ITSWILL

iTrader: (12)

If I have my lights,wipers, and hvac fan on my voltage drops significantly (about 2 to 3 volts) and the car will start to spit and sputter under load. Also once i turn these items off the voltage goes right back up to about 14 volts. I have checked over the charging system diagram in the fsm but cant seem to figure out where the problem is.

I have tried replacing the alternator with a used unit I got off the forum. I got a double pulley as well in case the belt was slipping or something.

Oh and sometimes it will do it with just the lights off.

At first I was assuming that the coil wasn't firing but since I got a wideband I can see that it is actually going lean when it does this, so I am guessing the injectors are cutting out due to low voltage for some reason.

Either way, Im pretty sure if I fix the voltage drop issue it should be good.

Im going out cruising with a chick Im interested in on Saturday night so I really need to fix this so I dont look like a tard. Any help would be appreciated.


Also I replaced the battery with an optima red top which didn't help either.

jackhild59

iTrader: (7)

Ok, what power draws do you have other than the items mentioned. Do you have an electric fan? If so, this could be the source of your problem. If you do and it is a two speed fan, try using the low speed instead of the high speed.

Is the Double pulley an underdrive pulley?

You replaced your old alt with another old used alt. They could both be on the verge of failure. I had a 'reman' that tested good at Oriellies, but acted just like your alt is acting. Get it tested at a shop where they can chart the actual output, not just whether it charges or not.

My testing shows that the rotary requires about 20 amps output to merely run at fast idle. The mhvac adds easily another 15 amps. Lights etc and you could be nearly 45 amps. If that alt is weak but working, it will act exactly like this.

Check your battery cables. If the terminals are a little corroded, this can lead to voltage fluctuations. Get a battery terminal brush and make those babies shine.


What about a bad battery? A weak battery might contribute.

Good luck with the girl.

ITSWILL

iTrader: (12)

I don't have an e-fan or an underdrive pulley.

All my connections are clean.

Battery is new.

Im thinking i just got two bad alternators, wouldn't be the first time it has happened, especially with a used alternator.

Im going to order another alternator from NAPA and in the meantime double check the w/b and b/w wires on the back of the alternator.

Thanks

ITSWILL

iTrader: (12)

NAPA didn't have it, but advance auto does. Hope it works.

Any other ideas just in case?

BolognaBlake

How do your battery cables, cables to the alternator, and ground look?

Replacing all those cables with fresh 1/0 gauge cable would make a wold of difference.

Rx-7fetish

Just went and bought an s5 alt for my s4, this will be the first new alt i have ever owned lol those suckers aint cheap

BolognaBlake

Also, you could pull the alternator off and take it to Autozone or Advanced and get it tested.

ITSWILL

iTrader: (12)

They are old but they are still good, but i know they could be better so I think Ill replace them anyway.

ITSWILL

iTrader: (12)

I know it works, but to what capacity is the question.

I have had stuff tested there in a pinch before and I don't think they can test the amperage it can create, but i will ask.

Mr.LD

i got the same problems with my AE except w/o the jittering and etc. Just low charging #s w/ the lights on. i've done similar things also , red top 35 new custom alt 140amp supposively new / cleaned grounds.

still knocking on my head somewhat. I thought about adding a relay to a battery source when key on + to add more voltage to my wire. From my testing it worked for 2mins before i got tired of keeping my power probe on the wire. Just not too sure if its ok for about 30mins+.

I'll find out if i wanna try it out w/ a circuit breaker so i dont blow **** / fire.

LD

V8what?!

Repair or replace the engine grounds. Let's face it; your car is still using 20 year old wires. It needs fresh grounds in order to work right. Here's the write-up:
http://www.aaroncake.net/rx-7/grounding.htm

ITSWILL

iTrader: (12)

Well the alternator fixed the voltage issue and I thought it fixed the sputtering issue as well, but after driving it for a couple hours tonight it started doing it again.

It does it when there is more load on the engine like when going up a steep hill, the afrs lean way out and it sputters.

cozmosland

iTrader: (1)

i have the same issue, it runs fine for maybe 10 min then the voltage slowly drops and it runs like ****. and this is during the day. at night i never see anywhere near 14 on the meter and i know normally it's suppose to be at 14 or slightly higher on the gauge.
i have an 90 gxl with an fd alt.

wvumtnbkr

I recently had the same symptoms. My problem was a TPS that was going bad. I checked the output of the TPS and it was fine the first time I checked it, but I checked it several times (pushing and releasing the plunger) and every so often it would read an open circuit.

I replaced the TPS and Bam, back to working!


How did the date with the chick go?

Man Law: PICS OR GTFO!

ITSWILL

iTrader: (12)

Yeah I haven't driven the car in a while, but I'm fairly certain the TPS is the problem.

I'm going with a full standalone and will replace all the major sensors anyway.

As for the chick, she never showed up. She had some weird voicemail about how she was sick of it all and breaking contact with everyone for a while. So that kinda threw up a crazy flag and I haven't bothered trying to contact her.

She liked Hondas anyway.

wvumtnbkr

Excellent post!

Well Played Sir!

50 forum points to you.

S4GXL

^^lol 50 life points for sure. thats usually a smart move outside the arpanet

cozmosland

iTrader: (1)

drama!!! lol