1991 Accord--tach goes to "0" when I turn lights or heat on

I have a 1991 Accord with a 5spd F20A SOHC motor that is having problems
today. I woke up to take kids to school and car was dead. Car was not
started for 5 days and my wife said that yesterday she heard the cooling fan
running in the garage. Garage is heated to 55 degrees. So, I jumped the car
and idle was fluctuating and car was running very "choppy". When I hit the
gas, the engine sputtered and back fired through the throttle body. I left
the car running for the 10-15 minutes that it took me to drop off kids in
truck. When I came back, car was idling fine(@850rpms) and running smooth.
I thought it was okay now. I turned it off after another 10 mins and went
back inside. Now, I started it and went to work and everything seemed okay.
When I went to go to lunch, battery was almost dead (laboring to turn over)
so I let it run for a few minutes, then as I was about to pull off, I turned
on the lights and the tach dropped to "0" like the car stalled but it was
still running. When I hit the gas it was sputtering and back firing. I
turned the lights off and the tach went back to normal. I turned the heat on
and the tach went back to "0". Hopefully I will be able to limp the car the
6 miles to get home without getting pulled over for no head lights.

Any input is greatly appreciated.

 

The fucking thing is 17 years old. That's what happens with cars that
old. Get rid of it, and get something newer. Duh.

 

--------------------------

Disconnect the battery for 20 seconds so everything can reboot. You have
a few ghosts in the machine. Then do an 'idle learn procedure, if things
don't return to perfect:

http://www.hondasuv.com/members/showthread.php?t=5061&highlight=idle+learn+procedure

'Curly'

 

The thermosensor that controls the cooling fan is faulty. The fan
won't be on at 55 degrees!!
Your battery was wrecked by that stupid fan. And when the battery
can't maintain proper voltage, the ECU is confused.
So reset it (pull a fuse if your car has one, or simply disconnect the
battery) then start the engine and let it idle for 10 minutes. Do not
press the gas pedal during this process.
But fix the sensor and replace the battery as soon as you can.

 

My 91 Accord runs fine. Why get rid of something that gets me where I
want to go?

 

Because before very long, it will NOT get you where you want to go, and
you'll be stranded, probably at a most inconvenient time.

That's one reason.

 

Do you work for a dealership?

How long have you been reading at this newsgroup?

Hondas need not be abandoned until the engine has given up
the ghost.

 

A couple of years.

Which is exactly what I'm talking about above.

 

Some electrical part likely has given up the ghost.

Until the piston rings fail or similar, the engine is fine.

 

Some people first resort to the "throw money at the problem" practice
than think rationally.

I drive two old Civics, (1982 'n '83) that have no 'puter, PCV valve,
oxygen sensor etc and get a minimum of 35mpg. Best of all, no payments
or high insurance costs.

I may not be stylin' but I've got more moolah in my wallet!

JT

 

<giggle>

With proper maintenance, Hondas (outside the rustbelt) can be made to
run practically forever.

Get a fricken' clue or do you like being a sheeple?

JT

 

....and even then, there are alternatives than high payments and plastic
cars...

JT

 

Oops. I forgot that low mileage used Honda engines (shipped
from Japan) are available for under $900 in the U.S.

 

Today I went and warranteed the battery for a brand new one and put it in.
The car started right away with no problem. Idle still fluctuating (1200-
2000) and gradually made its way down to 850 rpms when it was at operating
temperature. After the initial start I took off the battery terminals and let
the car warm up on just the alternator to check if the alternator was bad.
When the car was warm and at a steady idle I tried turning it off,
reconnecting the battery and starting it again. Started fine and idled fine,
I disconnected battery again and tried turning on the lights and the car shut
off. Now, I reconnected the battery and started it again, this time when I
took off the terminals the car died instantly and the lights weren't even on.
The alternator is only a year old and I bought it new. Could the alternator
be shot already? And would the alernator cause the tach to drop to "0" while
the car is still running? I also put in the VSS that I had bought a few
weeks ago when the speedo was jumping and tach still dies when I turn the
lights on. Also, fyi, the check engine light didn't come on.

 

You need to take the car to a facility that can properly determine if
the alternator is working.

And find a mechanic that knows what he is doing.

Jeff

 

If this is an actual Honda alternator, it is pretty unusual to see a failure
this soon. If this is a Chinese rebuilt from AutoZone or the like, its a
surprise that it worked this long.

 

Wild conjecture on your part.

When you're walking down the shoulder of the road in a pouring rainstorm,
and your broke-down car is a mile behind you, how much difference does it
make if "some electrical part" has malfunctioned, or the goddam crankshaft
is broken? Either fucking way you're walking down the shoulder of the
road, in the rain.

 

As can any other car, if you're willing to do it.

I've got clues enough for the both of us, Gramps. What the **** is a
sheeple?

 

It's "irrational" to want to drive a car less than 20 years old? Is that
what you really think?

I don't care about MPG, or payments, or insurance. I can afford all of
them. I own 5 vehicles (one Honda which is an 07 Accord), and all are
less than 3 years old.

Are you sure? Wanna bet?

 

oh no! you're not supposed to let the engine running on the alternator
to test it!!!