Hey i just bought my 93 FD a few weeks ago and it ran great until i got the low end idle bouncing. It runs fine as soon as you rev it up and it drives fine, but stoplights sucked real bad. it wouldnt stall, just bounce really low. After reading countless and numerous Idle threads i decided id just set my idle up a little and that worked fine. I used the vertical Screw that opens the Butterfly valves a little bit and not the bleed air screw.

Now this solved my problem and the car runs and drives great(i have the idle set at around 1000-1100 RPM) but after reading some post it sounds like adjusting the vertical screw is not the way to go as it can mess up your lower TPS readings and such. Is it bad to use the vertical screw and should i be correcting this before it gives me major problems, or is it fine to do? Any help would be appreciated. Thx.

1993 FD with a 13B eng
-Racing Beat 4" stainless 'cat-back' perf exhaust
-APEXi Blow-off
-Heavy duty ignition and Wires
-Upg dual high flow fuel pumps
-Custom cold air intake

 

bump? sumone must know the answer to this

 

I had a hell of a time adjusting my idle/TB at one point too.

You're supposed to leave those set screws alone. Try and turn the back to where they were. They should have paint marks on them or marks from where the nut rested, etc.

They way you adjust idle is by the air bleed screw located underneath the TB to intercooler elbow. It's in a odd spot, kind of back between the lower rear elbow nut and the black canister that hangs from it.

 

Here's my method for setting the idle on a car that's had the vertical "Throttle stop" screw....well, screwed with. I don't know if it's right or wrong and frankly I don't care, because it's worked fine for me. I've looked and never found a documented method for adjusting the throttle stop screw back to spec.

First, back it off until it no longer makes contact with the throttle linkage. Now, re-tighten until the butterfly valve inside just breaks contact with the housing of the throttle body. It's been awhile, but a half turn should be more than adequate. You'll probably want to remove the elbow so you can see if the valve is still making contact. My reasoning for this is that by separating them, you are removing any wear that is going to happen between the two contacting surfaces, hopefully giving a more consistent idle over the long term, yet try to keep the gap small so you can use the bleed screw to actually adjust your idle.

Next adjust the air bleed screw to give your proper idle numbers, which should be 850 rpm, IIRC :scratch", with the "TEN" connector in the diagnostics port grounded.

Then adjust your TPS using the methods on the forum. If your idle isn't quite right after adjusting your TPS, you might have to tweak the air bleed screw again.

My two cents anyhow....

 

ok thx, i just didnt know if i should use the air bleed or the vertical one. You have to remove the cornner elbow going into the TB to adjust the air bleed right? thx for the help.

 

That's exactly right. But I will add the car must be fully warmed up and there should be no electrical loads on. Also I'd set the stop screw, then the TPS and then the air bleed. And no you don't need to remove the elbow to get to the bleed screw.

Paul

 

If you're having a really hard time setting the idle, you may want to check vacuum and compression to make sure you're engine is healthy.

With the right screwdriver, you shouldn't have to remove anything. I use the double sided insert from a harbor freight screwdriver without the handle. You could probably cut down a spare screwdriver's handle to fit.

 

i had the idle problem on my 7 too, ppl said it's the spring in the clutch switch thats failed ( above the clutch paddle) , it's a cheap fix, you can simply replace it with a spring from a pen. i fixed mine and my idle problem is gone. Here's the link.. hope this is useful.
https://www.rx7club.com/showthread.php?t=423749

 

https://www.rx7club.com/3rd-gen-archives-73/cheap-bastard-fix-clutch-switch-495391/

 

ahh ty for all the help, this has bin scaring me for the last few days. Set my TPS and the idle air bleed screw. put the set screw for the throttle valve back to its setting and it idles like new. no hunting or anything like that just idles nice at 900RPM. that wasnt so hard!