Ported Throttle Body issues
Ported Throttle Body issues Car is a 2000 TA, M6.
Ok, finished porting and installing my throttle body yesterday (core was a '98/99, but I switched my 2000 throttle cam into the ported body). A couple of things I've noticed since driving it.
1. On cold starts, after the initial throttle surge, the car immediately levels off to about 500RPM, a good 200 or more lower than it used to. After about 30 seconds, it comes back up to normal levels. Any ideas what could cause this?
2. If I let the car engine brake, it slows down noticibly faster than with the stock throttle body. Maybe the throttle blade just has a faster response now?
3. The gas pedal seems to stick slightly after I take my foot off of it. Takes a bit more pressure to get it to release and start giving it gas. Doesn't stick at any other spot in the throttle range.
Particulars of the throttle body. I filled in the "gap" with JB Weld and redrilled the two holes that were supposed to be there. Removed as much material as I felt was safe (and about as much as I was told by a couple people that have done this a lot), smoothed out the taper from the lip of the TB to a little more than a 1/4" in front of the blade. Smoothed off the front of the blade and polished it. Did NOT redrill the hole in the blade. Shaved the front off the bladeholder (rod attached to the throttle cam). Only the blade and body itself are from the '98/99 core, everything else is from my stock TB (TB cam, sensors, etc).
Any ideas?
Ok, finished porting and installing my throttle body yesterday (core was a '98/99, but I switched my 2000 throttle cam into the ported body). A couple of things I've noticed since driving it.
1. On cold starts, after the initial throttle surge, the car immediately levels off to about 500RPM, a good 200 or more lower than it used to. After about 30 seconds, it comes back up to normal levels. Any ideas what could cause this?
2. If I let the car engine brake, it slows down noticibly faster than with the stock throttle body. Maybe the throttle blade just has a faster response now?
3. The gas pedal seems to stick slightly after I take my foot off of it. Takes a bit more pressure to get it to release and start giving it gas. Doesn't stick at any other spot in the throttle range.
Particulars of the throttle body. I filled in the "gap" with JB Weld and redrilled the two holes that were supposed to be there. Removed as much material as I felt was safe (and about as much as I was told by a couple people that have done this a lot), smoothed out the taper from the lip of the TB to a little more than a 1/4" in front of the blade. Smoothed off the front of the blade and polished it. Did NOT redrill the hole in the blade. Shaved the front off the bladeholder (rod attached to the throttle cam). Only the blade and body itself are from the '98/99 core, everything else is from my stock TB (TB cam, sensors, etc).
Any ideas?
I had similiar problems to what you were mentioning when I first ported my TB. I started it up twice and it idled like @$$. When I reved it, it would bog on me. When I started it the third time, it seemed perfectly fine. The only advice I can give you at this point is to just start it up a few times and try and let everything settle. If it doesn't idle properly, then just shut it off and try again.
If you ported too far then that could also be the problem. If you ported near the blade, ur gonna need a new TB.
If you ported too far then that could also be the problem. If you ported near the blade, ur gonna need a new TB.
Thanks for the quick response... Have started the car several times since installing the TB. A couple times last night, and drove to work today. It seemed to get slightly better, but it still idles low on a cold start (by cold, I mean not full operating temperature). As for porting to close to the blade, I never got closer than a quarter of an inch to the blade seat line. I'm thinking that the idea might have to do with the size of the holes I drilled for the sensors OR I might have possibly put the stock cam spring on too tight.
I also noticed that on the cam idle stop, there is a set screw. Think adjusting this would help?
I also noticed that on the cam idle stop, there is a set screw. Think adjusting this would help?
TECH Resident
Joined: Aug 2003
Posts: 960
Likes: 1
From: Central, FL
hey bro, I think that if it is getting even a little bit better than it was, the PCM is learning the new addition of airflow. I say give a couple days, it should level off enough.
on the other hand, I heard from a few peeps, that a good ported TB sometimes needs tuned. but, I think it should level off in a few days.
keep me updated via phone or N2S.
check the cam and stuff, but should be okay
on the other hand, I heard from a few peeps, that a good ported TB sometimes needs tuned. but, I think it should level off in a few days.
keep me updated via phone or N2S.
check the cam and stuff, but should be okay
