Close



Results 1 to 15 of 15
  1. #1
    New User
    Join Date
    Oct 2018
    Location
    Chippewa falls wi
    Posts
    25

    Default 85gt fast idle help needed

    Looking for a CFI GURU if any exist or any in here. Having a fast idle issue on my 85gt.
    I located the parts to hook it all back up and i can set the fast idle with pumping the gas BUT it wont release.
    I can manually pull vacuum on the actuator and itll pull in so the diaphragm is good. BUT the car wont release it and i cant make the rod stay in contact with the lever.

  2. #2
    FEP Power Member
    Join Date
    Nov 2007
    Location
    San Mateo, CA
    Posts
    2,271

    Default

    Quote Originally Posted by 85gtfox View Post
    Looking for a CFI GURU if any exist or any in here. Having a fast idle issue on my 85gt.
    I located the parts to hook it all back up and i can set the fast idle with pumping the gas BUT it wont release.
    I can manually pull vacuum on the actuator and itll pull in so the diaphragm is good. BUT the car wont release it and i cant make the rod stay in contact with the lever.
    If I remember correctly, the fast idle cam is very much like the automatic choke set up. Take the choke cover off and make sure the coiled spring is intact and that it is aligned in the center of the fork. I believe the setting is at +1 on the scribe marks. It should move freely with the cap off. Next make sure you have voltage to the choke cap with the engine running. It should heat up and move the coil spring. That’s the basics and should get you started.

    Mine tends to stick when not started in a while.
    Fox Body/3rd Gen MCA Gold Card Judge
    84 SVO 24K miles, 85 Mclaren Capri Vert. 84 GT Turbo Vert.
    88 Mclaren Mustang Vert 20K miles, 89 Mustang LX Sport Vert,
    03 Mach 1 7900 miles, 74 Mustang II, 69 Mustang, 67 Mustang, 07 GT500,
    14 Mustang CS/GT, 15 F150 FTX Tuscany, 16 F250 Crewcab, 67 Tbird 47K miles

  3. #3
    New User
    Join Date
    Oct 2018
    Location
    Chippewa falls wi
    Posts
    25

    Default

    I have voltage and the spring is springy. Im not 100% sure im assembling correctly since they were missing when i got the car. If i give the throttle a snap everything pops into place and the car will fore on high idle but the rod in the vacuum actuator thing just sits there. Not sure how long it takes to come off high idle but im still having to drive her and cant if i cant figure this out

  4. #4

    Default

    Is this at the 1500 idle or the next step? There are two stages to the bumped up idle.
    1984.5 G.T.350 5.0 CFI AOD Convertible (TRX package, loaded)
    K&N filter in a stock dual snorkel, GT40 heads, Edelbrock 3721 intake, MSD 8456 Dist., MSD 8227 coil
    Comp cams XE254H, hypereutectic pistons
    Hooker Super Comp Shorty Equal Length Headers, catted BBK H-pipe, full custom duals
    Maximum Motorsports caster/camber plates and strut tower brace, 3.73 rear, dura grip (both Yukon)
    Ford Performance Springs, Firehawk A/S 225/55r16 on LMR TRX r390 wheels (street)
    Federal 595 rs-rr 245/40r17 and 255/40r17 on OE cobra r wheels (race)
    AOD rebuilt with a 6 clutch direct drum, Koline steels stacked with 8 clutches, Kevlar band, superior shift kit, new torque converter. --Everything else stock and fully functional.

  5. #5
    FEP Power Member
    Join Date
    Nov 2007
    Location
    San Mateo, CA
    Posts
    2,271

    Default

    The cfi is a little different from a carb. choke with the timing of things. Ten minutes of idle should be enough for it to slow the idle some. Driving seems to kick it down faster. Idle is about 800 while in drive.
    Fox Body/3rd Gen MCA Gold Card Judge
    84 SVO 24K miles, 85 Mclaren Capri Vert. 84 GT Turbo Vert.
    88 Mclaren Mustang Vert 20K miles, 89 Mustang LX Sport Vert,
    03 Mach 1 7900 miles, 74 Mustang II, 69 Mustang, 67 Mustang, 07 GT500,
    14 Mustang CS/GT, 15 F150 FTX Tuscany, 16 F250 Crewcab, 67 Tbird 47K miles

  6. #6
    New User
    Join Date
    Oct 2018
    Location
    Chippewa falls wi
    Posts
    25

    Default

    I did not notice which knotch it was on. Debating on going back out and messing with it some more today.
    Ok kevinK, ill give if some time and see what happens.

  7. #7

    Default

    Depending on how you have the fast idle screw set the initial cold idle should be 1500 to 1800 and should last 30 seconds or so. That will then kick off to the lower 1100 to 1200 rpn setting. In drive you will see about 900 or so, even 800 at that point. This is where it gets tricky. That mechanical increase goes away rather quick but the computer will keep your idle up there with advance until the engine warms enough. When that happens it should drop down to 550 in drive, 800ish in park or neutral.
    1984.5 G.T.350 5.0 CFI AOD Convertible (TRX package, loaded)
    K&N filter in a stock dual snorkel, GT40 heads, Edelbrock 3721 intake, MSD 8456 Dist., MSD 8227 coil
    Comp cams XE254H, hypereutectic pistons
    Hooker Super Comp Shorty Equal Length Headers, catted BBK H-pipe, full custom duals
    Maximum Motorsports caster/camber plates and strut tower brace, 3.73 rear, dura grip (both Yukon)
    Ford Performance Springs, Firehawk A/S 225/55r16 on LMR TRX r390 wheels (street)
    Federal 595 rs-rr 245/40r17 and 255/40r17 on OE cobra r wheels (race)
    AOD rebuilt with a 6 clutch direct drum, Koline steels stacked with 8 clutches, Kevlar band, superior shift kit, new torque converter. --Everything else stock and fully functional.

  8. #8
    New User
    Join Date
    Oct 2018
    Location
    Chippewa falls wi
    Posts
    25

    Default

    After 15min of idle it was still at 1500-1800ish. I still have the factory tach and pretty sure it’s inaccurate. The only time it fell off high idle is when I manually flipped it off but as soon as i give ot gas everything resets and its on high idle again.
    I havent adjusted or messed with anything other than installing the parts to hook the shaft at the tps up to the rest.
    Does all that stay engaged all the time? All this was disconnected when i got the car. Just doesnt make any sense to me that its always going to be engaged and idle high

  9. #9
    New User
    Join Date
    Oct 2018
    Location
    Chippewa falls wi
    Posts
    25

    Default

    I took video of the fire up and after 15min but i have 0 clue how to post them on here from my iphone

  10. #10

    Default

    You need to put it on YouTube first. This sounds like an adjustment issue. The spring is not moving the catch far enough to stop the high idle cam from engaging. My first guess is that spring isn't doing its job, whether that means it just needs to be turned a bit or replaced or the wire isn't connected properly, I don't know. I can try to track down a picture if you like.
    1984.5 G.T.350 5.0 CFI AOD Convertible (TRX package, loaded)
    K&N filter in a stock dual snorkel, GT40 heads, Edelbrock 3721 intake, MSD 8456 Dist., MSD 8227 coil
    Comp cams XE254H, hypereutectic pistons
    Hooker Super Comp Shorty Equal Length Headers, catted BBK H-pipe, full custom duals
    Maximum Motorsports caster/camber plates and strut tower brace, 3.73 rear, dura grip (both Yukon)
    Ford Performance Springs, Firehawk A/S 225/55r16 on LMR TRX r390 wheels (street)
    Federal 595 rs-rr 245/40r17 and 255/40r17 on OE cobra r wheels (race)
    AOD rebuilt with a 6 clutch direct drum, Koline steels stacked with 8 clutches, Kevlar band, superior shift kit, new torque converter. --Everything else stock and fully functional.

  11. #11
    New User
    Join Date
    Oct 2018
    Location
    Chippewa falls wi
    Posts
    25

    Default

    So the spring is what controls the high idle cam to take it off? What is the little hook shaped rod for that does nothing? I never tried adjusting anything just installed it the way it cam from a guy on one of the facebook groups. The little spring that goes on the shaft theu the tps i cant figure out either.
    A pic woukd be helpful. Ill try to upload to the laptop and try to post them videos here using that.

  12. #12

    Default

    Yeah, the spring moves the cam out of the way when it warms up. The little hook is the pull off from fast idle if I remember correctly. I can't remember if the votm kicks it up or if that pulls it back. I think it does pull it back. Maybe both. Can't remember about the spring. I have an extra one laying in the garage I could look at though.
    1984.5 G.T.350 5.0 CFI AOD Convertible (TRX package, loaded)
    K&N filter in a stock dual snorkel, GT40 heads, Edelbrock 3721 intake, MSD 8456 Dist., MSD 8227 coil
    Comp cams XE254H, hypereutectic pistons
    Hooker Super Comp Shorty Equal Length Headers, catted BBK H-pipe, full custom duals
    Maximum Motorsports caster/camber plates and strut tower brace, 3.73 rear, dura grip (both Yukon)
    Ford Performance Springs, Firehawk A/S 225/55r16 on LMR TRX r390 wheels (street)
    Federal 595 rs-rr 245/40r17 and 255/40r17 on OE cobra r wheels (race)
    AOD rebuilt with a 6 clutch direct drum, Koline steels stacked with 8 clutches, Kevlar band, superior shift kit, new torque converter. --Everything else stock and fully functional.

  13. #13
    New User
    Join Date
    Oct 2018
    Location
    Chippewa falls wi
    Posts
    25

    Default

    Aight. Any way to test that or should i just look for a replacement and hope it works? Vacuum diagram shows the one with the hook and the one at the trottle are tied together but on the car they arent and it all looks to still be in factory locations so those 2 really have me stumped as to theor purpose since neither seems to function.

  14. #14

    Default

    The votm, the one on the driver's side doesn't do much most of the time. It just kicks it up when the a/c is running. The one on the passenger side just does the one job. I can take some pictures for you tomorrow. If I were you I would try adjusting the spring by loosening the hold down plate and spinning that bit with the big spring in it.
    1984.5 G.T.350 5.0 CFI AOD Convertible (TRX package, loaded)
    K&N filter in a stock dual snorkel, GT40 heads, Edelbrock 3721 intake, MSD 8456 Dist., MSD 8227 coil
    Comp cams XE254H, hypereutectic pistons
    Hooker Super Comp Shorty Equal Length Headers, catted BBK H-pipe, full custom duals
    Maximum Motorsports caster/camber plates and strut tower brace, 3.73 rear, dura grip (both Yukon)
    Ford Performance Springs, Firehawk A/S 225/55r16 on LMR TRX r390 wheels (street)
    Federal 595 rs-rr 245/40r17 and 255/40r17 on OE cobra r wheels (race)
    AOD rebuilt with a 6 clutch direct drum, Koline steels stacked with 8 clutches, Kevlar band, superior shift kit, new torque converter. --Everything else stock and fully functional.

  15. #15
    New User
    Join Date
    Oct 2018
    Location
    Chippewa falls wi
    Posts
    25

    Default

    Ahhhhh. The “choke” itself? Yeah i think thats one of my next steps along with cleaning up the electrical connector and probably replace the brittle connector as well.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •