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2005 CTS-V Maggied
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Discussion Starter #1
So I'm now looking for my 3rd LS6 throttlebody.... Anybody have any ideas what could possibly be killing my throttlebodies? Stock one went at 25k miles. Second oem replacement went at 18k miles. Right now the car is basically dead until I put another TB on it so I'm looking at options.

It is currently throwing P0120, P0220, P1516, P2101. It threw these codes the last time and replacing the TB resolved it for 18,000miles up until now.

Any ideas?? Maggie related? I do "exercise" the throttle quite a bit.

Thanks.
 

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2005 CTS-V
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I used to throw one or more of those codes very intermittently. The problem has disappeared since I installed a ground strap from the grounding point underneath the hood stick to the grounding point on the back of the passenger side head, and another ground strap between the grounding point on the back passenger-side head and the grounding point on the back of the driver-side head.

See also attached.
 

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2005 CTS-V Maggied
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Discussion Starter #3
I used to throw one or more of those codes very intermittently. The problem has disappeared since I installed a ground strap from the grounding point underneath the hood stick to the grounding point on the back of the passenger side head, and another ground strap between the grounding point on the back passenger-side head and the grounding point on the back of the driver-side head.

See also attached.
Thank you sir.

It seems my TPS may be suspect. I have a new one on order to see if that will fix it. I put my old intermittent throttlebody TPS sensor in the car and it started up good then went back into limp mode like it normally did back when I had that TB in a year+ ago so that is a good indicator it might just be the TPS sensor that is going bad, not the rest of the TB.

It never hurts to have extra grounding. I'll add that to the "to-do" list.

If the TPS sensor doesn't resolve it I'm going to buy a new 90mm TB and go that route instead of buying a new LS6 TB.
 

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I had my LS6 TB go bad not too long after putting on my maggie. It was replaced and has now been working without issue for the better part of a decade.

p.s. I was going to upgrade mine to a 90mm once upon a time but never did so I have a TB, adapter harness, and the new front for the maggie laying in my garage.
 

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2005 CTS-V Maggied
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Discussion Starter #7
I had my LS6 TB go bad not too long after putting on my maggie. It was replaced and has now been working without issue for the better part of a decade.

p.s. I was going to upgrade mine to a 90mm once upon a time but never did so I have a TB, adapter harness, and the new front for the maggie laying in my garage.
Pm'd you for info on the parts.
 

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Discussion Starter #8
So I determined that the LS6 TB's were toast due to deformed springs internally, so nothing to really salvage. The 90mm are supposed to have beefier return springs so this should help with my situation.

So I got all my parts together: 90mm LS2 TB from rockauto, 90mm Maggie snout and Caspers conversion harness and 4x longer M6x45mm-1.00 pitch bolts. The 90mm snout is a bit thicker than the 78mm snout.

Thanks to Ronr for having an unused 90mm snout and harness just waiting for me to buy :)

I was able to clean up some of the maggie hose hell by getting rid of the TPS extension harness and T'ing in the passenger side PCV line to the driver side snout vac line as there is no provision on the 90mm TB for that hose. I wasn't in the mood to cut a hole in the intake at this point. I cleaned up most of the vac line routing and made sure nothing was going to be rubbing on the jack shaft with some zip ties to keep everything secure.

Another thing I did was eliminate the line that was used to the throttlebody heater on the LS6 TB. Since the 90mm TB doesn't have that (nor was I going to keep it if it did) I just plumbed from the block valley across to under the radiator cover and back to the factory T without having to modify the lines very much.

There is no gasket between the snout and the supercharger housing. Maggie suggested I use loctite 510 to form a seal between the two. That stuff is expensive but works great.

My Bypass valve was also hooked up to a small sensor looking thing on the firewall that has a wire going to the magnavolt. It also had a vac line going from the 78mm snout back to the sensor, and another vac line going to the bypass valve. My tuner and I found that whatever that thing is was actually preventing the bypass to open at idle causing the supercharger to make some excellent rock crushing noise. pushing the bypass valve manually made the noise go away. So when I started re-routing things for the 90mm conversion I eliminated that "sensor thing" and just put a direct vac line from the bypass to the snout. Idles good and sounds normal now. Since I did this though I definitely need to get it re-tuned as it surges off throttle then eventually stabilizes. minor stuff, but overall great success.

Next step is to delete the maggie fuel return loop hose and plug the stock fuel line into the opposite side of fuel manifold (needs to be drilled out) and plug other end with an oring'd fitting.

Before



Some pics of the new 90mm vs. old 78mm parts. Quite a huge difference between the two parts.



After
[/QUOTE]
 

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Looks great. Glad you were able to put the parts to use!
 

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I was ready to do this (parts were in hand), but elected to stay with the 78mm TB. Didn't want to tempt mod hell.

BUT, I'm dying to know what you dyno at with this setup. :yup:
 

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Discussion Starter #11
I was ready to do this (parts were in hand), but elected to stay with the 78mm TB. Didn't want to tempt mod hell.

BUT, I'm dying to know what you dyno at with this setup. :yup:
Tune touch up + new dyno pull are on my to do list now. Should be interesting to see what if any gains I'll get with it. I went this route so I won't hopefully have to replace another TB.
 
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