Im trying to figure out how to hook up a Zex #82015 Nitrous kit in a 92' TBI Camaro. The issues that I am having problems with is where to tap the TPS Signal, and if the kit can even be used with the stock FPR? The word from an expert is no, because the ZEX unit will try and up the fuel via the fuel pressure regulator. Can we run with this feature disconected? Much help would be appreciated!
We are trying to get this kit hooked up as soon as possible, so if you can help, please do!

 

I'm not really familiar with that kit, but on my NOS #5151 Wet Kit, the additional fuel comes by way of removal of the schrader valve and getting the extra fuel there. I'm not buying the needing an adjustable FPR to run that kit, but as I said, I'm not familiar at all with the ZEX kit.
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Mines on a TPI type system. I noticed you're TBI. Hope you get it lined out soon.

 

If the system didn't offer you a jumper plug that goes between the tps harness and the tps, then you'll have to crimp into the wires. Get a service manual. It should tell you which one is the signal wire or use a volt meter. Also if you're using a dry system, which I think a ZEX kit usually is, you need the extra fuel pressure to add more fuel for the nitrous or else BOOM! Make sure to be safe you're running stock timing and throw in a fresh set of spark plugs. No platinum cause it acts like a glow plug and it will detonate.

 

The kit was bought used, so no there is no jumper plug. We have a haynes/chiltons but no service manual and its on our lists of things to get
Which wire specifically would it be off of the TPS? Color or posistion would help. Also I know why it needs to connect to the FPR, my question more or less is will it work with a stock FPR?

 

The Hayes manual should tell you which wires for the TPS. Check "setting the TPS". As for the FPR, the ZEX kit should alter the fuel pressure via the vacuum line. I'm not exactly sure if it will work on a stock FPR, but unless you were supplied with one you should be o.k. Most kits are set up to work on bone stock cars. Test the car on the lowest HP shot. Call the tech line if you're really stuck.

 

Still looking for some help

 

Ok, need to get out of my system… why would anyone in their right mind want to run a ZEX kit….

Ok, now that I got that out, your link didn’t work so I don’t know what you’ve got there, but my guess is that you have a setup that is designed to work as a dry kit.

TPS- get a DVM, set it on VDC and you should find that one of the 3 wires will measure 5V between the wire and a ground, one will measure around 4.5 or more and drop as you open the throttle and the other will measure around .5 and go up to 4.xx as you open the throttle. The last one is the one you need there (the right one and exact values change from year to year and I don’t have a diagram for a ’91)

As far as the enrichment, if it is a dry shot that works by boosting your fuel pressure then it won’t work on your TBI, at least not as things sit. Your stock TBI regulator doesn’t have a sealed can with a vacuum fitting on it to even connect it to.

If you were ambitious and wanted to make it work you’d either have to dig up one of the vacuum referenced FPR’s that GM made (I believe they were used in marine applications) and there were a few aftermarket ones, all of them appear to run in the $80-100 range, or block off the stock regulator assembly and plumb a low pressure bypass regulator in the return line that has a vacuum fitting in it (probably easier in the long run). You will not want to actually connect the vacuum fitting to engine vacuum, but just to the ZEX box, and this is where things will get weird. You’ll probably have to run a small bleed in the vacuum line between the zex box and the regulator just to bleed off pressure when you’re not spraying, AND you’ll have to pull apart the zex box and find the restrictor in that line and replace it with a smaller one (it’s most likely designed to be used with something that uses a rail pressure in the 38-60psi range and your TBI setup uses 8-12psi, so the amount that it will try to raise your fuel pressure without restricting it down will be WAY out of line.)

Since the zex kits are designed to be plug and pray, not having to know anything about how the thing works, all this playing around with it to actually make it work effectively makes it a “it will not work,” at least not for zex’s intended market (monkeys with 10 thumbs), but it can be done…

 

THANK YOU! That is the kind of inofrmation I was looking for! And the link does work, its a PDF. The kit was sold back to the orginal owner and a shift kit is being purchased in its place. Thanks again!

 

I guess I should have phrased it differently, their site was down when I tried it... unfortunatly, the connection that i'm using now is to slow to deal with most PDF's so I can't look at it now either...

Next time, NX stuff all the way... yea, the solinoids are huge and a pain to mount but also about the most durable stuff out there and straight forward...

 

Sure thing, the ZEX kit was only bought because he got it for 100$ which was a steal.

 

Heh, for $100 I probably would have ripped the thing apart and figured out how to make it work or spent another $100 and added a fuel solenoid and made it a wet setup…