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jrmdir |
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#1
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Member ![]() ![]() Group: Members Posts: 224 Joined: 13-May 21 From: Central Ohio Member No.: 25,544 Region Association: Upper MidWest ![]() ![]() |
After months of chasing a rich condition on my '73 1.7 I decided to once again try pressurizing the system and applying soapy water. Glad I did because I found two more leaking hoses and a leaking Cold Start Valve gasket. But the worst culprit turned out to be a leak around the throttle shaft.
There are a number of threads about options for adding bushings and or seals, but am I right in thinking this would mainly impact idle mixture? If so, I'm wondering if other system adjustments, e.g. ECU knob and/or MPS could overcome the effects of this leak - at least until I find a machine shop to fix the TB. Thanks in advance for any suggestions. Ron |
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JamesM |
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#2
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Senior Member ![]() ![]() ![]() Group: Members Posts: 1,922 Joined: 6-April 06 From: Kearns, UT Member No.: 5,834 Region Association: Intermountain Region ![]() |
Leak wont affect mixture with d-jet, just idle speed.
I think your bigger issue though is that it may wind up giving you a constantly changing idle speed in operation as the severity of the leak varies every time the throttle is closed. thankfully they made a ton of 1.7s and no one seems to want them, so you should be able to find another TB pretty easily. |
914_teener |
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#3
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 5,205 Joined: 31-August 08 From: So. Cal Member No.: 9,489 Region Association: Southern California ![]() |
Leak wont affect mixture with d-jet, just idle speed. I think your bigger issue though is that it may wind up giving you a constantly changing idle speed in operation as the severity of the leak varies every time the throttle is closed. thankfully they made a ton of 1.7s and no one seems to want them, so you should be able to find another TB pretty easily. For once I might slightly disagree with James. Part load will be affected/throttle response along with idle speed. I had this exact problem. I'd agree there are tons of 1.7 TB's and I'd find another instead of having it rebushed. It really depends where the leak is. A leak in the plenum is exposed to high manifold vacuum depending on the position of the throttle plate affecting the mixture across all driving ranges. Most driving is done under part load to idle. So driveablility will be affected the most. |
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