TBI Install '75 Scout II 304 Manual

[Dkminors]

I finally got my install off the ground and running. Thank you Bill and everyone else for all your great information and insight which made this possible for me.

Things went pretty well overall, but I wasn't in a rush so I read and re-read the materials quite a bit.

I used a 1228746 ECU off a 1989 Camaro (5 liter with manual trans). One of the problems I had was that I didn't acknowledge the Vehicle Anti-Theft System and it's consequences. Due to this my initial cranking was just that (with no ground provided to my injectors). Once I figured that out I purchased a Painless VATS defeat to send the appropriate signal to the system allowing a ground for the injectors. I actually put together a unit on a bread board that worked fine (all of $5 in parts), but my soldering skills weren't up to the challenge hence the Painless unit.

Another thing I did was grind down the intake a bit to smooth the transition to the TBI adapter plate.

You can also see where I put the harness through the firewall. The grommet I used was a 2 in. I harvested off a '75 Ford pickup. I like this spot because I think I can store the ECU on top of the heater duct. Not sure whether or not it will be too hot there.

Anyway, I did my initial pre-startup procedures and voltage readings and everything seemed fine. I was a bit baffled by the variation in idle speed as well as the feeling that I had a rev limiter on the system. I convinced myself that part of the issue was related to the Knock Sensor which I now have disconnected with good results.

I am attaching a data log prior to disconnecting the KS.

I'll need to log more now that it's disconnected.

The system has the IAT, EGR, O2, VSS, Oil Pressure Switch, and Purge Canister on the system as well as the other standard sensors.

Before I installed the TB I sent the injectors over to Witch Hunter for cleaning and testing. I didn't know anything about the condition of those and figured the cost would be worth the certainty it would provide.

[scorp1us]

I would have just checked the injectors with a timing light.

It could be that you're hitting a timing limitation. My ride will actually accelerate at times when I back off on the gas. I just got a prom burner...

[Tom Mandera]

That looks to be about the same spot I ran mine through the firewall.

I just put a new gas filler gasket/grommet on the quarter panel of my '79, and seeing my other harness and your picture, I'm thinking that the good old IH filler hose gasket is a good source for the jumbo grommet we need for the TBI pass-through.

My TBI system had a 2x2 square for the firewall pass through, so I cut a 2x2 hole and then used a couple of short straps of 1/8" flat to pinch it to the firewall. So far so good.

I believe you could have disabled VATS using a program change in the ECU.

The Camaro has a VSS based top-speed limiter, which can be reprogrammed to be an RPM limiter, but out of the box it's based on the VSS.