 Tracking down a miss |
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| jmargush |
 Sep 21 2014, 11:35 AM
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#1
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Member  Group: Members Posts: 465 Joined: 8-June 04 From: Goshen, IN Member No.: 2,176  |
2056 running L-jet
Car starts and has a noticeable miss when cold, popping while holding throttle at 2k. Once warmed up it seems to flatten out and run a bit smother. However under acceleration it just doesn't feel like it has much power and it feels like it could be running on 3 cylinders. Spark on all cylinders All 4 Injectors are spraying with good patterns Fuel filter was changed at the beginning of the summer Fuel pressure was 33 @ idle and 35 under acceleration and 39 under hard acceleration when checked the other month. I put in a new fuel pump relay due tot he old one giving me issues. The only thing left that I can think of is does the wiring harness have a broken wire in it that makes partial contact at times, but don't know if that would even create symptoms like this. Any ideas of where or what else to look for? |
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| Dave_Darling |
Sep 21 2014, 12:07 PM
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#2
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914 Idiot Group: Members Posts: 15,063 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California 
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Vacuum leaks. Points (if any). Timing advance/retard sticking. Points signal to FI has poor connection. And more...
--DD |
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| aircooledtechguy |
Sep 21 2014, 03:38 PM
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#3
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The Aircooledtech Guy Group: Members Posts: 1,966 Joined: 8-November 08 From: Anacortes, WA Member No.: 9,730 Region Association: Pacific Northwest |
You can narrow your search for the problem cylinder by first pulling loose all the plug wires off the distributor cap and lay them loosely in place. Then start the motor and one by one, pull each plug wire off with a pair of insulated pliers. When you pull the plug wire which does not effect the speed of the motor, you have found the cylinder with the issues.
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| Bob L. |
Sep 21 2014, 04:23 PM
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#4
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Senior Member Group: Members Posts: 848 Joined: 7-August 11 From: Austin TX Member No.: 13,411 Region Association: Southwest Region |
Where is the popping coming from? Intake or exhaust?
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| jmargush |
Sep 21 2014, 06:37 PM
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#5
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Member Group: Members Posts: 465 Joined: 8-June 04 From: Goshen, IN Member No.: 2,176 |
No vacuum leaks
Distributor has pertronix and was just dismantled and cleaned and relubed Popping referring to it missing while cold not a and back fire or raw gas igniting |
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