Runs better with battery unhooked

[ckiesman]

Exactly as the title says. Recently I swapped the motor out of my aspire to put it in my festiva. This one really gets me. The car runs better with the battery unhooked. It idles smother and dosent seem to miss-fire. When the battery is hooked up, it seems as if its running on a few cylinders, the main fuseable link starts smoking, and the car dies. I tried replacing it with a cartridge fuse out of my aspire, but no luck, it just blew it. What would cause this? The alt. is out of the aspire, as well as the battery, and that ran great.

any ideas?

[91mcnasty]

You've got a short somewhere

[Pu241]

2X 91mcnasty

Hunt it down before you fry something, if its not too late.

[ckiesman]

ive been hunting, but nothing yet. I checked all the grounds. There arnt to many other wires that i had to move around. What would be my best bet though? something in the charging circuit since it only happens when running, or should i look into something else?

[91_festy_Gl]

When you hook the battery up does everything like lights and stuff go dim or do they get bright? Im gonna guess they go dim since the idle drops and staggers with the bat hooked up. Im leaning more towards a voltage regulator. Not sure if its in the ECU or alt, but if its in the alt then thats all that might need replaced.


Are you using the festiva ECU or the aspire one? If your using the aspire alt with the festiva ECU then maybe thats causing a problem? Not sure why it would but I guess its possible?

[ckiesman]

i am using the aspire alt. with the festiva ECU. The alt. was also confirmed good, as it came out of the aspire working, but as soon as it went in my festy, i had problems.I havent tried my lights, but that does make sense. I will check them out tomorrow.

[DrMaxwellEdison]

I've never had a problem with my Aspire alternator on my Festy ECU

[Christ]

Are you certain the battery is good, and fully charged?

Check that the + and - are clean and fastened properly, and that the B+ and alt charge line aren't touching anything.

I'm banking on a bad connection or the battery being juiced. Internal short in the battery.

[Pu241]

Yeah, I think Christ (never thought I'd be typing that particular word) has a point.
Bad battery
Easy check!

[Basement_Modder]

Put a DP-ST >10A throw switch inside wired between the terminals and the fuses to disconnect the battery. Mount a mini 12v 2A float charger under the hood and plug it in nightly. To start, flip switch on, crank it, flip switch off. Simple and 100% effective.

[Pu241]

Put a DP-ST >10A throw switch inside wired between the terminals and the fuses to disconnect the battery. Mount a mini 12v 2A float charger under the hood and plug it in nightly. To start, flip switch on, crank it, flip switch off. Simple and 100% effective.

Please explain how that is going to help, if the battery is internally shorted?

[Basement_Modder]

It would be charged nightly, connected by the switch, started, and disconnected by the switch (both terminals).

[econoaddict]

I would unhook the big wire from the alternator, wrap with tape to be sure it won't accidentally ground out, then start the car and see if the problem is still there.
Sounds like you have a wire wrong or maybe pinched one on install and it is direct grounded.

I would skip rigging in the switch, trouble shoot and figure out the problem, don't mask it over your just asking for future trouble.

[91_festy_Gl]

Id get a multi meter and check the voltage at the terminals without the battery and see what the alt is charging at. Id also use the multi meter and see what voltage the bat. has.

You could also go as far as checking the voltage at the main fuse without the battery and then with the battery to determine voltage spikes or drops.

Check the wiring to the starter aswell. The main current runs through that and continues throughout the rest of the system. Possible something is grounding there.

[Pu241]

It would be charged nightly, connected by the switch, started, and disconnected by the switch (both terminals).

You will fry the regulator by running the ALT without the battery connected for extended lengths of time.
Check the battery, if faulty, replace.
100% effective and a proper repair!