Finally getting started

[CorvairGeek]

I had to see how long ago I introduced myself, it has been a while;

http://www.gearhead-efi.com/Fuel-Inj...3774#post13774

Got myself busy with a lot in between time, two back surgeries, shingles (x2), ischemic colitis (x2). Decided it would be cool to do some Delco/Delphi stereo mods and retrofit of a body control system (serial bus, '05 LeSabre, my avatar) and stereo for the Caprice too. That was a lot of fun!

Finally getting around to building my TBI system for my 292 L6.

Got the Offenhauser manifold and a throttle body.







In case that unit looks small, it is. This is the 2.8/3.1 V6 unit. With the original 1bbl being only rated at 250 CFM, I think the smaller unit is more appropriate for a stock 292. I will be running V8 injectors.

Got a free harness, and then some, from a great guy that had saved too much from parting a '93 Suburban.



Got everything stripped out and got it to this point. This is where I reconnected the diagnostic terminal to the PCM harness after separating it from the cross-vehicle harness.



The 'finished' product, ready for a test fit.



A close up of the speed sensor (VSS) wiring (top left, 2K Dodge speed sensor, speedometer cable driven), and the GMT 400 terminal block. A cable will come up from the starter to power the terminal block just like it did origionally. The computer is powered and protected by a fusible link, while the injectors and fuel pump relay are on their own fuses. I added these for troubleshooting. Appears this was from a '7625 PCM



Close up of the diagnostic terminal. The wire to the brake switch and the Service Engine Soon light are sticking out of the harness for connection inside the truck.



Close up of the injector connections, sensor and ground connections. I've got to change the distributor connector (bottom) from the small HEI to the large HEI connector. I may need to lengthen this part of the harness at the same time.



I intend to run a '7427 PCM. I heeded the collective advice to bypass the old '7747. Always open to more learned advice in other areas.

My big decision will be whether to go TunerPro RT or TunerCat. I'm going to have to place a order with Moates soon.

[dave w]

I would recommend using a V6 Memcal on the 292 when using the '7427.

I use both TunerPro and TunerCats to edit .bin files with. I usually favor TunerPro for the '7427, except $8C and $8CA definitions I use TunerCats.

dave w

[Fast355]

I would keep a close watch on the MAP values at higher RPM. TBI units should be sized to give as little vacuum at WOT as possible considering they are not like a carb which requires a strong signal to the venturi to pull fuel and atomize fuel. IMO, too big is just enough when it comes to a TBI. A 390 cfm or Q-Jet 4bbl on an inline 6 generally give a nice power gain. You might find with 292 CID a SBC TBI unit is more appropriate and they are dirt cheap at the salvage yards I frequent.

[CorvairGeek]

I very much appreciate the input.
I do already have a 4.3 TBI Memcal from a '7395. I expected these would be easier to find than what they have been.
I am more than willing to go to the larger TBI unit as well. It seems undersized in my mind at times, for such a big 6. This smaller unit was actually harder to find (age and less common at this point). I can get the V8 units readily. I have some fantastic U Pull It yards here.