View Full Version : stopping boost creep
Big_P
09-22-2007, 05:49 PM
I just bought an 88 LeBaron GTS. Previous owner installed a 2.5" exhaust and promptly sold it before using it.
The boost goes up to 12, then promptly goes up to 20!! I'm surprised I don't hit cut-out. I do NOT want to blow this motor up.
How can I stop this? The motor is completely stock.
What can I doooooo?
Thanks.
turbovanmanČ
09-22-2007, 11:11 PM
What are you using for boost control?
Big_P
09-23-2007, 01:52 AM
Whatever the factory uses. The solenoid, I assume.
Right now I have it plumbed into the intake mani, I'm getting 6psi and no creep.
Slowwwww.
turbovanmanČ
09-24-2007, 07:15 AM
Check for the restrictor on the wastegate hose and make sure the vacuum lines for the solenoid are routed properly.
Big_P
09-24-2007, 08:58 PM
I installed a home-made MBC. I went to the Deep Homo, erm, home depot, and got a teensy valve and plumbed it in. Anyway...I got it tuned to about 14psi...
However, as soon as I bang 2nd gear it stays at 7psi, spikes to 10, then stays at 7 again. This is so weird. It's been a long, long time since I've had a Turbo Dodge (that ran).
Big_P
09-24-2007, 08:59 PM
BTW, it's a TII with a 555 tranny.
turbovanmanČ
09-24-2007, 09:08 PM
I installed a home-made MBC. I went to the Deep Homo, erm, home depot, and got a teensy valve and plumbed it in. Anyway...I got it tuned to about 14psi...
However, as soon as I bang 2nd gear it stays at 7psi, spikes to 10, then stays at 7 again. This is so weird. It's been a long, long time since I've had a Turbo Dodge (that ran).
If the boost was solid using just manifold vacuum then your controller isn't very good. DId you remove the restricter?
Big_P
09-24-2007, 11:49 PM
the MBC i used went straight from the brake booster to the boost controller, to the wastegate.
I don't know what restrictor you speak of.
I'm about to just throw some +20's and an A/F meter on it and let it boost to it's hearts content.
turbovanmanČ
09-25-2007, 12:28 AM
the MBC i used went straight from the brake booster to the boost controller, to the wastegate.
I don't know what restrictor you speak of.
I'm about to just throw some +20's and an A/F meter on it and let it boost to it's hearts content.
You didn't answer about the 6 psi?
The factory puts a bleed/restrictor in the wastegate line.
Big_P
09-25-2007, 02:38 PM
If the boost was solid using just manifold vacuum then your controller isn't very good. DId you remove the restricter?
Does the restrictor look like a normal vacuum line barb?
Well, if so, I did not bypass it, I just replaced the hard line with a rubber line.
would it be beneficial if I removed the restrictor?
turbovanmanČ
09-25-2007, 02:46 PM
Does the restrictor look like a normal vacuum line barb?
Well, if so, I did not bypass it, I just replaced the hard line with a rubber line.
would it be beneficial if I removed the restrictor?
Remove it when running a MBC.
Big_P
09-25-2007, 06:38 PM
K. Done. Removed.
Boost is set to 12psi. Runs good up there.
I noticed the 2.2 likes to rev a lot more than my 2.5.
I get 12psi in 1st gear, but only about 7 in the rest of them. Am I doing something wrong?
Sorry to bombard you with all these questions, Simon, but you're the only one that is willing to give me some advice. I'll stop soon, I promise.
mcsvt
09-25-2007, 07:12 PM
Possible boost leak I'd say. Or weak wastegate...
Have you tried the "disconnect WG" test? Did the boost sky rocket?
As a side node you should have bought a car that had this sorted out already :lol:
hmm, that statement leads me to believe you are part of the 99% of people here who can find turbo dodges to buy. congratulations. please send a turbo dodge to San Antonio, Texas asap.
:p
turbovanmanČ
09-25-2007, 08:52 PM
K. Done. Removed.
Boost is set to 12psi. Runs good up there.
I noticed the 2.2 likes to rev a lot more than my 2.5.
I get 12psi in 1st gear, but only about 7 in the rest of them. Am I doing something wrong?
Sorry to bombard you with all these questions, Simon, but you're the only one that is willing to give me some advice. I'll stop soon, I promise.
I'd venture to guess at a crappy MBC or it could be the wastegate is getting weak. Have you tried a vacuum pump on the wastegate to see if she'll hold?
No worries about the questions, this part I am a bit hazy on but can help I think, :confused:
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