For the 3.4 swap, you will need the following:
1. A 3.4 short block from a salvaged 92-95 camaro or firebird. (I pulled one from a Firebird. Suggestion, if you find one in a scrap yard, then take a battery and a compression tester. Using some jumper cables to get at the starter in case there isn't a key, you will want to check the compression of that block before you waste the time pulling it.) Or, you can look for someone parting out one on craigslist and go from there.
2. Once you get the engine block, you will need to use the following on the 3.4 from your 2.8:
- Timing cover, water pump, oil pump and oil pan.
- You will be using the flexplate from the 3.4, so you need the starter for that also.
3. That is all I can think of from the block since you stated that you wanted to go tbi.
On the TBI stuff,
1. Get the TBI sytem from any of the 2.8l s10's that has TBI and the following:
- The intake, throttle body, and associated brackets and cables.
- The distributor, ESC module, knock sensor, relays, and map sensor, (pretty much everything that the ECM harness connects to, you want to take)
- The ECM, BUT, if the ECM is a 1228062, then MORE IMPORTANTLY, ALSO, GRAB an ECM with the number 1227747. Will explain shortly.
- The complete harness. The best way to do that is to unhook everything, then pull the harness through the firewall from inside the cab. Be careful about the connectors.
- The VSS. This is a module in in the dash, under the instrument cluster. There is a sensor that plugs into the back of the speedo. The module will either be a yellow or green rectangular box. This sensor sends pulses to the ECM.
- Find an Astrovan with the 4.3 throttle body and grab the injectors. You can grab the throttle body if you want, but the throttle assembly might be different. I know that if you use the 4.3 throttle body, you will have to have the 2.8 intake bored out to accomodate the larger bores of the throttle body and the butterflies. (personally, I like the low end of the 2.8 throttle body, and the real gains to that larger throttle body is in the high rpm's. I want a truck that runs, not one for race)
- MAKE SURE YOU EITHER GRAB the emmisions label of the vehicle you are pulling the TBI system from, or, make sure you note the base timing listed. The 3.4 base timing must match because the ECM software has this number programmed into it.
- You are also going to need an electric fuel pump that runs at least 13 psi. I will provide the part number of the fuel pump that I am running. It's max is 22 psi, but is regulated down to 13.5 via the fuel pressure regulator in the throttle body injector pod.
- I'd recommend replaceing all the throttle body gaskets at the time you replace the 2.8 injectors with the 4.3l injectors. I bought the 305 tbi rebuild kit and then the throttle body base gasket seperately. If I recall correctly, the 2.8 kit was about $20 more than the 305 and the seperate gasket.....(who kmows.....)
In regards to the 1227747 ECM. The reason I suggest that is because that ECM has more software support than the 8062. The nice thing about the 7747 also is that the pinout of the ECM is the same as the 8062, so no rewiring of anything is required. I STRONGLY recommend the following due to the support for the ECM, (even though Jimmykicker is still using the 1228062 ECM
Next up is going to a site called www.gearhead-efi.com
and reading up. They have a forum specifically dedicated to GM OBD1 and data for wiring and programming. There, you can also find the wiring diagrams you are going to need along with info on what BIN file parameters you can modify.
If the 2.8 system you pull has the 1228062 ECM, note that the software in that ECM is written for the 2.8 engine. To put it simply, the 2.8 tbi system on the 3.4 engine, it will run leaner than it should and the programming in the ECM can only correct so much for the larger displacement, so there will be parameters in the BIN file that will ultimately have to be changed.
If you are willing to learn it, there is an awesome program called TunerPro Rt that you can run on a laptop and monitor the data stream from the ECM during normal driving. When you are at that point, there are quite a few fellas on that site that would happily help you interpret the data and advise you on what parameters would need to be changed in the programming to get the best tune on your engine.
That's all I have for the time being. I do have links posted here that goes to good info about the TBI system. You can search my posts and find these.