I found a pic of the 85 CFI police restrictor plate

[crazyman]

I ordered '84 3.8 LTD II injectors, a new O2 sensor, and a base gasket for the plate from rock auto for $58 shipped. A buddy of mine thinks he has a lead on a used adjustable regulator. Tick-tock..

At 30k miles, it shouldn't need an O2 yet, but the car came from a congested suburb of chicago. Alot of idle time at stoplights. The plugs and wires were cooked (already replaced), so I figured at $10, an O2 would be worth it.

[fmansfield444]

I ordered '84 3.8 LTD II injectors, a new O2 sensor, and a base gasket for the plate from rock auto for $58 shipped. A buddy of mine thinks he has a lead on a used adjustable regulator. Tick-tock..

At 30k miles, it shouldn't need an O2 yet, but the car came from a congested suburb of chicago. Alot of idle time at stoplights. The plugs and wires were cooked (already replaced), so I figured at $10, an O2 would be worth it.

$10 o2 sensor?!?

Also I'm pretty sure all stock CFI fuel regulators are adjustable once that black plastic cap is removed. Mine was anyway. Unless you're talking about an aftermarket one.

[crazyman]

$10 o2 sensor?!?

Yep. The O2 has made in America stamped right into the metal (84 marq CFI).. $32 for a pair of new not reman injectors (84 LTD II 3.8), and 98 cents for a carb type gasket for the plate to seal to (75 ranchero 351). My first of many orders from rock auto.

I want the regulator to be vacuum referenced to reduce PSI during high vacuum, hence the mustang aftermarket one, while yet being able to jack up the base pressure to compensate for the 3.8 injectors.. Still looking for a used kirban or accel regulator, BTW. And a 3g should stabilize the system's inputs and outputs, as it will hold a steady voltage at any RPM/load.. As lazy as the turn signals get at a stoplight, imagine the injectors too..

[gadget73]

The sensors mostly run from a regulated 5v source, so the values shouldn't go stupid with alternator voltage fluctuations. Regulator is internal to the ECM.

[crazyman]

Mostly... Yeah, yeah, yeah... What about the fuel pump slowing down? Whatevs.. This is a project to get my grandma better mpgs.. More or less an experiment, based upon 20 years of fantasizing, fixing, and wrecking engines..

If anything, I'm the forum member that asks the least questions, but questions the most.

[crazyman]

I got paid finally from a dude storing three boats on premise.... I ordered a new kirban regulator and pumped the tank full slowly until it clicked off 5 times.. Well, full flow until the first clickoff.. Base MPG coming, as well as the last of the parts for my experiment en route...

[crazyman]

First tank to tank, 14.72 mpg's. 182 miles, 12.75 gallons. Mixed granny and me driving. I baby it. They were sold out on the Kirban. Drop shipping it.

[crazyman]

I got everything together except the new O2. Hard to get at. Jacked the pressure from 38 to 50. It's happier not being vaccuum referenced. The original reg was non adjustable. I haven't gotten new MPG's yet.

The car floats along at 55 BARELY touching the pedal, and it has TONS of throttle response and torque now. A half inch into the pedal and it feels like a modern efi car. The mileage has to be better..... Taking a 3 1/2 hour roadtrip next week with grandma. I'll fill the tank up as I enter and leave route 55 just to get a pure highway reading.

[purplebomb302]

What regulator and injectors are you running? Hows the new regulator work without the vacuum? I'm very interested in seeing what MPGs you are getting. Would you be willing to do a write-up on this? I want to keep my CFI for a while and if you're getting better throttle response out of it im very interested.

[crazyman]

Kirban adjustable stang reg. 3.8 CFI injectors. The car already has 90 + miles on the clicker. The gauge has hardly moved... No MPG's until the trip, but the car is incredibly more responsive off the line.. What more write up do you want than this thread? I can get into deflagration if you want... Who knows what mod caused what.. My guess is the plate is 45%, the smaller drops the rest, the EGR spacer mod? IDK.......

Thank you for keeping old school relevant.. If you plop 3.8 CFI injectors in, and bump the psi to 50, you will reap.

To quote my avatar pic, Red 2 is almost as funny as the original flik.... Watched it last night...

My inner gearhead says that the vacuum line should be on the bottom side of the diaphragm on most systems. Higher PSI under light throttle, bigger drops under WOT...

[crazyman]

I hafta up and down the pressure to nail it still. 50 still rocks it tho.

[gadget73]

What was the size of the old injectors vs new? I don't know quite enough about the CFI cars to know this information.

[crazyman]

Sorry PurpleBomb.. I was pretty buzzed last night. I'll do a proper write up when I figure out the injector lbs/hr and math it out to find the correct fuel pressure. It's off until the ECU goes closed loop, so I know I still need to jack with it..

[purplebomb302]

Sorry PurpleBomb.. I was pretty buzzed last night. I'll do a proper write up when I figure out the injector lbs/hr and math it out to find the correct fuel pressure. It's off until the ECU goes closed loop, so I know I still need to jack with it..

Lol no problem. I'm glad to know that there's hope for CFI.

[gadget73]

I'm just curious what the mechanism for improvement here is, maybe better atomization with higher pressure. I do sort of wonder if having a pair rebuilt and flow matched might not do some good too.