I'll start with an apology for the long post.

I just finished swapping the VG30E/AT in my max with the same from a donor car (that had been sitting for a year, but was running before that). I replaced the front oil seals, timing belt and swapped the whole injector rail from the old engine (old engine has a blown headgasket). I did all the vac tubes and cleaned all connectors as I went.

Just finished the swap last night and started it up, rough idle/vibration on startup, but not super bad. But when under load (AC on, or put tranny into drive) the RPM's drop from 1000 to ~500 and its really rough/vibration. If I rev the engine it is smooth.

At first I was thinking IACV so I cleaned that, didn't help, so replaced it with the one of the old engine. No good.

No codes except O2 sensor.

Anyway, after a lot of checking I find that all the front cylinders (2,4,6) aren't working I didn't check straight away because at idle it doesn't look like its running on 3 cylinders! I found this out by pulling spark plug wires, no change in engine running.

I was hoping I had just forgot to connect the front bank injectors...no suck luck. They were connected and I checked them again, all within spec (all ~12ohms). When pulling the plug wires out they spark against the case, so I'm guessing that means they are getting juice. I swapped wires and cap to check, no good.

I pulled the sparkplugs and while they weren't dripping wet you could tell (compared to the back working ones) that they had liquid on them. So I'm guessing they are getting fuel. Took a wild guess and swapped over the camshaft position sensor, no help.

Ok, so what else to check? What would cause the front bank to not work?

I'm starting to think that maybe I stuffed the timing belt change (off by a tooth or something). It’s the first time I have done one on a maxima, but I have done a timing belt on my 300zx VG30ET before. Everything lined up perfectly.

I just found that my inhibitor switch on the AT is not working, I can start the car in drive and the diagnosis doesn't run. I don't think this affects my symptoms (my idle issues happen turning the AC on as well)_, but I will fix the switch.

I'm pretty much at the end of my list of stuff to check. If no one has any ideas I'll prob pull apart the front to get to the timing belt to check ad then try swapping ECU's? Bah.

 

I haven't done an engine swap myself but I recall reading over and over something about 2 plugs that are interchangeable. One of them being a bank of injectors and Im not sure about the other. Your injectors may ohm out fine but do they have voltage? Im sure someone can chime in and point you in the right direction.

 

Hmm, thats interesting. I've had another look and can't see any other connectors that would fit in that area. The one next to the front bank injectors is for the IACV and has a lot more pins. I'll have another look and search for it

I just did the screwdriver Stethoscope trick and it doens't seem like the front bank injectors are working...so maybe it was't fuel on the sparkplugs.

So that poses the question, if they all (the 3 front ones) all ohm out OK, are connected...why wouldn't they be working? Back to the timing belt maybe?

 

Check the compression. I'm hoping that you did so before installing the engine..

"no suck luck"

 

Compression was good.....Reizy was right. I am an idiot :P

The IACV/front injector bank connectors are the same as two that go to the tranny. That is also why the inhibitor switch wasn't working. I can't belive I wasted a whole day on two missed connected connectors

Anyway, the front bank is working....except for injector #2. It sounds like its working, but I will ohm it after a couple more beers Might have been stuffed connecting it up the wrong way. At least I know what it was know...thanks again Reizy

 

well the thing is, the injector leads on the ECU expect a certain resistance to be present. If you connect it wrong, to the inhibitor connector, then it sent a full 12v down almost-0-ohm circuit... which can (and for the last guy whose dumbarse mechanic connected these wrong, DID) fry the ECU. So if ohm-testing the injectors doesn't work out, then you might need to get a working ECU.

 

Yep, you were right, ECU was stuffed. I have the whole car from the engine swap so it wasn't a problem swapping them over. Guess that teaches me to be in a rush...everything was going well until then lol.