Issues with burning up Alternators on my Single Turbo 2JZ-GTE

[MKIV]

i purchased a '94 MKIV that has been converted to single turbo. the car was sitting for about 5 years and was not running when I purchased it but was told that it had been running before it was put into storage. I found that the ethanol in the fuel take and rotted the fuel lines. I replace the fuel lines and the battery and the motor cranked. Problem is we can only run it till the battery dies. I replaced the alternator now twice and both of them have the same issue, the alternator keeps on dying. Anyone have any ideas as to what may be causing it?
Specs:
Greddy T78 single turbo
Greddy Intercooler
PowerHouse Racing upgraded fuel rail, lines, dual fuel pumps, upgraded injectors
AEM (v1) EMS
AEM ignition
NGK Iridium spark plugs
Apexi boost controller

no ICE, just a regular head unit and some upgraded speakers, but no additional amp and subs.

thanks!

 

[hvyman]

Battery fully charged?

What kind of alternator? Cheap one from autozone? Get a oem one. Cheap alternators suck.

 

[MKIV]

Battery was fully charged each time as i have a battery charger that i leave it on. The replacements alternator was also a factory Toyota 90 amp NEW alternator that we got from a dealer. I am hoping its not a wiring issue. Thanks

 

[Radial]

Might sound incredibly silly answer, but have to give it a shot:
"keeps on dying".... does it ever charge at all? Or does it just stop charging after a while? Measure the battery voltage before you start the car, and after the car is running.... if its 13+volts with engine running it's charging... if not, ye... you know the drill.
Stock wiring on most JZ's have 100-150A Atlernator-fuse to protect from shortage in wiring/Alternator..... make sure it's intact.

I'm thinking you are lacking the +12v to the magnetic field on the generator... its one of the small wires in the alternator-connector. It activates through Ignition switched power-source.
No 12v there makes the magnetic field in the generator too small, and no real power output form generator (less then 8-9volts or so, no charge at all).

 

[MKIV]

thanks for the suggestion. i tested it and when i first install it, w/o the engine on, the battery is around 12v, actually above it, about 12.7v. then with the engine running, it's 14.3v. voltage was measured using a volt meter and via my greddy turbo timer. i'm sure the alternator is good when i put it in but once i start running around town with it, and i'm not even pushing the car, at some point, i see the voltage drop below 12v, around 11.7 and never go above that.

i don't know if it a wiring issue somewhere in my car or what. this is really frustrating but i'm glad i'm able to get some help and assistance here.

 

[Radial]

read this article man.... especially about the S-port, and try a new wire directly from the battery (via fuse of course) to the S-port... take it for a spin.

http://wilbo666.pbworks.com/w/page/39441708/Toyota Alternators

Good luck

 

[MKIV]

Thank you! That's the first I've seen of that. I am going to try that as well as the "big three" upgrade and upgrade my grounds. Will come back with feedback once all the work is done.

 

[dirosa]

my buddy burned up 4 alternators on his s13 back when we first started doing swaps, and it proved to bad cable from the alternator to the battery. guess it was too loose causing excessive resistance that was backfeeding into the alternator and frying them after a few days.

 

[MKIV]

well here's an update: I took off the alternator to get it fixed at a dealer because he said it's repairable. apparently, the diodes are getting burnt out almost immediately. he fixed it and tested it on his machine right away, it sparked and then failed. so the replacement alternator is bad and it may be the culprit, i don't know yet till he gets me another replacement for that. he will fix my original alternator for me as well, so i'll have a spare, just in case. i still intend to upgrade the wire from the alternator to the battery to a 4 gauge wire and then upgrade my grounds as well, with either 8 gauge or 4 gauge. i also think i'm going to switch to a gel cell battery as well as change out the connect to the alternator from the wiring harness.

thanks for all the suggestions!