Buick 3.8 MPFI conversion

[dave w]

Ok this becomes my recipe.

1. EVERYTHING includes items available when I pop the hood in a junkyard or do I have to get underneath the car? I do not need the intake manifold? How do I identify the 4.3 if radiator support sticker is not intact? Do I have to tear apart dash to get to computer?

You will have to do some homework to figure out how to identify a 4.3 liter engine in a salvage yard. The 4.3 intake will not fit the 3.8, leave the 4.3 intake at the salvage yard. For most 4.3 vehicles the computer is behind the glove box. You will need to do some additional homework to learn and identify the necessary TBI sensors and their locations to know if you will need to get underneath the donor vehicle to get the parts you need. There is also the option of buying new sensors and new TBI parts and skip the salvage yard trip all together.

2. If I am fabricating an adaptor plate this means I can choose intake manifolds to adapt to, I have a Kenne Bell single plane that fits. Is there a manifold characteristic that I should be looking for? maybe just take the 4.3?

The Kenne Bell intake swap is a good plan.

3. Will look for that distributor ... what is the reason the remote coil distributor is necessary? Just curious.

You will need to use the 85 Electra distributor, leave the 4.3 distributor at the salvage yard.

4. Harness simplification ... what is standing alone? Computer not adjusting spark advance?

Simplify the harness means, all unnecessary wiring is removed or terminated, setup with a simple 4 wire hookup (Battery +, Battery -, Ignition On/Start, and Start ONLY).

5. Understand o2 sensor ... car will need exhaust anyway ... is there a reason sensors are not placed in exhaust manifolds rather than downstream? Normally 2 ahead of and beyond cat to verify its working as well as adjust fuel delivery .. right?. This one will just be adjusting fuel delivery only. Was hoping the exhaust would be a Walker bolt on affair but they have possibly trashed the H-body info if they ever had it, I cant find. Not done looking. Having trouble getting the smaller ext balanced flywheel and clutch as well.

The 1227747 uses one O2 sensor mounted in the exhaust manifold. There is the option of using a 3 wire O2 sensor mounted in the exhaust "Y" pipe. It's never been easy to find a Buick 3.8 flywheel because almost all Buick vehicles are automatic.

6. The reason an electric fuel pump is required ? The fuel must be delivered to the tbi at higher pressure than mechanical devices?? Finding a tank to fit Sunbird wagon may not be cake.

TBI fuel delivery systems operate in the 12psi ~ 15psi range with a return line to the gas tank. There are aftermarket inline and in-tank fuel pumps, the universal fit kind that can be fabricated to fit most any vehicle application.

7. Can you recommend chip burn resources? What would happen or not using the original 122747 or a HP shelf counterpart?

I do my own chip burning, if / when you get ready for a chip send me a PM, we can figure out a chip plan if you have not figured something out by then.

dave w

[Keithnh]

4.3L is a Chevrolet engine correct? ... this is what I need to cannibalize right? I see the 85 Electra came with Olds 4.3L diesel ... this would not have a distributor ... Im looking for an 85 Electra 3.8 distributor. Ebay does not seem to differentiate them from other years including 84 Cutlass ?? Characteristic Im looking for is a separate coil with 8-pin module correct?. Would this make the distributor cap diameter smaller like pre-hei?

Can find the Firebird with Buick V6 ext balance flywheel FW509-57$, H-body has smaller diameter flywheel, clutch + ext balance, the 3.8 Buick was standard for my application in Sunbird Safari I believe. I always seem to pick needle in haystack projects :)

Enough questions for now Im back to work after my wk-end, thanks for patience Keith

[dave w]

Yes, the TBI 4.3 is a Chevy engine.

Good job figuring out the Buick Flywheel options.

I use Rock Auto for online parts shopping, see attached screen shot for 1985 Buick Electra 3.8 distributors available @ rockauto.com. I think the Buick Electra distributor with the ignition coil in the cap is a good plan.

[Keithnh]

Looks like I may be searching for an 85-95 RPO LB4 TBI 4.3 that may have come in Caprice, Monte Carlo, El Camino, Parisienne or GP. Believe this will have the correct computer 1227747 .. now to see if that is a letter designation in the vin I can see through windshield.

The Buick Electra distributor comes from a different family fuel injection .. MPFI, correct?, not sure how it is different still, this would be an early MPFI system probably easy to spot. May be cheaper for me to just find a rust bucket and scrap the car after taking what I need, shame I couldn't get both systems in one car. Sometimes come out with the parts and $ to boot. A policy not too uncommon for me but I have trouble scrapping the cars after much to my neighbors chagrin :) They don't mind really. Luckily I live in a red-necky area :) My buddy with shop is in a dry spell right now if I can get him the 2 cars he can make a few bucks from me, strip what I need, anything else he can use and scrap.

Just saw the FW509 price jump from 57$ to 118$ overnight @ Phoenix friction ... thats weird, their tech is working my flywheel application issue today tho .. wasn't familiar with their site and hadn't found the application notes, when I did I found FW509 flywheel is for 95-02 V6 231 VIN K. Not sure what this means ... my case is one of what works, what fits and what will keep engine balanced properly. NOT what was the original necessarily. Did find FW131 that shows fitting 78-81 V6 231 Firebird .. it is 88$. It shows fitting V-8s too ?? wondered about ext balance issue?

[1project2many]

86 - 91 K1500, 2500
87 - 92 G1500, 2500
90 - 91 S/T 10

Try "1227747" on Evilbay.