VG30 code 51 - injector "analysis"/circuit

[Mr. Pickles]

Hey all, I'm trying to figure out my mother-in-law's Infiniti J30. Under the skin, different intake, etc., its a VG30, similar computer, same error codes, etc. to WD21 We borrowed it while they're out of town, but after a week or so of driving, I went to start it in the driveway and it just turned over. It has around 165K miles. It spun pretty fast from what I'm used to in the Pathy, and the few times I drove the car, so I immediately though dead timing belt and/or no compression, and it didn't have any signs of anything weird when I parked it. I found the ECU in the passenger kick panel and pulled the codes, and I'm getting a code 51, which points to the fuel injection circuit. I've never messed with that stuff, so I wanted to post up and get feedback. I figured if it was really something with the fuel injection, like a bad injector or seal, it would just run really rough, but this thing won't even make an attempt to cough, sputter, or start. It just turns pretty quickly (at least I think so), and that spooked me from a J30/Maxima forum I was searching, where some spoke of similar things after changing a timing belt, and it jumped a tooth, or possibly the belt broke.

 

Anyways, any thoughts? I don't have my camera with sound at the moment to post a vid, and I don't think my old one can record sound, but I'll see. I need to avoid the son-in-law walk of shame with a dead car. Any thoughts on how to test the injectors, or things to check out?

[silverton]

There may not have been anything funny when you parked it, but the weather has been cold and you don't know the last time the belt was changed, it could have broken in the middle of the night. if it's turning over quickly it usually means there less drag on the motor. and if the timing belt broke, that's hardly your fault. it was going to happen no matter who was driving it.

 

Just to make sure, pick a timing cover that's easy to pry back to look at the cam gears and have someone crank the motor and make sure everything is turning.

[adamzan]

Or just check to see if the distributor is turning. I had a code 51 on my wd21 and it still ran it just misfired for a bit on semi warm starts.

Edited January 3, 2011 by adamzan

[Precise1]

x2 on the distributor. Pull the coil wire, remove the cap and have someone crank it to see if it spins...

 

I haven't done any injector work on the WD21s and when I worked on the wife's R50, I got a random misfire cyl#1 code even though it was an intermittently dying injector.

 

I'm getting a code 51, which points to the fuel injection circuit

Purely a guess, but it sounds more like something with the wiring/electronics. Hopefully someone with experience chimes in soon so you can avoid the son-in-law walk of shame!!

 

B

[5523Pathfinder]

There is no distributor on a J30. Engine is the same as the Z32. You should be able to look down the oil fill and watch the cams move while cranking. If it turns over freely, it may have a cold soak issue(maybe injector, maybe plugs). If everthing is moving the way it should, put the gas pedal to the floor and crank it over. This may take a few, but compression should build as you are introducing more air into a "flooded" chamber. It may sputter and eventually rev. Let it run for a few minutes. It may feel like it has a miss, but see if you can get it up to operating temp before deciding anything. Then I would remove a spark plug and inspect. Like most Nissans, these motors tend to prefer NGK plugs. If it doesnt work, check for spark. If you wanna shoot over here to Fife, I can let you borrow my in-line spark tester and go from there. Injectors are known to leak and fail. Also, fuel pressure regulators can fail internally(there are two on top of the engine). Post up what you find! I have a co-worker that lives out your way. If you cant figure it out, maybe I can talk him into stopping by.

[Mr. Pickles]

Thanks for the info. so far, I'll give it another looksie and try stuff out. On a fun note, I've moved on from a slight driver's side valve cover leak to ones that's running down onto the exhaust and smoking. It looks nice when you park it. At least the Acura is on the last 1000 miles till it's 180K service, timing belt, etc. and tires on top of that. Our 4 month old baby doesn't seem to understand or care though... hahaha

[Mr. Pickles]

Sorry for the delay, its been sitting a bit while I've been dealing with issues with our own vehicles, sick, kid, yada yada.

 

YOU ARE THE MAN 5523!!!

 

Thanks a ton, the cam turned fine when turning over the engine. No toasted timing belt, awesome. Didn't get much beyond that last night as the battery died, so I charged it full overnight, then put the gas the the floor and just cranked and cranked for at least a minute. It started to slow a bit like the battery was winding down again, then *sputter* turn turn turn *sputter... sputter* turn turn turn VROOOM! It's aliiiive! Drove it around the neighborhood, and it runs great. I forgot how snappy the little 3.0 can be in that sedan.

 

Now to go put the computer back into the kick panel, and devise a way to explain the trim piece I broke... Thanks again, man!