Car will not shut off...HELP!!!

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SmilingVoyeur
Newbie
Posts: 19
Joined: Sun Jan 07, 2018 3:36 pm
My tercel:: 1983 4WD Tercel Delux Wagon

Re: Car will not shut off...HELP!!!

Post by SmilingVoyeur »

I'm in Santa Fe, NM.
BTW, my mechanic has not gotten back to me about the re-wiring of the fan yet which I outlined 6 messages ago. It may seem obtuse but I think it may be the answer for my odd woes. Do you think my analysis is a worthy one?
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Petros
Highest Ranking Member
Posts: 11930
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Car will not shut off...HELP!!!

Post by Petros »

sounds good to me. without looking at the behavior, there are a number of things that can cause it. a fan by itself will not usually result in an overheat or run hot condition, unless you spend a lot of time in heavy traffic. It only comes on when idling with little air flow through the radiator.

Basic rule is to always go from all causes, that are simple to check/test/verify, and simple to fix, first. than move on to other possible causes. you must systematically check/verify each componet or part of the system one at a time. If you make a lot of changes without systematically checking it all out first, you waste time and may not fix it. Once you know the system, doing a proper check out rarely take more than 20 to 40 min, and could save hours of frustration.

YOU MUST always diagnose the problem BEFORE you try and fix it. Sounds obvious, even silly but everyone who works on cars has gotten caught up in that stupidity (myself included). You see a symptom you have seen before, and automatically think you know the cause, which may be valid. but it is important to verify it first. sooner or later you will do a repair without a proper diagnosis, and find out the problem or symptom is still present when you are all done "fixing" it. which means you just replaced good parts, and not the ones causing the problem.

some years ago I bought sight unseen rough but running Tercel4wd over the phone, it was cheap so I was not concerned, the seller even delivered it to my home. It had a number of major issues (mismatched front and rear differential ratios causes major damage to the diff, had to be replaced, brakes, wheel bearings, etc) and lots more I was not told about by the seller. Once I fixed it all, and able to drive it, I found the engine down on power. I did a power drop test. It is a simple test where you pull each spark plug wire one at a time on a fast idle, engine should slow down the same for each, but two adjoining cylinders #3 and 4, showed no change in speed. I figured the head gasket was bad, it is rare two side by side cycinder go bad at once except when the gasket between them is gone. I got ready to pull the head, but thought I should also go to the trouble of a compression test, just to make sure (what else could it be I thought? it would just waste time). I found all compression good, high in all four cylinders!. Now I was baffled, and very glad I did not pull the head. I could not think of what would cause that, but decided to carefully look over the manifold, head, instake system, etc to see if there was an obvious crack or other problem. By accident I noticed the big vac line that goes to the brake booster was disconnected from the brake booster, not an obvious problem and not even on the engine. It was allowing so much extra air into that side of the intake manifold (number 3 and 4 cyl.) that the mix was so lean it could not burn. Hence, no power from those two cylinders as revealed by the power drop test, yet still had good compression showing the gasket, rings, valves, pistons were all good.

I felt very stupid because I had my tools out ready to take the engine apart, and all I needed to do was reconnect the booster vacuum line. No tools required and took all of 30 seconds to correct. I am Glad I found it in time, but it does not still haunt me because I was so certain I knew the problem, which turns out was not. after that, and fixing 8 other vacuum leaks in the vac system, and a carb adjustment, it had great running engine, strong and reliable.

so do not just throw parts at a problem without first diagnosing the cause.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
SmilingVoyeur
Newbie
Posts: 19
Joined: Sun Jan 07, 2018 3:36 pm
My tercel:: 1983 4WD Tercel Delux Wagon

Re: Car will not shut off...HELP!!!

Post by SmilingVoyeur »

It worked. My car is fine now and after driving 60 miles and shutting the engine off everything shut down. So if you see my earlier post "I think I have figured it all out" you can learn how this was done.
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