 L-jet help needed |
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| wanchaiwarrior |
 May 2 2010, 01:48 PM
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#1
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Newbie  Group: Members Posts: 21 Joined: 16-January 10 From: Los Angeles Member No.: 11,242 Region Association: Southern California  |
74 1.8L L-jet was running well before I decided to give the engine a good cleaning and replace all the old vacuum lines. Now it idles great, but as soon as I go beyond 1/10th throttle it just losses all power. At low throttle it will run all the way to 4,000+RPM. But beyond a certain throttle position, regardless of RPM, it just goes limp.
2 months ago I performed a full tune, including valve adjust, pertronix, plugs, rotor, cap. I have triple checked my vacuum hose connections and electrical connections. I even pulled the throttle body off and checked the TPS operation, which appears to be operating properly. Oddly, my throttle body only has one port that goes to the back side of the vacuum advance diaphragm leaving the port on the front of the vacuum advance open. It definitely seems to be related to throttle position. Not sure where to try next. Any suggestions would be greatly appreciated. |
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Replies
| Cap'n Krusty |
May 2 2010, 10:50 PM
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#2
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Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
QUOTE(wanchaiwarrior @ May 2 2010, 12:48 PM)  74 1.8L L-jet was running well before I decided to give the engine a good cleaning and replace all the old vacuum lines. Now it idles great, but as soon as I go beyond 1/10th throttle it just losses all power. At low throttle it will run all the way to 4,000+RPM. But beyond a certain throttle position, regardless of RPM, it just goes limp. 2 months ago I performed a full tune, including valve adjust, pertronix, plugs, rotor, cap. I have triple checked my vacuum hose connections and electrical connections. I even pulled the throttle body off and checked the TPS operation, which appears to be operating properly. Oddly, my throttle body only has one port that goes to the back side of the vacuum advance diaphragm leaving the port on the front of the vacuum advance open. It definitely seems to be related to throttle position. Not sure where to try next. Any suggestions would be greatly appreciated. '74s have both an advance port and a retard port on the TB. Actually, '75s do, too. This is NOT debatable. Go look for them. The Cap'n |
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| zonedoubt |
May 5 2010, 02:35 PM
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#3
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Canadian Member Group: Members Posts: 668 Joined: 14-May 03 From: Vancouver, BC Member No.: 696 Region Association: Canada |
QUOTE(Cap'n Krusty @ May 2 2010, 08:50 PM) '74s have both an advance port and a retard port on the TB. Actually, '75s do, too. This is NOT debatable. Go look for them. I have a '75 with only one port on the throttle body. (IMG:style_emoticons/default/confused24.gif) |
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| Drums66 |
May 5 2010, 03:54 PM
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#4
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914 Rudiments Group: Members Posts: 5,321 Joined: 15-January 03 From: Coronado,Cali Member No.: 151 Region Association: Southwest Region |
QUOTE(zonedoubt @ May 5 2010, 01:35 PM) QUOTE(Cap'n Krusty @ May 2 2010, 08:50 PM) '74s have both an advance port and a retard port on the TB. Actually, '75s do, too. This is NOT debatable. Go look for them. I have a '75 with only one port on the throttle body. (IMG:style_emoticons/default/confused24.gif) Mine as well? (IMG:style_emoticons/default/stirthepot.gif) (IMG:style_emoticons/default/popcorn[1].gif)(one port 75') |
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Posts in this topic
wanchaiwarrior L-jet help needed May 2 2010, 01:48 PM
jsayre914 the port should not be open to air.
check for a n... May 2 2010, 02:08 PM
wanchaiwarrior I prepared a detailed diagram before I started dis... May 2 2010, 02:24 PM messix
I prepared a detailed diagram before I started di... May 2 2010, 03:09 PM wanchaiwarrior I actually removed the air box before cleaning, so... May 2 2010, 03:53 PM MrKona
74 1.8L L-jet was running well before I decided t... May 2 2010, 03:51 PM wanchaiwarrior Are you referring to this port?
[/quote]
Yes, tha... May 2 2010, 03:57 PM computers4kids Did you remember to plug the harness back into the... May 2 2010, 04:30 PM wanchaiwarrior
Did you remember to plug the harness back into th... May 2 2010, 04:33 PM computers4kids
Did you remember to plug the harness back into t... May 2 2010, 10:00 PM wanchaiwarrior I opened up my air flow sensor and discovered the ... May 2 2010, 06:31 PM Brando To address this issue later on in Motronic cars, B... May 3 2010, 12:26 AM zonedoubt
More info on AFM rebuilding & diagnostics [ur... May 5 2010, 02:34 PM messix thats were i thought you might have had the proble... May 2 2010, 09:32 PM wanchaiwarrior '74s have both an advance port and a retard po... May 3 2010, 09:51 AM charliew Nice engineering change to know about. At first to... May 3 2010, 08:34 AM ClayPerrine I normally agree with Cap'n Crusty, but on thi... May 3 2010, 01:07 PM Drums66 I'm surprised no 1 told you not to go inside t... May 5 2010, 01:37 PM wanchaiwarrior
I'm surprised no 1 told you not to go inside ... May 5 2010, 02:16 PM |
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