers, rather than "really low".  Engine control systems with ignition timing and dwell control use coils with really low primary circuit resistance.  Having a systematic plan would help also.  You said you thought you might have bad gas, but you changed the fuel filter instead.  "Hot start" is mostly associated with the L6, not the V6.  Wrong engine.  

 

It's probably been in fail-safe mode since you bought it.  The picture's from 1990 300ZX but Pathfinder is probably the same.

[MrPhotographer06]

While you are correct, the piece that i read said it should read between 60k-150k ohms... I had something along 15 ohms between the terminal and output terminal on the old coil. I didn't remember the specific number because it was far below the required number.

New coil reads 100k.

The self-diagnostic functions of the ECU  are japanese to me, never could get it to enter the diagnostic mode. I'll give it another shot, but the tutorial I read was stating to wait for the confirmation flashes before turning it counter clockwise and then back to "on"
assuming that "on" is the diagnostic mode, i got a bunch of matched flashes that kept repeating. with it being 10's/1's positioing I got  22,33,44,55 but I'm not even sure if i did it right.

 

22 Fuel Pump.
33 Heated Oxygen Sensor.
44 ECCS Normal Operation

55 No Malfunction.
 

 

so, if its no malfunction, why isnt it starting? not even one half attempt at sparking.

 

While you're right, I figured bad gas, but 5 gallons of new gas on top of the existing gallon in there shouldnt cause it to stop running.

I replaced the fuel filter as the part of tune-up parts i installed at once. Fuel filter, spark plugs, wires. I'm sorry if i forgot to post something in the original post, I work nights and hadn't slept since wednesday night when I posted that last night.. lol I'm pretty much to the point of part out, and scrap the rest just to free up space and funds for the 240 at this point. 

[G-E]

Pathfinders should be ODB1 at least, maybe you can borrow a scan tool?

 

Your CHTS equivalent is in the water neck, and the fsm lists a resistance chart to verify it's in the correct range, though I suspect it's more likely corroded terminals if there's a problem.

 

The coils rarely go bad, but the power transistors do, I would suggest grabbing some spares from a junkyard, the little gray thing with 2 bolt holes that hangs off your plenum on a bent bracket on your model iirc...

 

Your fuel pump could also be gummed up with varnish if it sat for a long time with premium gas (often contains some additives that degrade into waxy goo), dumping injector cleaner in might help, but might make things worse too.

 

Thing is you're trying to diagnose a myriad of moving parts with a questionable history that aren't attached to sensors to throw codes. Rather than getting emotional about it, just clean it up one problem at a time. A VG needs very few sensors to run/start, and only a couple more to run well.

[MrPhotographer06]

Pathfinders should be ODB1 at least, maybe you can borrow a scan tool?

 

Your CHTS equivalent is in the water neck, and the fsm lists a resistance chart to verify it's in the correct range, though I suspect it's more likely corroded terminals if there's a problem.

 

The coils rarely go bad, but the power transistors do, I would suggest grabbing some spares from a junkyard, the little gray thing with 2 bolt holes that hangs off your plenum on a bent bracket on your model iirc...

 

Your fuel pump could also be gummed up with varnish if it sat for a long time with premium gas (often contains some additives that degrade into waxy goo), dumping injector cleaner in might help, but might make things worse too.

 

Thing is you're trying to diagnose a myriad of moving parts with a questionable history that aren't attached to sensors to throw codes. Rather than getting emotional about it, just clean it up one problem at a time. A VG needs very few sensors to run/start, and only a couple more to run well.

I've narrowed it down to the crank position sensor i belive... I have a few z31 friends who are going to get me a few things to try.. hopefully it'll be out of my yard soon.