I just received my chip and I had it programmed for no 9th injector because I am going to put on SLP runners without the hole for it. Can I just put the chip in and leave the injector alone until I put the runners on or do I have to unplug the harness for it?

 

ok I put my chip in and when I start the car the idle jumps up really fast and comes back down really fast. The idle overall is a little bit higher except when I hit the gas there is a loud rattling sound. I don't know if this has anything to do with the chip. I didn't even touch the injector yet. I hope it doesn't wreck anything.

 

Disconnect the harness, otherwise (assuming the chip is burned correctly) you'll be too rich at start up.

 

Ok car runs fine. Where can I get a cap to screw on to the end of the fuel rail when I pull the 9th injector? I am looking to do this pretty soon. Can I get it at a local Hardware store?

 

Anyone?

 

I've got the caps to go over the end of the fuel rail. I get $10 shipped. If you want one, email me at jim85iroc@yahoo.com.

 

I am not exactly sure what your trying to accomplish, but I just left the 9th injector in the intake, as a plug...

John

 

I originally bought SLP runners which didn't have the plug for the CSI. I didn't know that at the time, but I got them for an excellent deal. I alleady had the chip burnt for no 9th injector so all I need to do is cap off the fuel rail. I would rather do something easier like make a trip to home depot or something but I am not sure if they have that size or not.

 

The proper size cap seems to be impossible to find. Nobody on the Corvette forum could find them except as part of an overpriced kit that they didn't need most of the parts of, so when I found some, I bought a pile of them to sell to those who need them. I can't really make enough money on them for it to be worth anything, but I bought a pile anyway because I know that they are hard to find.

I can't remember the thread size, but if you want to try and find some on your own, unscrew the whole fitting in the back of your rail and bring it with you to the hardware store.

Here's a pic of the back of my rail without the cap:


Here it is with the cap:

 

Hey Jim how safe is that cap? Has anyone ever had any leakage out of it or any problems getting it to seal?

 

Mine hasn't leaked yet, and nobody that I sold them to has responded with any complaints, so they either all died in the fire, or haven't had any problems.

I used a little teflon paste on the threads, tightened it down and so far so good. I also found a plug locally that was the right thread to plug the hole in the back of the rail (instead of using the stock adapter fitting and this cap), but because it's not a pipe thread, it's not going to be self tightening and I didn't really like the idea of it. The stock insert that I'm still using has an o-ring to seal, so all I had to deal with was the seal around this cap. Like I said... so far it's been bone dry.

 

What is the 9th injector used for? Does it run any better without it?

 

On the 85-88 TPI cars, GM used a cold start injector (that's what we're calling the 9th injector), and like the name implies, it more or less just provides more fuel for when you start the car. In 89 GM smartened up and realized that it's a lot simpler to just fatten the pulse width of the other 8 injectors instead of screwing around with the 9th one. For those of us that either buy certain aftermarket parts, or just want to run the newer PROM codes, our best option is to eliminate this 9th injector.

 

Some1 told me if u buy a newer non 9th injector runners and have the older plenum and intake it wont match up is that true?? Cause i am goin to switch my maf intake i got to speed density. So could i just buy the newer runners when i get them and not worry about plugging it and still match up fine.thanx

 

I have an extrea set up from an 89, and a set up from an 87 that I am running on my car, and to tell you the truth I cannot tell the difference in the two. The ONLY major difference I can see is the 87's have an extra tube for the EGR, and the 9th injector. Never tried to bolt them up, but I would be surprised if the 89's did not fit.

John