[Pampered-Z]

I'm up in the mountain this week taking some vacation. Um, plan was to work on the Z this week to get ready for the race season, but all I've sone so far was look at the snow falling and not go freeze my butt off in the garage! URGGGG,,,,,

I'll be back in Ewing next week if you need a hand.

Anyway, been a long time since I played with a TPI 3rd gen, But I think the fuel pump should come on with the key, Could be a few things, ECM, pump relay, wiring, And I think the distributor wiring play a part as well. The pump will turn off if the car doesn't start right away as well. I would start by looking at the relays. Get a Fuel pressure gauge too, could be the regulator is going bad and it just takes time to build pressure?

The ATI secondard pump to boost pressure, is still turned on/off with the stock one as it just plugs into the stock pump harness. Once you figure out, you should be fine. But if you want, you could dump the two, but in my option a 305 isn't going to make that much power that fuel pressure isn't going to be you problem. I would think a 305 could go 400-425 HP max, the stock and auz pump can handle that.

But fot the record. A Racetronic single pump Kit, 255 pump and harness will support about 550HP. The dual pump about 850HP, that about the limits the stock fuel lines and fuel rails can handle. This is the basic 255 walbro with a harness that draws power right from the alternator, so the 14 volts boost the pumps output slightly. Your not going to ne near either of those numbers.

You have to look at boost two ways as far as what is needed once you go to a certain piont. 6-7 PSI is the line where once you go over it you need to do more to support it. Sounds like you have a kit that was originally a lower boost set-up that has just 12 PSI pullies. you really need more that just pullies to run that boost.

12PSI pullies will probably kill the engine quickly, 6-7PSI is about all they can tolerate for an extended time. But you can get away with 6-7PSI with stock programming and an FMU. The FMU is just a cheap fix, reprogramming would be better, making the EMC read boost is best. You don't need an aftermarket EMC. Yes aftermarket is better and they have many other benefits, but a stocker will work.

You can do away with the FMU using the stock EMC but you will need to go with larger injectors and switch to a 2 bar map. For a 305 with 8-12 LBs of boost I'll estimate 350HP. Putting that into the formula you should be about to go 80% duty cycles on 24lb injecotrs ( which happens to be what stock 94-97 LT1 use! so you should be able to finf injectors cheap!) If you make above 375, which I don't think a 305 will, then you would need larger injectors.

When you switch to a 2-BAR map sensor in order for the ECM to be programmed to read boost. You just have to make sure the person doing the tuning knows what he's doing! Once you start switching Map sensors and injectors the programming gets complicated.

Question, you didn't mention any cooler? about 7PSI is the max you want to go without an intercooler of some type, your going to be building allot of heat! So think intercooler or checmical cooler such as alki injection, That plus stock high compression you need high octane. If you plan on making allor of boost you need an intercooler and also need to pull allot of timing out of you'll kill the engine quickly. Stock pistons don't last long.

As you make more boost ( above 7-8 PSI) you need to pull timing out, about 1.5 - 2 degrees for every PSI over 6. So with you high compression ( another above 9.5 static and boost is high ) and your talking boost near the double digits I would guess at least 2 degrees. You can do thing either with tuning, or something like an MSD A6LB that can read boost and pull timing.

So If you want to go with lots of boost, get the fuel pump figured out, get a 2-Bar Map ( Autoparts store, you want a map for a Grand National, then you need to cut slots in it so that it fits the stock wireharness ), get bigger injectors and get programmed.

Another key thing to remember with a SC is NOT TO OVER SPIN IT! more RPMs makes more boost by puts the SC near it's limit where it will self-destruct. About 6500 RPMs is about the limit. Most that have tried to pust them to 6700 have ended up blowing the SC to pieces and taking out their engine.!

JB