I have a lot of questions about my new 240sx - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

DiscoStillSucks · 01-20-2015, 07:31 PM

So I just bought a 1991 240sx and I am having some serious problems that almost make me want to give up already, this is my first time on this forum so forgive my lack of how this works

The story of the car:
I bought it from a guy (we will call him Jack) and it was originally his buddies car (we will call him Billy). So Jack allowed Billy to live with him for sometime, all the while Billy owned this 240sx which was his daily driver. Billy began to do things to the car (will list mods i know of in another section). Well Billy had lived with Jack for sometime and he left the state, and left Jack with the car as a way of repaying his debt of living with him. So Jack had the car that he doesn't really know what all happened to it.

Mods I know of:
"Jack" told me that "Billy" had put high compression pistons in, there is clearly an MSD ignition system in the car, an AEM air intake, and some kind of full aftermarket exhaust (from block down)
Now for some reason Billy decided it would be a good idea to move the ignition from the key to a switch inside the ash holder behind the stick (start of problem #1) [I will go into detail of each problem individually]
Billy also thought it would be smart to hook up the turbo timer, an Turbo Retarder Dial thing, and all the while hooking it up REALLY janky (Problem #2)

Problem Diagnosis:
#1: The cheap plastic ignition switch snapped in half, of course after i bought the car, which it already had trouble starting (problem #3). Now, no matter what kind of switch i hook up to it, the starter will NOT even begin to turn on. So i took the console out and found that he decided to steal power from the cigarette lighter from one end, and then there is a little white wire that goes in the opposite direction. After VERY PAINFUL following of this wire, I found the wire going through the firewall and into some type of plug that connects to i dont even know what. and after messing around with many things, the starter still wont run

#2: The MSD ignition box is half useless. The specific one he got was made for a turboed car, which this one never was. So there are wires all around the pedals just dangling around, and they lead to the Retarding dial thing, and the turbo timer which i dont know if they work because we cant turn on the car to find out. Also, we found that a lot of the wires lead to nothing and there are A TON of loose ends of wire that connect to nothing all through out the engine bay.

#3: The car would run, and I actually drove it around the block before buying it (2 days ago) and it sounds fine, but has a terribly hard time starting and staying running at first. The car also doesn't seem to make as much power as it should (problem #4), especially with high-compression pistons. We did find out that 1 of the cells in the battery are bad, but even with a battery jumper/charger the car wouldnt start easy.

#4: I went to do a compression test (today) and this is when the starter switch decided to break, so i was unable to test the compression because the car wont turn over and we had got busy on trying to fix that.

Main questions:
What am i supposed to do with all these loose wires when some of the MSD box seems to actually be hooked up and other parts dont?
What should i do about the switch start set up? How do i change it back to the original?
Where can i buy more wires and learn how to wire it?
What should i do about the turbo timers and boost retarder dial that goes through the firewall and connects to the msd box?
Should i keep the msd box and how do i make sure what to do with it?
What do i do about the wrapped bundle wires that you cant see what is in it?
By the msd box one of the bundles of wires were unwrapped, and one of the wire's insulation is completely melted off, what should i do about it?

Misc:
The car also has a S-AFC II by Apexi hooked up and it works when the engine runs, how do I read and use this thing, or is it useless?
Why would there be all this turbo stuff on a high compression built engine?
There was also a random oil pressure gauge, not hooked up of course, shoved down in the engine bay,what am i supposed to do with it?!
I have so many questions and I know i went in definitely not as prepared as i thought i was. I almost need to find someone around me to help

Sorry for the overwhelming post, i just have no clue what to do with it after only 2 days of owning it. I am so overwhelmed by problems

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dbeiler · 01-20-2015, 10:26 PM

You need to find some help in the form of a local friend with some electrical experience. Option 1, you can count on your car being down for a few days while you sort through the wiring mess, returning everything to as stock as possible. Option 2, you can fix the starter wiring and drive the car, while dealing with hard starts, battery parasitic drains, ignition issues , and wiring shorts. I recommend you restore all the electrical wiring to the factory diagrams. It's much easier if you have another identical vehicle close by to "mirror"

Gorman240 · 01-22-2015, 05:41 PM

If it were me, i would personally take the wiring harness out and all of the msd igniton & apexi controller stuff. Then i would search on the forums for an uncut factory harness that you could replace it with. Then install the new/used uncut harness. It may be the easiest option for you but it would require a lot of work.

Dealing with other peoples wiring "solutions" can be a bigger pain in the butt than simply taking it all out and replacing it all. I say this because you could spend countless days tracing wiries, finding out what the previous owner did to get power to the msd coil, or power to the starter. It would be much more time efficient to gut the wiring and start over with an uncut, clean wiring that you can follow along with on a factory diagram. In the end its either figure out previous owners jigsaw puzzle, or start over from scratch. GL

Kingtal0n · 01-29-2015, 09:28 PM

This is why there is a premium on a non-modified 240sx.

-that is a BTM(boost timing) box and the SAFC to control larger injectors
-the engine must have been on turbo at some point.
-High compression puts additional wear on the starter.

I recommend as others have, either go back to stock using an oem donor vehicle, or just drive the donor vehicle while you tear apart this one.
Take a picture of the injectors next. Also it wouldnt hurt to pressure wash the engine bay, inspect the oil seals of the engine.

01-20-2015, 07:31 PM	#1
DiscoStillSucks Join Date: Jan 2015 Location: St. Louis, Missouri Age: 27 Posts: 1 Trader Rating: (0) Feedback Score: 0 reviews	I have a lot of questions about my new 240sx So I just bought a 1991 240sx and I am having some serious problems that almost make me want to give up already, this is my first time on this forum so forgive my lack of how this works The story of the car: I bought it from a guy (we will call him Jack) and it was originally his buddies car (we will call him Billy). So Jack allowed Billy to live with him for sometime, all the while Billy owned this 240sx which was his daily driver. Billy began to do things to the car (will list mods i know of in another section). Well Billy had lived with Jack for sometime and he left the state, and left Jack with the car as a way of repaying his debt of living with him. So Jack had the car that he doesn't really know what all happened to it. Mods I know of: "Jack" told me that "Billy" had put high compression pistons in, there is clearly an MSD ignition system in the car, an AEM air intake, and some kind of full aftermarket exhaust (from block down) Now for some reason Billy decided it would be a good idea to move the ignition from the key to a switch inside the ash holder behind the stick (start of problem #1) [I will go into detail of each problem individually] Billy also thought it would be smart to hook up the turbo timer, an Turbo Retarder Dial thing, and all the while hooking it up REALLY janky (Problem #2) Problem Diagnosis: #1: The cheap plastic ignition switch snapped in half, of course after i bought the car, which it already had trouble starting (problem #3). Now, no matter what kind of switch i hook up to it, the starter will NOT even begin to turn on. So i took the console out and found that he decided to steal power from the cigarette lighter from one end, and then there is a little white wire that goes in the opposite direction. After VERY PAINFUL following of this wire, I found the wire going through the firewall and into some type of plug that connects to i dont even know what. and after messing around with many things, the starter still wont run #2: The MSD ignition box is half useless. The specific one he got was made for a turboed car, which this one never was. So there are wires all around the pedals just dangling around, and they lead to the Retarding dial thing, and the turbo timer which i dont know if they work because we cant turn on the car to find out. Also, we found that a lot of the wires lead to nothing and there are A TON of loose ends of wire that connect to nothing all through out the engine bay. #3: The car would run, and I actually drove it around the block before buying it (2 days ago) and it sounds fine, but has a terribly hard time starting and staying running at first. The car also doesn't seem to make as much power as it should (problem #4), especially with high-compression pistons. We did find out that 1 of the cells in the battery are bad, but even with a battery jumper/charger the car wouldnt start easy. #4: I went to do a compression test (today) and this is when the starter switch decided to break, so i was unable to test the compression because the car wont turn over and we had got busy on trying to fix that. Main questions: What am i supposed to do with all these loose wires when some of the MSD box seems to actually be hooked up and other parts dont? What should i do about the switch start set up? How do i change it back to the original? Where can i buy more wires and learn how to wire it? What should i do about the turbo timers and boost retarder dial that goes through the firewall and connects to the msd box? Should i keep the msd box and how do i make sure what to do with it? What do i do about the wrapped bundle wires that you cant see what is in it? By the msd box one of the bundles of wires were unwrapped, and one of the wire's insulation is completely melted off, what should i do about it? Misc: The car also has a S-AFC II by Apexi hooked up and it works when the engine runs, how do I read and use this thing, or is it useless? Why would there be all this turbo stuff on a high compression built engine? There was also a random oil pressure gauge, not hooked up of course, shoved down in the engine bay,what am i supposed to do with it?! I have so many questions and I know i went in definitely not as prepared as i thought i was. I almost need to find someone around me to help Sorry for the overwhelming post, i just have no clue what to do with it after only 2 days of owning it. I am so overwhelmed by problems [IMG][/IMG]

01-20-2015, 10:26 PM	#2
dbeiler Zilvia Junkie Join Date: Jun 2012 Location: Lancaster county, PA Age: 33 Posts: 465 Trader Rating: (4) Feedback Score: 4 reviews	You need to find some help in the form of a local friend with some electrical experience. Option 1, you can count on your car being down for a few days while you sort through the wiring mess, returning everything to as stock as possible. Option 2, you can fix the starter wiring and drive the car, while dealing with hard starts, battery parasitic drains, ignition issues , and wiring shorts. I recommend you restore all the electrical wiring to the factory diagrams. It's much easier if you have another identical vehicle close by to "mirror"

01-22-2015, 05:41 PM	#3
Gorman240 Join Date: Aug 2012 Location: Indianapolis IN Age: 31 Posts: 28 Trader Rating: (0) Feedback Score: 0 reviews	If it were me, i would personally take the wiring harness out and all of the msd igniton & apexi controller stuff. Then i would search on the forums for an uncut factory harness that you could replace it with. Then install the new/used uncut harness. It may be the easiest option for you but it would require a lot of work. Dealing with other peoples wiring "solutions" can be a bigger pain in the butt than simply taking it all out and replacing it all. I say this because you could spend countless days tracing wiries, finding out what the previous owner did to get power to the msd coil, or power to the starter. It would be much more time efficient to gut the wiring and start over with an uncut, clean wiring that you can follow along with on a factory diagram. In the end its either figure out previous owners jigsaw puzzle, or start over from scratch. GL

01-29-2015, 09:28 PM	#4
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 41 Posts: 4,828 Trader Rating: (17) Feedback Score: 17 reviews	This is why there is a premium on a non-modified 240sx. -that is a BTM(boost timing) box and the SAFC to control larger injectors -the engine must have been on turbo at some point. -High compression puts additional wear on the starter. I recommend as others have, either go back to stock using an oem donor vehicle, or just drive the donor vehicle while you tear apart this one. Take a picture of the injectors next. Also it wouldnt hurt to pressure wash the engine bay, inspect the oil seals of the engine.