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clapeza |
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#1
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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 ![]() ![]() |
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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Spoke |
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#2
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Jerry ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 7,158 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None ![]() ![]() |
When you started your car, did the starter strain to start the car or did it turn over nicely?
If it turned over nicely, likely your transmission ground strap is ok. If the spring heats up while running, then your alternator is grounding through the spring. Did you have the engine out and do some painting on the fan shroud? If you add a ground strap to the alternator, attach the other end to the engine case, not the fan shroud. The alternator already is grounded to the fan shroud. BTW, for a transmission ground strap, I picked up a standard starter cable like this one at my FLAPS. I think the one I picked up was either 2ga or 4ga 12 inches long. It was longer than the original so I looped it once. Starter Cable Attached image(s) ![]() |
clapeza |
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#3
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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 ![]() ![]() |
When you started your car, did the starter strain to start the car or did it turn over nicely? If it turned over nicely, likely your transmission ground strap is ok. If the spring heats up while running, then your alternator is grounding through the spring. Did you have the engine out and do some painting on the fan shroud? If you add a ground strap to the alternator, attach the other end to the engine case, not the fan shroud. The alternator already is grounded to the fan shroud. BTW, for a transmission ground strap, I picked up a standard starter cable like this one at my FLAPS. I think the one I picked up was either 2ga or 4ga 12 inches long. It was longer than the original so I looped it once. Starter Cable The starter has always sounded and run strong. That's kinda why all the discussion around the transmission ground strap always seems to come back to talk about how well the starter pulls - this puzzled me. Mine seems fine. That's what led to the idea of the extra ground for the engine and not straight to the transmission. I have not had the engine out of the car. The new ground cable I bought looks exactly like the one you pictured. It's the one from the rearmost case bolt in the engine compartment going straight to the battery's ground post. I'll look at the transmission ground and also look into a supplemental ground for the alternator. I finally got her off the jack stands. I guess she missed them!! Thanks, Spoke! |
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