cps acting fishy
 

So i have been suffering massive powerloss and my 89 7mgte is kicking out a code12 meaning the cps, cps circuit, or ecu is broken or malfunctioning. SO i checked the cps and low and behold the cap was cracked. I got a newone from ebay and when i popedthe cap off i noticed there was oil inside the cps. Also the gasketlooked as if it had been melted neer where the wires enter the side of the cps. A brown wire on the right looked as if it has been burnt. So i check the cps but the gaps are still below 4mm and the resistance on the wires checkes out. SO the next step im guessing is to make sure the connection from cps to the ecu is solid but am at a loss as how to do so. I have a tsrm but all it says it "check the circuit" not how to do so =/.

Questions, comments,answeres? Anyone heard of oil gettin in the cps or think it could be related to the problem?

If there is oil inside the CPS then it can coat the parts and mask some of the signals so yes oil inside is not good. You can clean it out with contact cleaner fire it up and see if it gets any better, then you know the wires are good and you can just replace the seals from toyota.
If it still runs like crap then troubleshoot with this link,
http://www.cygnusx1.net/Supra/Librar....aspx?S=IG&P=3

or this
http://www.cygnusx1.net/Supra/Librar...aspx?S=IG&P=16

read the wires from the CPS to the ECU with this to ensure the engine harness is good.
http://www.cygnusx1.net/Supra/Librar...px?S=Main&P=40

here is an exploded view of the CPS
http://www.cygnusx1.net/Supra/Librar...aspx?S=IG&P=21
Make sure the O Ring is good. You can probably go to NAPA to get a replacement. It just prevents oil from leaking out onto the block. Since your CPS is internally leaking then the inner bushings might be shot.
Ive never taken one apart but my mercedes distributor uses the engine oil to lube the inside of the shaft and there are inner bushings and seals that go after a long life. The dealer says to replace the distributor, I had a mechanic fix the bushing. he replaced the seal with a new one and added a little piece of felt to catch any oil that got by and it would go out the weep hole and not sling all the parts inside.
I have injector triggers in the distributor which got gummed from the oil.

Don't forget to reset the ECU by pulling the EFI fuse or the code will stay stored.

kk
 

Wow, Thanks for all the help, i have today off so ima get to some of that hopefully and reply with results, thanks again.

ok so
 

so i checked the wiring (ne, g1, g-, g2) between the CPS and the ECU following the instruction in the tsrm on page fi-123. The Impedence (ohms) of the G1, G2, and ne to the g- circuit was suposed to be from 140-180 and they all check in around 175-177. So on the high side but still functionall. i am still at a loss as to why the car is kicking out a code 12.

Did you remove the EFI fuse for at least 30 seconds?
It is possible the CPS isn't picking up the signal correctly but try resetting the ECU first.

mhm
 

Well The car also has a problem with the headlights staying on so when i sit the car i remove the (-) battery cable. and in the tsrm page FI-25 it states " cancellation can also be done by removing the battery (-) terminal," So effectivly i have been reseting the codes everytime i put her away for the nite. Im debating buying a new cps and ecu and rewiring the circuit with all new wires.