This is from another sub forum here. It started with a guy trying to mate a trans
to and engine . well 100 plus post into it it turns out the first suggestion or second post was the fix!
We decided it would be fun to post our best stories about head banging obvious fixes that came about after hours days or weeks of trying to fix a car.
I'll start to get us going.
Let's go back to the mid 70"s I was driving a Datsun 510, a "friend" flipped my coil wires to make the car back fire when i went to start it. Well hah he fesses up and switches the wires back, the car starts but runs like crap. Well after I spend two weeks at nights after school and weekends to figure out whats wrong I give up. I mean I went whole hog plugs points rotor cap wires. timing carbs everything.
Finally I took it to the repair shop where are i worked part time. Well the owner pulled it into a bay and for three days he did everything I did on his dime. figuring I had gotten a bad part along the line.
Now the car ran well enough to get me to school and back about 24 mile round trip but it wouldn't get over 50 and the gas mileage was like 10-12 out of a 1400 cc motor!
Well after the boss gives up, his ace mechanic says let me take a crack at this after work. well 4 days later and a visit by a factory trained mechanic from a dealership in the next town everything is still the same, the car runs just not well.
So a month in and 3 rounds of all new parts and scope time and everything else, it still not running correctly. One last try, we put the remote starter on it and are looking at the engine and start the car shut it off and start again. nothing. We pull the coil wire and run a compression check, figuring maybe the cam had walked something the first cylinder we try, as we crank the motor the other mechanic says what's that. we see a little puff of dust come from the battery cable!!
no connection anywhere near it, just this puff of dust every time we crank it up. we pulled the positive cable of the battery and out of the first strap, there it is the way the positive cable was routed it had rubbed through the insulation and was grounding out when the engine moved, but there was enough paint and corrosion that there was only a small bit of contact. 4 inches of electrical tape around the split put it back together and the car ran fine.
over two months 4 mechanics 4 total tuneups and it took about 5 cents worth of electrical tape to fix the problem!!!