I know I have asked many questions on this before but someone online said that you really dont need the ACT sensor hooked up right away when you do the LA3 swap. Now is he right or wrong because these bigger injectors are hurting my gas mileage and I need the computer that can supply them. One more thing, on the 84 and early 85 SVO's, do you unplug the motorcraft box that has the boost control solenoid on it or is that for manual valves only, thanks?
Swap in process
- Thread starter SVOconvLX85
- Start date
mr_woodster
Active Member
Gonna need some more details about your car, swap info and the little deals. What is your setup now?
Depending on WHAT harness your talking about, you need to repin for the la3. Yes, you can get away without an ACT sensor, but i ask why? Installing it would take you so little time (depending on vehicle). Basicly what is your setup...we shall go from there
Depending on WHAT harness your talking about, you need to repin for the la3. Yes, you can get away without an ACT sensor, but i ask why? Installing it would take you so little time (depending on vehicle). Basicly what is your setup...we shall go from there
I think it's an '85 conv LX.
Yeah, you can run w/o the ACT on an ACT equipped computer. Yes, you'll get way better gas mileage with it. I've got a bud not running an ACT he gets around 22, I get just over 30.
Yes, with the later computer's like the LA, LB's you'll unplug the motorcraft unit that controls the boost - but leave the sensor/solenoid thing in there that the vacuum lines attach to. Still better, put in an Adjustable boost valve like this: http://www.boostvalve.com/pricelist.html and then you don't rely on the computer for boost control and can add several pounds more boost.
Yeah, you can run w/o the ACT on an ACT equipped computer. Yes, you'll get way better gas mileage with it. I've got a bud not running an ACT he gets around 22, I get just over 30.
Yes, with the later computer's like the LA, LB's you'll unplug the motorcraft unit that controls the boost - but leave the sensor/solenoid thing in there that the vacuum lines attach to. Still better, put in an Adjustable boost valve like this: http://www.boostvalve.com/pricelist.html and then you don't rely on the computer for boost control and can add several pounds more boost.
Well, its an '87 conv. with '85 SVO motor and everything else that came on the SVO. It has the PJ computer and someone that had it before me put 35 pound injectors in it and it loads up too much when I get on the gas. So I picked up an LA3 from the junkyard and I have an ACT sensor and wiring from my '87 lower intake but it wont have a place in the motor because the square style intake that I have is polished from an '86 turbo coupe so it didnt have the threads for the sensor. Next, it will go into place when I get my fmic hooked up and make a spot in the tubing for it. I just wanted to know if it would effect performance but for now I just want the computer for the injectors.
I was thinking and it seems that if I disconnect the Motorcraft box that has the solenoid wires in it, then how will the solenoid work if the wires are disconnected. Where does the purple wire for boost control on the computer go to. Even if the LA3 has the same function as the Motorcraft box built into it, then I should have to reroute the solenoid's wires somewhere else, shouldn't I? I just dont want an adjustable valve yet, I want to get the computer in the car and have it running good.
I've got my ACT hanging in the bay since I ported the TC lower intake and not the Mustang lower intake, which has a spot for the sensor.
Well, the swap is done, at least it was. I switched every wire and added a wire for my ACT sensor and unplugged the Motorcraft box and took it for a drive. It was fine until I shifted and I had no Boost control. Whoever said that you can unhook the box and still have the stock configuration isn't right. So I was thinking about the Turbocoupe diagram and I didn't switch thepurple boost wire to its new spot. I added a wire like it had in the diagram and I took care of the other wire too. So I had a wired in boost solenoid to the computer. Thats when I could hear the boost hitting the throttle blade. Thats what it sounded like at least. So, now I need to know where that purple wire for the boost control goes to. It doesn't go through the firewall right away. It looks like it ties into the pre,ium switch somehow. Is that Motorcraft box the rev limiter? How can I complete my swap and have the stock boost controller for now? I had to undo the swap and put my old computer back in.
