so last night i was driving to work, and i was reading over 16 volts. i thought that was very odd. when i left i noticed that my subs wouldnt hit or anything (still reading high). after getting home i realized that my headlights weren't working at all. checked the fuses, everything was good. then today i went to start it up and see what would happen. well it started, but still reading 16 volts and i drove it maybe 100 feet and the car just died. it will turn over very quickly but it will not start. its not flooded (have a fuel cut off switch). the motor was rebuilt 3k ago. my first problem since .

any suggestions?

 

How old is the alt? Best first guess is that the voltage reg fried, and/or the diode bridge in the reg is shot. Try another alt.

Hopefully you didn't fry any PCB's...

 

well, i spent all afternoon workin on my car. and now my face matches my beautiful red seven, anywhoo. i checked and shes getting fire. i noticed that i wasnt getting any fuel to the motor, so i put in an old fuel pump i had lying around. a couple minutes later she fired up perfect and ran. i shut her off and started her back up--no problem. then she just died. now she won't start again. i've pretty much exhausted my knowledge on what to do with her. i have no clue how old the alternator is...i should find out. just wish she'd start.

 

the electrical system in the FC is designed for a peak 15.5 volts. If it really was at or above 16 volts you could have fried all kinds of things including the headlight bulbs and ECU

 

Where did you see this 16 volts, anyway? On your stock gauge in the cluster?

If you can get her running again, you need to put a good meter on the battery terminals and get a better idea of what your system voltage really is with the alt on line...

Is the plug on the back of the alt in good shape???

 

yeah, the 16 volts was what i saw on my stock gauge...i dont have a voltimeter handy...i might go try and pick one up. the plug on the back of the alt looks like its still in decent shape. i was curious about the fact that i may have fried my ecu...lets hope thats not it.

 

hhmm when i fried my ecu i couldnt get any spark.... here try this test method to test your ecu.... Pull off the connector to the pressure/boost sensor, with your voltmeter connect the (+) to the brown/white wire going in that harness, and the (-) to a really good ground (I used the engine UIM). After turning the key to ON you should see 4.5 to 5.0 volts on that wire. If not then you are going to need a new ECU.

 

ONCE AGAIN..... THATS ME somebody didnt log off

christopher

 

if my ecu was indeed fried, would the car have run fine without any problems for 5 minutes? and then i was able to turn it off and start her up again no problems, but then she just died. tried to work on it a little while ago, but its too dark. smelling fuel when i crank it, so i might try the atf trick...who knows maybe its somethign stupid like shes flooded. argh.

 

so i went back out to work on the car today. tried the ATF trick, just in case. ehh didnt work. but i pulled the fuel lines to the motor and had someone crank the car. no fuel at all. i changed the fuel pump, checked the fuses...not sure where to go now. arrghhh this car is a great shop teacher haha

 

Go back to the basics, get your fuel going, check for spark, etc...

If you'd like to delve further into checking the ECU out, try this:

https://www.rx7club.com/showthread.p...leshooting+ECU