CaptainKRM

iTrader: (3)

Alright, got my FC running after it had sat for a year or so. Did the throttle body modification as well as the complete block off plate set from mazdatrix. The car is a 10AE, so S4 turbo II, running the stock top mount, stock clutch fan as well as a racing beat turbo back and rtek ecu. The car has run good so far and pulls very strong. At least until today that is.

I had driven the car up to operating temp and put about forty five minutes of drive time on the vehicle before parking for about an hour and a half. Come outside, fires right up (always a great feeling), and away we go. After about five minutes of driving, I notice that I can let my foot off the gas and the rpms stay exactly where they had been with my foot off the throttle. Depress the clutch pedal, and surprised to find the RPMs start to climb. With the car in neutral I blip the throttle and it starts to slowly idle down. On my way home, the situation progressively worsens. The only way to keep the RPM down is to have load on the engine (ie - in gear and moving). In neutral the RPMS are as high as 5,000 rpm and blipping the pedal no longer seems to release the throttle. I can cruise down the road in gear and not even use the accelerator, it acts as though cruise control is engaged. About a mile from my house the car will not idle in neutral lower than 4 or 5,000 rpms, which makes for entertaining and bemused glimpses from the motorists around you at traffic stops. When I put the car into gear and release the clutch, the RPMs drop as if they are forced to do so, but I am using the brake pedal now to hold the car back as it pulls itself away from a stop. Because racecar.

In my garage, I pull off the top mount and the throttle cable appears unencumbered and not broken. I can freely actuate the linkage on the throttle/cruise side, but on the OMP side it seems to hang up or stick to the point where I have to gently push it back closed. My question is, is there something that could be gummed up or bound up or needing adjustment to bring idle quality back down? Is there something which could have been messed up while modifying the throttle body? I was able to drive the car around on brief trips to no ill effect after doing the work/modifications. It was only after I put about an hour of drive time on it that this started to happen.

satch

iTrader: (1)

Temporarily remove the OMP rod and see if there is an improvement or not.

DC5Daniel

iTrader: (10)

I've had this same issue, the linkage connection at the actual OMP arm gets gummed up with dirt/grime. Clean it up and you should be good to go.

CaptainKRM

iTrader: (3)

No improvement

CaptainKRM

iTrader: (3)

What did you use to clean it? Pb blaster? Carb cleaner?

DC5Daniel

iTrader: (10)

Anything will work, even a little scrub with a firm bristle brush and you should be in good shape. However, if you disconnected the OMP rod and didn't see a difference I'm not sure it will do you any good. Maybe the inside of the throttle body is sticking?

CaptainKRM

iTrader: (3)

i had the throttle body off when doing 'the mod' and it was pretty clean inside. i doused both sides in PB and carb cleaner. after working the linkage by hand it seems to have freed up and snaps back better than it was. i am going to let it work in overnight, spray it down again tomorrow and take it for a drive. hopefully that is all it was.

ruddyrid

iTrader: (8)

Graphite lubricant, goes on dry so the dirt don't stick

CaptainKRM

iTrader: (3)

I probably have some of this lying around somewhere I'll look for it tomorrow evening when I get home from work

eage8

iTrader: (9)

something similar happened to me and it was the screws backing out on my TB plates causing the plates to jam. Definitely check this:

satch

iTrader: (1)

And make sure the AFM flapper door is not sticking either. Also, with the car running at the high idle you could press downwards on the rear throttle linkage and see if it has any affect on the situation.

jjwalker

This plus eleventy. Spray the linkages and springs down to clean them off, I use electrical contact cleaner.

Any hardware store will have aerosol spray graphite lube. Spray the linkages with that. Since it isn't oil based, it wont collect dirt. While your at it, go ahead and shoot some in your door lock and trunk/hatch cylinder because they probably need it.

The graphite stuff you are looking for is "Lock Lubricant". I use the brand "Lock Ease".

(BTW, just to note, never ever ever lubricate locks or throttle linkage with oil based lubricant as you will hate yourself down the road)

CaptainKRM

iTrader: (3)

So I cleaned the linkage up with carb cleaner and soaked all of it with pb blaster. Seemed to actuate freely. Had my daughter sit there and stab the throttle a bunch with the car off and it released every time. Put some wd40 on the linkage for good measure, let the car sit overnight and drove it to work. On the way there, it started sticking again. I was able to release it by stabbing the accelerator pedal, but obviously kept sticking after I'd accelerate. I've caught up on some of the posts here, so I will try some graphite lubricant today and if that doesn't free it up, I guess the throttle body is coming off.

It never did this before the car sat and before the throttle body mod was done. I drove it for twenty miles after it was all back together and it never did it.

CaptainKRM

iTrader: (3)

Still having issues, and took the throttle body off. I took a video of what it is doing here;

https://youtu.be/BKrNi43M0HM

Before anyone asks, I completely cleaned the chamber after making this video. It's spotless. Doing this had no effect and it feels like the linkage is getting bound up on itself.

CaptainKRM

iTrader: (3)

I forgot to remove the fast idle cam as part of the emissions removal, and found it binding the linkage. Removed it and the throttle operated fine. Thanks for the input everyone.