55mm TB installed now weird idle

[BathTub]

I installed a 55mm TB on my 95 ESi today. At first it idled fine but after a short drive it started to idle at 2500-3500 for about a minute before dropping to 1000-1500.
I checked to make sure everything was plugged in properly and that it was tight against the manfiold. I had the throttle cable a little tight so I losened that and it helped a little. It is still idleing at 2500 or so for about a minute before dropping to normal 800-1000.
Anyone have any ideas? I need to drive this car to work tomorrow and would like to have it idleing properly. Thanks in advance.

 

[SoilentGreen98]

Is the intake manifold modified at all? I'm also guessing you have a cold air or short ram intake too?

 

[BathTub]

No the manifold is untouched. I have a cold air intake.

 

[Dracas]

Make sure the throttle plate is completly closed.

You could try unbolting both of the screws and let the cable go loose, then see if it idles fine, if it does, then just make sure that the plate is closed when you tighten the bolts back down.

If that doesn't work, you might want to inspect the IAC to make sure you put it in correctly.

 

[BathTub]

It came with the IAC installed. What would be the proper way to install it?

 

[Dracas]

I just meant to make sure it wasn't loose or anything. So air can't get past it. I would just try to let the cable go loose and see if it idle's right, unless you know that no air is getting past the plate when its closed.

 

[GSGoinFast]

check to make sure the gasket isnt leaking. did you use any kind of sealant?

 

[SoilentGreen98]

I didn't think of that. You using a new gasket or still the same one? That could be something too. Look for any kind of leak.

 

[bullettdsm]

You might want to pop the IAC off and clean off the plunger and chamber. It is possible something got stuck in there. But more than likely, with a change like this, check for vac leaks.
MB

 

[BathTub]

I was asking how to install an IAC. Does it matter how it goes on the plate arm thing? I used a new Felpro gasket. I dont know anything about Felpro are they any good? I am thinking about using some clear Liquid Nails to seal it any thoughts on this?
I just tried loosening the cable completely and it had no affect. I could see light through the other side of the plate if I held it at an angle but it filled it up pretty fully. I have two IAC laying around here somewhere I will try. I just need to make sure I am installing them right.
I am also getting a slight stutter I forgot to mention. It only happens when I am either in too high of a gear or if I give it very little throttle on take off.

 

[BathTub]

A little update here. After driving for an hour or so I have noticed that it doesnt always idle high. Sometimes it does and sometimes it doesnt. I tried tapping the gas and see if it would go down after that but it just went back to whatever it was idleing at.

This leads me to believe that its not an air leak. I may be wrong but I would think it would always idle high or at least have some sort of pattern.

 

[speedy13]

my jeep tb used to do the same thing,a return throttle spring might help.it worked for me but it was never perfect.

 

[esi-slowboy]

Might be as simple as reseting the ecu by unplugging neg- terminal on batt for 10-15 min
then cruise around for a while it should readjust.Just a suggestion

 

[siueclipse]

i had to modify my tps.

i installed a 60mm tb and my car was doing the same shit. it would eventually fall down to 800rpm or so, which is correct. it turns out that my tps was turned when i installed it and it kept making the ecu think the throttle was open 14% when it was completely closed. the ecu freaked out and made my revs weird. i modified the mounting holes of the tps and remounted it. the ecu then saw 4% and the car started acting like normal.

 

[GSGoinFast]

Might be as simple as reseting the ecu by unplugging neg- terminal on batt for 10-15 min
then cruise around for a while it should readjust.Just a suggestion

actually you only need to un plug it for like a minute or so. you could try this

 

[BathTub]

I had the battery off when I installed it and a for a few minutes while I was trying to figure out what was wrong. I will try it again this evening. I am not getting any codes. Im going to plug in and check anyway. According to my mechanic friend he has pulled codes off of DSMs with no lights on so it cant hurt.

 

[esi-slowboy]

actually you only need to un plug it for like a minute or so. you could try this

True

 

[BathTub]

I hate life.

 

[esi-slowboy]

Roll with the punches my friend Sucks some time.
Yesterday it took me a few hours to put that windo weld urethane junk in my motor mounts Shit was all over the place PITA to work with Hard as F*** to do that crap.
Sorry for that stray
Did you get it to idle?

 

[BathTub]

UPDATE: Ok I got a check engine light a couple days after posting this. I had a friend of mine pull the codes and he said it was getting two TPS codes. I replaced the TPS and one went away.

Any thoughts on what could be causing this second code? I dont remember the actual code but my friend did say it was two TPS codes.

 

[BathTub]

Ok I just got off of the phone with my friend. According to him the code is po123a. I know that TPS high input or something like that but what would cause this? Please help!!!!

 

[XMasta19]

I had to modify my tps...it turns out that my tps was turned when i installed it and it kept making the ecu think the throttle was open 14% when it was completely closed. the ecu freaked out and made my revs weird. i modified the mounting holes of the tps and remounted it. the ecu then saw 4% and the car started acting like normal.

Well, have you checked this out yet? Sounds nice a nice place to start since you're having the same problem he was, and you're throwing tps codes as well.

 

[bullettdsm]

I could see light through the other side of the plate if I held it at an angle but it filled it up pretty fully.

I pm'ed you on this.
MB

 

[phill]

I'm gonna go ahead and assume that this has been fixed, but if not, this is what worked for me.

I put a 55mm TB on my car and had the crazy idle as well. As siueclipse said, changing the way it's mounted helped with mine but didn't completely fix the idle. So what I did was installed the sensor back in place while the neg. cable was disconnected from the battery. I then plugged the sensor back in and started the car, it idled at about 2000 RPMS and then i disconnected the plug, waited a few seconds because the RPM's were dropping and then plugged it back in.


I had been searching for awhile on how to fix this so I bet somebody else out there is doing the same thing and hopefully this helps.