1973 1.7L bucking skipping backfiring thru engine, 1973 1.7L bucking skipping backfiring thru engine |
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1973 1.7L bucking skipping backfiring thru engine, 1973 1.7L bucking skipping backfiring thru engine |
johnoscar |
Jul 9 2022, 10:09 AM
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#21
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Newbie Group: Members Posts: 11 Joined: 23-May 22 From: Westfield, Massachusetts Member No.: 26,569 Region Association: North East States |
My guess is the condenser. If I read the thread right, the replacement had a wire that was too short. So you didn’t replace it.(?) Extend the wire and try it. you are correct. the condenser wire from bosch was too short. called george at aa. the posts about the condenser wire are about 2 years oid and he didn't know anything about it. he had to ask someone in his repair garage, but did confirm, since, i have replaced the distributor with 123ignition, without any change. |
johnoscar |
Jul 9 2022, 10:14 AM
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#22
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Newbie Group: Members Posts: 11 Joined: 23-May 22 From: Westfield, Massachusetts Member No.: 26,569 Region Association: North East States |
It could be a vacuum leak. You say you have had issues finding shops to look at it. Maybe snap some pics of the engine and let us take a look. (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) There is a guy in the Springfield area - close to you called Hurst Injectors (https://hurstinjectorservice.com/) - GREAT GUY - GREAT WORK, knows Bosch like the back of his hand - the injectors might need a refresh - short money........ If the car sat for a while prior to this FUN - I would STRONGLY suggest starting with the vacuum circuit. Everything connected to the Plenum (box under the Throttle Body - where the throttle cable goes) must be air-tight. The Plenum itself will rust and leak........ I chased the same thing for months and finally checked the vacuum, if there are leaks the car will lose it's mind...... Oh, I am in Arlington - trailer it here and I will troubleshoot for you......N/C ty. didn't know that. i'll follow up on what he does. your offer is more than kind and appreciated very much. i may be in contact with you....too good to pass up. |
emerygt350 |
Jul 9 2022, 03:16 PM
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#23
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Advanced Member Group: Members Posts: 2,403 Joined: 20-July 21 From: Upstate, NY Member No.: 25,740 Region Association: North East States |
Wouldn't there be no spark if it were the condenser?
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ChrisFoley |
Jul 10 2022, 08:57 AM
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#24
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I am Tangerine Racing Group: Members Posts: 7,958 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None |
ctc911ctc has a 2L engine. The 1.7L plenum is different, and not prone to cracking as the 2L unit is.
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johnoscar |
Jul 10 2022, 02:42 PM
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#25
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Newbie Group: Members Posts: 11 Joined: 23-May 22 From: Westfield, Massachusetts Member No.: 26,569 Region Association: North East States |
i don't want to say this ........but burnt valve? or an exhaust valve that never sealed properly and its gotten worse and worse. symptoms fit. EDIT well done for being the one and only owner. stick with it. (IMG:style_emoticons/default/beerchug.gif) That, sadly, was my next question as well. Have you done a compression test? cyl1=158 cyl2=155 cyl3=165 cyl4=154 all psi (all cold) |
emerygt350 |
Jul 10 2022, 05:40 PM
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#26
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Advanced Member Group: Members Posts: 2,403 Joined: 20-July 21 From: Upstate, NY Member No.: 25,740 Region Association: North East States |
Those numbers are great. That really only leaves peripherals. Get on the vacuum lines. Get us pictures.
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ctc911ctc |
Jul 11 2022, 07:28 AM
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#27
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Senior Member Group: Members Posts: 915 Joined: 9-June 18 From: boston Member No.: 22,206 Region Association: North East States |
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Highland |
Jul 11 2022, 01:52 PM
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#28
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Senior Member Group: Members Posts: 526 Joined: 8-August 11 From: San Diego, CA Member No.: 13,418 Region Association: Southern California |
Chris, Good to see your post - hope all is well - it has been a long time since I owned a 1.7, I was not aware that the plenum was different, Thank you, ctc911ctc has a 2L engine. The 1.7L plenum is different, and not prone to cracking as the 2L unit is. Is the type 4 2L bus’ plenum similar in shape to the 1.7L plenum? If so, why did they elect to use a different 2L plenum design on the 914? |
wonkipop |
Jul 11 2022, 04:24 PM
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#29
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Advanced Member Group: Members Posts: 4,623 Joined: 6-May 20 From: north antarctica Member No.: 24,231 Region Association: NineFourteenerVille |
Chris, Good to see your post - hope all is well - it has been a long time since I owned a 1.7, I was not aware that the plenum was different, Thank you, ctc911ctc has a 2L engine. The 1.7L plenum is different, and not prone to cracking as the 2L unit is. Is the type 4 2L bus’ plenum similar in shape to the 1.7L plenum? If so, why did they elect to use a different 2L plenum design on the 914? i could be wrong about this - but the bus 2.0 L was either twin carb (in most of the world except the USA) or if EFI it ran L jetronic. the VW version for the bus came a few years after the 2.0 developed by porsche for the 914 which is D jetronic. porsche designed a fairly unique intake plenum and throttle body for the 914 2.0 the one that is on the VW 2.0 is more like the intake plenum and throttle body on the 1.8 L jets or the 2.0 912E. |
johnoscar |
Jul 11 2022, 05:20 PM
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#30
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Newbie Group: Members Posts: 11 Joined: 23-May 22 From: Westfield, Massachusetts Member No.: 26,569 Region Association: North East States |
Check all the grounds on the engine. TY for the reply. That has been done. What has not been done is following ECU to all connective points. Super important. You need to test the FI harness for continuity. All it takes is a DVM (Digital Volt Meter). Jeff....does your site have a diagram of what wires at the ECU go to which wires at the other end?? |
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