ARGH!!! More split BLM stuff [large pics]
Thread Starter
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
ARGH!!! More split BLM stuff [large pics]
Ok, so I look at all the sites saying that the throttle body could be to blame. Many aftermarket throttle bodies simply short circuit the IAC path and dump that air directly into the plenum. The symptoms are exactly what I am experiencing so I thought it might just be the problem.
I pulled the Holley TB off this morning and look what I found! Holley actually doesn't short circuit this path, it works the way it should.
I did noticed a few things though that could still cause trouble. First I see oil dripping on the front of my intake, almost looks like it had to come from behind that gasket, and two the throttle blades can use a little adjustment because I can see light around them. I'll do some tinkering and report back, but so much for the sure fire fix.
Notice the oil running down the intake? It's not coming from anywhere on the side so it almost has to be from behind the gasket. If it allows oil out it allows air in.
Another shot of the same thing
Here's the pic of the TB. You can't see the light around the blades but you can see that it has a proper IAC routing.
I pulled the Holley TB off this morning and look what I found! Holley actually doesn't short circuit this path, it works the way it should.
I did noticed a few things though that could still cause trouble. First I see oil dripping on the front of my intake, almost looks like it had to come from behind that gasket, and two the throttle blades can use a little adjustment because I can see light around them. I'll do some tinkering and report back, but so much for the sure fire fix.
Notice the oil running down the intake? It's not coming from anywhere on the side so it almost has to be from behind the gasket. If it allows oil out it allows air in.
Another shot of the same thing
Here's the pic of the TB. You can't see the light around the blades but you can see that it has a proper IAC routing.
Burning Brakes
Joined: Oct 2002
Posts: 1,152
Likes: 1
From: Wichita KS
Re: ARGH!!! More split BLM stuff [large pics] (Nathan Plemons)
I've ran into the same thing & IMHO the throttle blades don't fit correctly in the Holley T-body. Too much gap, which allows the air to bypass the IAC and dump directly into the intake. If you look at the actual T-blades in a GM/Rochester T-body the blades have an elliptical shape, which they must have as they (the blades) contact a true diameter at an angle.
I looked at my Holley & the blades are just a true diameter, which allows a large gap where they meet the T-body bore...they need to be elliptical just like the GM T-body.
I looked at my Holley & the blades are just a true diameter, which allows a large gap where they meet the T-body bore...they need to be elliptical just like the GM T-body.
Le Mans Master
Joined: Feb 1999
Posts: 9,922
Likes: 38
From: South Carolina
St. Jude Donor '03 & '05
Re: ARGH!!! More split BLM stuff [large pics] (Nathan Plemons)
Hey Nathan, I looked at some old files from when my 93 LT-1 was stock, it had split BLMS then, and every mod from rockers, to different throttle bodies, to different exhausts, cams engines etc. I have modified 3 different throttle bodies, BBK, Factory, and AS&M. No difference. I even has different manifolds. EGR off, Air off, the list goes on. I think it is a GM flaw. The only thing I havent changed is fuel rails, to the newer 94-96 as I believe they have a front crossover, which may help in fuel distribution. Also, I think our years need some "learn" time after you change something, at least Jim Formato told me that.
Race Director
Joined: Sep 2001
Posts: 14,668
Likes: 749
From: NEwhere Ohio
Re: ARGH!!! More split BLM stuff [large pics] (Nathan Plemons)
Id almost be safe to say dont worry about it.
My car always reads about 104-110 left block learn and 128 right.
I never scanned the car when stock, only after my hotcam install.
I am running a stock TB by the way. I have Ed Wright hotcam programmed custom chip as well/ 160 t-stat.
Dave
My car always reads about 104-110 left block learn and 128 right.
I never scanned the car when stock, only after my hotcam install.
I am running a stock TB by the way. I have Ed Wright hotcam programmed custom chip as well/ 160 t-stat.
Dave
