I''m looking for information on the TBI system like the one I had on an ''85 marquis brougham, 4L V6

 

what information do you need? There''s novels worth of information on TBI systems.

 

I want to adapt one to a 300 I6. What is the bolt pattern, how much fuel pressure is required, what sensors does it connect to, where is the ecu mounted, etc.

 

the bolt pattern depends on the intake on the 300. the stock intake may be a direct bolt on. Since I don''t have those specs, I couldn''t tell you. Fuel pressure for all stock carbs is usually 4-6 psi or less. Some quads used a little higher (8psi I think it was), but any 2bbl should do find with 4-6psi. The sensors should be all the same except having only one oxygen sensor. Of course the sensors will have to be for that specific engine. The sensors in the carb itself should have no issues (I think this should only be the throttle position sensor... any other electrical connections are for control, not sense). And this is if you''re using a "modern" carburetor. if you''re using an older manual/mechanical carb, you''ll just need to worry about getting all the wiring and stuff sorted for the I6. The ECU should be under the dash somewhere (varies by make/model).

If you''re swapping the I6 in place of the V6, you may have to change the wiring. Be sure to check and double check all the wiring to make sure it all goes to the right places.

If you''re just taking a carb off to put on the I6, then you''ll just need to make sure that it has the same amount of connections as the old carb. If the bolt pattern doesn''t fit, you''ll need to buy/make an adapter plate.

What make/model are the engines from. Which route are you going (engine swap or carb swap)? I might be able to find out the bolt pattern if you give me this info.

 

I''m putting the 300 into another vehicle. Have already acquired newer 2-piece exhaust manifolds, and have been looking at 2V intakes. I remember (fondly) my ''85 merc and its wonderful TBI. If I could adapt a TBI like that one to the intake of the 300, you''d have to chisel the grin off my face.


I realize I''ll have to replace the mechanical fuel pump with something that puts out more pressure, but I don''t know how much - I''m guessing 40-45psi. I''m curious about what sensors I would have to connect to the ecu for it to be able to perform all its magic functions.


I gave the mercury away, and never even had a manual for it. I''ve got somewhere between 50 & 100 chiltons and haynes laying around, but none that cover the merc.

 

Hope it is worth it cause you are looking at alot of time, money, and HEADACHES. Alot of parts are interchangable w/reasonable ease, but not what you are trying to accomplish. But if you have the resources, any custom build is possible. Good luck.

 

It probably would be a lot easier to get a dual carb setup for that 300 than trying to chisel the TBI onto it, unless you can find a year model that used the TBI carbs and get that ECU. Personally, I''d rather have a good mechanic that knows old carbs dial in a quadrajet or similar little primary/toilet flusher secondary style carb on it... or even do one of these dual quad setups:
http://www.cliffordperformance.net/

I can''t find any models that used TBIs on the I6, but I didn''t spend much time looking either. I do know that the EFI 300s in the late 80s early 90s F150s are practically indestructible, but harder to "tune for serious power" since the fuel injection systems are pretty limited to the stock setups.

replacing the mechanical fuel pump won''t be much of a headache (other than finding an ignition circuit to feed it power) since these are sold just about everywhere.

the problem is if you don''t have an ECU that is designed to control a TBI carb, you won''t have any way to trigger the opening of the jets.

 

I don''t want to spend the bucks on an aftermarket manifold for a 2V or 4V. My Brougham had a 4l displacement, and the 300 I6 has 4.9. The physical size of the Brougham''s TBI is similar to my existing 1V. If I were to scrounge a TBI from a donor Brougham, I would get the ECU that goes with it, and the flow rates should be close enough to make it work. My concern is what other sensors would have to be connected to the ECU, and can any of my existing sensors be made to work.

 

usually only the external sensors might work. anything in the engine, like knock sensor, coolant sensors, oil pressure sensor, oxygen sensors, may be engine specific. If the ECU for the TBI has inputs for all the sensors that the I6 has in it, it may just work. I wouldn't expect it to work flawlessly though. And some aftermarket ECU programming may be needed to get it at good or better efficiency. Of course, if you're good with reading oxygen sensor outputs and messing with timing, you may be able to get it running well enough to be good and reliable. Just be aware that a LOT of tweaking may be needed to match up this setup.

Basically, use the sensors designed for the I6 for the ones that are in the engine (this is important for the knock sensor, but not so much so for the coolant temp sensors since you can get various range sensors and switches that work with the coolant system). You might be able to use the oxygen sensors, but check for fit on the exhaust manifold.