electrical problem, car won't start

[firstsupra]

I have two problems that may be related. First, something was running the battery down while the car was sitting. The battery would be stone-dead
within three days. While working on this problem the car decided it would not start. Would turn over fine, but I put the spark tester showed no spark.
I have 12 volts at the coil primary and 12 volts going to the igniter. I tried a spare igniter, but that didn't help. Last year I replaced the four pin connector
going to the cam position sensor when I had this same problem. Any ideas?
I recently put the original radio/cassett player back in the car. Do these have a memory that uses a lot of battery? Run the battery down?
The car is a 1987 7M-GTE with 115k miles.
Thanks much for any help!

 

[Nick M]

After you recharge your battery on a low amp setting, pull codes and look for 12. With everything off, put a 12 volt test light between the ground cable and negative terminal of the battery.

 

[firstsupra]

The 12 code did come up, but no others. The test did show 12 volts of current draw. I tried to get an amperage reading, but my
meter only goes to 500ma. It pegged the meter instantly at this setting.

 

[Nick M]

Fix the 12. It will not start. Without that pickup signal there is no injection. With a 12v test light, you will pull fuses one at a time to see when the light goes out. Unless you look for what is staying on. Like a vanity mirror light.

 

[jetjock]

Yeah, something isn't right. 500 mills alone is way too much parasitic.

 

[firstsupra]

Just back to basics on pulling the fuses one at a time. I thought maybe there was a connection to the starting problem or the stereo - one of
those Supra quirks. The description of code 12 was rather vague in the book I have. Does it mean crank position sensor? If so, were is it
located? I couldn't find any reference to it or any parts available. Does it mean something else? I'm still learning my way around this car!

thanks

 

[Nick M]

Well, the Supra doesn't have a stereo or starting problem quirk, so I can't say much about what is or isn't wrong. You have the car, we don't. 12 means the computer is not getting the pickup signal generated by the CPS/distributor. You don't have a distributor but a coil pack but I think you know that. Or maybe not. The cam position sensor is on the passenger side at the front. The wiring in your car is old and has been heated and cooled many times and it gets brittle over time. That is something you can look for.

If you can't get it fixed drive 22 miles to this guy's garage.

[video=youtube;TgvyparsP0c]https://www.youtube.com/watch?v=TgvyparsP0c[/video]

 

[firstsupra]

I was afraid of that... As I stated in my original question, I replaced the 4-pin connector to CPS two years ago for the same problem. I guess I will have to look at that area again. As you said, the wires are pretty well 'baked' in that area.
The video is a hoot! I live just outside of Davenport Iowa, but not 22 miles. Unfortunately most the Japanese car and "foreign" shops in this area decline to work on a Supra. The local dealer has been very helpful, but will only work on them for time and material - no firm quotes.
Thanks for your help!!!

 

[firstsupra]

Did some checking on the CPS wiring. The wiring seems to be intact and my newer 4-pin connector is good. I did the test for resistance on the three
pick-ups in the CPS. One had 160 ohms (in spec), the other two had 0 ohms. That has got to be the problem. Question, what are the best sources for
new ones, used ones, or are there rebuilds out there?
Thanks.

 

[Nick M]

Are you sure the leads were not touching? Did the display say 0.0000 or did it say OL?

 

[firstsupra]

I was careful not to touch the wrong leads together. I used short lengths of steel wire that fit well into the female connector.
I have an analog meter (Radio Shack antique). The needle did not move on two of the contacts. The third went to 160 ohms,
G2 if I remember correctly. I could check the two with a continuity tester to see if there is a direct short.
???

 

[firstsupra]

I used short pieces of steel wire inserted into the female contacts, so I was pretty sure that the leads didn't touch.
I used an analogue meter (Radio Shack antique) and the dial didn't move on two of the leads. The other went
to 160 ohms.
???

 

[Nick M]

Wiggle the wires a bit and see if it starts.

 

[firstsupra]

Wiggled the wires and nothing happened... Doesn't even try to start.

 

[Dave46]

Have you tried checking all of your grounds?
I had a no start issue that boggled my mind because all of my timing was set correctly and I had spark.. but I had a couple of loose and bad grounds.

 

[nhum]

I had similar problem with battery draining last year. Then it would not start. After reading a couple of threads, I disconnected the factory alarm and grounded the one wire from alarm harness. Car start fine now and I parked the car for 5 weeks and it still start.

 

[firstsupra]

Thanks for the tip on the factory alarm. Pulling the fuses one at a time didn't stop the current draw at the battery neg. The dash alarm light came on
while fooling with the car today. Never seen it before. Sign of something "funny" going on? Dumb question, where is the alarm located?

My number one problem - car won't start, has NO spark with good battery. A resistance check on the cam pos. sensor shows that it is bad.
Where is the best place to buy a new one? Are rebuilds available? What are good sources for used ones other than Ebay?