 Grounding through throttle cable, Return spring burned the crap outta me! - SOLVED |
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| clapeza |
 Aug 8 2017, 07:14 PM
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Member  Group: Members Posts: 229 Joined: 7-February 11 From: South GA Member No.: 12,677 Region Association: South East States 
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Got the FI back in my car (1970 1.7L) and working recently. The PO had cut the throttle cable for the carb conversion, so I installed a new TerryCable.
I noticed that the throttle cable got hot. I figured that the ground strap was corroded or broken (I can see it, but can't get to it now.) I installed a new ground from the rearmost engine case bolt to the battery ground stud on the passenger side of the engine compartment. I used a generic 4 ga battery ground cable from my FLAPS. One end is on top of the battery ground cable. The other is on the bolt that holds the oil bath air cleaner "shelf". This end of the cable is sandwiched between 2 washers on top of the shelf arm that the bolt goes through, with the nut holding it all down tight. I cranked the car and it ran easily, and the throttle cable was no longer hot, or even warm. Success? Not so fast... I then replaced the bushings in the accelerator pedal bracket, so it's nice and smooth now. Didn't get a chance to crank it because I ran out of time that day. I cranked it today, and blipped the throttle by hand on the throttle body. I thought I saw a tiny spark at the throttle return spring where it attaches to the rear wall. I touched the spring lightly with my finger and burned the crap out of it! The engine had been running only about 10 seconds at this point. What gives? Theory: The new accelerator pedal bushings improved the electrical connection to the body. The new grounding cable isn't making good enough contact to the engine case, so the engine is still preferring to ground through the throttle cable. Assumption: A 4ga cable connected from the engine case straight to the body where the battery connects is an equal (if not superior) ground compared to the transmission ground strap. I still plan on inspecting and possibly replacing the transmission ground strap, but I'm curious as to why I burned my finger... Ideas? Advice? |
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Aug 13 2017, 07:24 PM
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Repeat Offender & Resident Subaru Antagonist Group: Members Posts: 13,700 Joined: 23-January 09 From: Temecula, CA Member No.: 9,964 Region Association: Southern California
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Have you tried pulling one fuse at a time until the voltage drops to 0?
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Posts in this topic
clapeza Grounding through throttle cable Aug 8 2017, 07:14 PM
Racer Chris The problem is where you have your ground attached... Aug 8 2017, 07:21 PM GeorgeRud I wonder if running the ground strap from a starte... Aug 8 2017, 08:20 PM The Cabinetmaker Electricity follows the path of least resistance. Aug 8 2017, 08:28 PM Spoke
I cranked it today, and blipped the throttle by h... Aug 9 2017, 05:09 AM
clapeza
I cranked it today, and blipped the throttle by ... Aug 9 2017, 06:26 AM cali914 Yeah I heard if you don't have a transmission ... Aug 9 2017, 09:29 AM clapeza
Yeah I heard if you don't have a transmission... Aug 9 2017, 09:56 AM Mikey914
Yeah I heard if you don't have a transmission... Aug 9 2017, 10:04 AM Eric_Shea The factory has a solution. It should really only... Aug 9 2017, 10:03 AM clapeza
The factory has a solution. It should really onl... Aug 9 2017, 12:10 PM Spoke When you started your car, did the starter strain ... Aug 9 2017, 12:55 PM clapeza
When you started your car, did the starter strain... Aug 9 2017, 01:13 PM Spoke
It's the one from the rearmost case bolt in t... Aug 9 2017, 03:18 PM clapeza
It's the one from the rearmost case bolt in ... Aug 9 2017, 06:48 PM Spoke Here's a pic of the ground strap I'm using... Aug 9 2017, 01:05 PM Tom_T Clean the connections/studes & cable/strap, ... Aug 9 2017, 04:18 PM N_Jay You grounded the engine, good for stating, but lef... Aug 9 2017, 04:27 PM Larmo63 This isn't rocket science.......
Aug 9 2017, 04:32 PM clapeza I replaced the transmission ground strap with a ne... Aug 12 2017, 08:14 PM Perry Kiehl Was the transmission or engine case painted? Just... Aug 13 2017, 01:09 PM Spoke That's really funky. Is the alternator chargin... Aug 13 2017, 01:16 PM clapeza I got a ground cable exactly like the one in Spoke... Aug 13 2017, 03:43 PM clapeza I did some voltage testing, all at the battery:
Ca... Aug 13 2017, 05:49 PM Spoke This is really weird. The entire engine case, FI c... Aug 13 2017, 07:04 PM Spoke
Have you tried pulling one fuse at a time until t... Aug 14 2017, 11:01 AM clapeza I did some quick testing this afternoon, and came ... Aug 16 2017, 08:08 PM Spoke It is possible that AAR wire is shorting to its ca... Aug 17 2017, 04:02 AM Racer Chris Your plenum must be insulated from the crankcase o... Aug 17 2017, 06:56 AM clapeza GOT IT!!
I disconnected the wire to the A... Aug 17 2017, 05:46 PM |
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