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HybridZ

Almost finished and the Z won't start!


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I have just finished putting the Z back together after a few months of sitting on the project. It is an N42/N47 turbo project(I just relized it was an N47 today, I guess I glanced to quick the last time and thought it was N42). It is using all the stock N/a electronics. All I did was bolt turbo parts onto the N/a motor. I would really like to get this motor running in its current setup. Within a couple months I plan another buildup which I have most of the parts for already, including MSnS, Holset H1e, Srt4 intercooler, hks wastegate(will prolly get a Tial instead though) and a greddy BOV(prolly goto TurboXS though)

 

Back to the original problem. I have weak spark, and it seems as though that is the main thing that is hindering the first startup. I did not wire EVERYTHING back up to where it needs to go just because I do not need horns and lights and such, so that is not wired up, so I guess its a possibility that I forgot a wire or 2 in that mess of a harness. The car did run pretty well(vaccum leak) before the teardown, but there was no spark issues to speak of. Could somebody tell me if theres a ground wire or something that I'm missing for the electrical system. I know there is a red and green wire on the dizzy and a red and green comming from the harness, so I hooked that up. I also know that there is a black and blue wire comming from the harness that needs to goto the coil, which is + and which is -? Is one of those random wires in that same bundle a ground for the electrical system?

 

One last question, which port on the dizzy cap is #1? I know off the top of my head is 1-5-3-6-2-4 in CCW order. Every other Z cap I've had had a #1, this one doesn't.

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Most is N/a, but that should not matter at the moment. The J-pipe is not hooked up right now, its running N/a, just untill I can get it started, then I will put on the J-pipe.

 

And yes, it does work, mine was running the same setup a few months ago, but a broken stud caused the intake gasket to blow out. Since then it ran like crap(like 5 minuts after) But everything has been fixed now and its gonna be mean.

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The blue wire is the negative for the coil. The number one spark plug wire is the one that is located at nine o-clock if you stand on the driver's side and look at the distributer facing toward the passenger side. There is notches to locate the cap and number one is the first one above the locating notch on the left side. (standing on the driver's side facing the passenger's side) The fuel injection has a ground that attaches to the driver's side strut tower and one that attaches to the engine on top of the intake on a bracket to hold the harness. The engine compartment harness has a ground that attaches to the firewall on the passenger side. good luck!

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Haven't had a chance to take a look at the Z since xmas eve, because of work and weather. But what I am wondering now is if the ground isn't hooked up-then it wouldn't spark at all. But I get a weak spark, not lack of spark-VERY WEAK spark that is. I know my coil is good, and just for kicks I used another new coil that was great last time I used it.

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Will make sure to do that-I know quite a bit about what grounding issues can do, nissans weakness has got to be electrical, specially on the older datsuns. My old ZX had a few grounding problems. My sentra had an electrical problem. And my new Z has electrical problems. I'll take a look into it whenever I get another chance to work on it, which would probly be this weekend.

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I've tried everything, even used the coil on my sentra, and it works, so the coil is good. I pulled a wire, and put it on a plug and set it on the valve cover. Turned the motor over, for lets say 10-15 cranks, its only sparked twice, yet again, a very weak spark. I checked all the grounds AGAIN, and made sure everything was good, the blue was negative already. I have no idea whats goin wrong. Any other ideas, like a possible connection somewhere that may be disconnected still? Also I used the screwdriver test and my injectors weren't pulsing. Everything worked a couple months ago before I tore it down.

 

The mistake was that I didn't label anything, which wasn't a big deal, because I was gonna scrap the harness and use my MSnS setup. But for certain reasons I am now putting it together with the stock trash again.

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I spray all my plug in connections with electrical contact cleaner then plug and unplug them a few times, I seen too many that look corroded. Back to your problem, the EFI computer does NOT control the spark, power from the battery goes through a FUSE LINK under the hood to the ign. switch and the coil and dizzy. You mentioned that the injectors are not firing, the EFI computer is also powered through a different FUSE LINK. Could be that you have a +12 volt problem instead of a bad ground.

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I am not using the AFM at the moment, I'm just trying to get it started, not drive it. And YES it will run without the AFM, because it would run without it before.

 

I did use that method Paz, and nothing. I will try again this weekend and see if something may have come loose.

 

The reason I am putting it back to stock is to see if its fixed. I was having all sorts of problems(none electrical) and I think I have fixed them all. But before I goto a new harness and computer, I want to make sure its running right again. That way, if all is right now, then anything that doesn't seem right is from the MSnS.

 

I don't wanna have to try and desifer if the mechanicals are right while I'm trying something new(MSnS) that could possibly be wrong. For example, I try and figure out why I'm running incredibly rich and say,"I'll just lean it out", but for some reason now I still have no power, and still running kinda rich. And come to figure, it all turns out to be a blown intake gasket and its causing a pretty nasty vacuum leak. So what I am doing is taking the injection system on there that I know is good, and runs VERY well with my engine, and if all checks out with that then I will step up to MS.

 

Now that I think about it, I don't think I used any fuse links, I didn't think that had anything to do with the spark. I knew that the fuse links had something to do with the FI though, but its always the little things you overlook :)

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Actually when an ignition switch becomes faulty, It'll sometimes make contact and give you 12 volts, sometimes make partial contact and give you 4-6 volts and sometimes not give you anything... It'll eventually wear itself out.

 

I believe I have a few laying around in a box if you want to drive up and pick one up. I'm no longer at the other house, as we moved back in June, but I'm only 15 minutes west of the other house...

Mike

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The contacts in the ign. switch are seperate for crank, ign, and assy. You can run a jumper under the hood from the battery to the ign. coil, I think the wire color on the coil is black/white stripe, not sure, that would power up both the coil and the dist.

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Actually when an ignition switch becomes faulty, It'll sometimes make contact and give you 12 volts, sometimes make partial contact and give you 4-6 volts and sometimes not give you anything... It'll eventually wear itself out.

 

I believe I have a few laying around in a box if you want to drive up and pick one up. I'm no longer at the other house, as we moved back in June, but I'm only 15 minutes west of the other house...

Mike

 

Im gonna test it first, and if so, i may take you up on the offer, thanks.

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I had a similar problem with my 85 RX7 / SBC swap (the one I built 5 years ago, sold, bought back, sold again, and got back AGAIN this past fall!!! Whew.......)

The ignition would power evrything up in the ON position, but when I turned it to START it actually cut out the 12v signal that was suposed to power up the distributor, and the thing wouldn't fire. To test the theory, I 'hardwired' the 12V power wire to the distributor directly from the battery and BLAMO!! (only had manifolds on it.. :lol: ) That's my guess anyway...

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SOOO close, I can taste it. I am going to rip apart my wiring next week, so I just decided to cut up the fuse links and solder them together and it is SOOOOOOO close to running. I can't dial in the timing till it fires up, and I have an adjustable FPR, so its more like a hit or miss type thing untill I get it running. It will actually fire up for about a second then die, But I'm getting closer.

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That's fuel or timing... Check your plugs to see if they are fouled/ wet with fuel...It's no longer an electrical issue in my mind.

 

You could also get a buddy to crank it while you move the distributor slowly and in small incriments. Or get a remote starter switch from sears for $40.

Mike

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