Car doesn't start always always low on voltage.

[7mgte_supra]

To start off, i swapped a JDM motor with the head rebuilt and after the swap the car is having a hard time starting. Only way to start it is by push starting, but when you try to start it, you'll hear the ecu "click".. But once it starts I can turn off the car and if i try starting it, it well fire up fine.. When it's cold or the weather is cold it starts better than when it's hot..Does anyone know what I need to do? I have a apexi turbo timer and it's showing low voltage and when i accelerate the voltage/battery goes down instead of being charged. HELP! If I can't get my car working right probably going to sell it and say good bye to the mk3 world... =(

Parts I've replaced
Starter
Alternator
coolant water sensor to ecu

 

[sneakypete]

if there isnt enough voltage to start the car... it clearly wont start. your problem most likely lies in the wiring. could be a bad ground, or to much strain on your charging system. im no expert tho. i would check to see if you have the correct alternator part number.
what is the voltage reading with the key on but car not running? and what is the voltage reading before you shut off the car?

 

[7mgte_supra]

well when it starts it's at 14.3 but then once car gets hot and i start driving the voltage well drop to 13.3 and then sometimes if i turn on light and others it well go down to like 12.3 or a little higher or lower..

 

[IwantMKIII]

i would suspect bad battery

 

[7mgte_supra]

battery was replace not to long ago.. i got new battery like last august.. or so

 

[sneakypete]

battery was replace not to long ago.. i got new battery like last august.. or so

was the car sitting over the winter or any long period of time?
-pete

 

[Supraboy89]

well when it starts it's at 14.3 but then once car gets hot and i start driving the voltage well drop to 13.3 and then sometimes if i turn on light and others it well go down to like 12.3 or a little higher or lower..

thats normal

 

[7mgte_supra]

was the car sitting over the winter or any long period of time?
-pete

noo it's my DD..

 

[7mgte_supra]

thats normal

As i was told, yes it is normal but my car dont even start...you just get a click click..from the edu..

 

[supra90turbo]

I would do a voltage test on the battery as well as a load test.

It's not impossible that you've got a bad battery. Defects aren't unheard of. You could have a bad cell, I say have someone check it out. It certainly can't hurt.

 

[sneakypete]

just for shits and giggles, have someone wiggle your cps connector while you trying to start the car and see if that does anything.
-pete

 

[7mgte_supra]

just for shits and giggles, have someone wiggle your cps connector while you trying to start the car and see if that does anything.
-pete

It's not that, i've done that... If the cps wires aren't having a good connect, the car would at least crank and try to fire up.. But im having clicks from my ecu.. and no crank..just clicks as if starters was dead..but there's no click from starter..and im on the 4th starter..

 

[suprabad]

First off the click your hearing is the circuit open relay in the right kick panel, not the ECM.

I would not be surprised if the problem you are experiencing is being caused by the starter signal wire. This wire has a tendency to become corroded (probably starting at the connection to the starter and working it's way back). The corrosion results in high resistance that prevents the electric signal that triggers your starter relay and kazzam...no start.

It's usually a semi-intermittent condition and will occasionally work (usually after cold start up, but seems to also fail when engine is hot). Measure your voltage where the signal start wire plugs into the starter and if you find a substantial drop in voltage compared to the battery terminals...then this is more than likely your problem.

 

[7mgte_supra]

thanks i well try that suprabad..