OK, Now what????

I just posted a topic called my (90 accord idles rough when stopping), I
drove the fuel down low and filled 3/4 up of Amoco ultimate or 92 octane
for those who don't know what Amoco ultimate is, now the problems seem to
be gone is there a gas tank or fuel pump problem when the tank gets low
has anyone heard of this before? read both articles to better understand
please!!!! Any ideas????????

 

You know, when engines get old, they carbon up. The carbon takes space
in the combustion chamber so, your effective compression ratio is higher
than stock. What this means is some older engines require more octane to
keep from pinging. Are you hearing pinging when you accelerate hard
(with regular gas)? You also get carbon on the back of the intake valves
that absorbs some of the fuel injected into the engine making a lean
(too much air) mixture.

Dirty fuel injectors and induction system are the most common cause of
rough idle. Carbon buildup is next.

I'd run a can of BG44K through it and see what happens. That's what I
use anyway.

When's the last time you changed the fuel filter? Honda says change the
fuel filter when the car can't maintain normal fuel pressure. That means
a dirty filter makes the car run lean.

 

Hard to say.

Could be the fuel pump is sucking filth as the tank runs near empty.

Could be the higher octane is assisting a weak spark, due to a weak coil.

Can you give a maintenance history on this car? And answer the other
questions asked?

Otherwise, don't expect a response...

 

Fuel pumps get their cooling by being immersed in fuel. When they get
older, sometimes the pump's bearings seize up when they heat up - they
obviously heat up more when the fuel level is low.
It could be an indication that your pump is getting tired. Keep the
tank near 1/2 full (or 1/2 empty, depending on what kind of person you
are and you should be ok.

Remco

 

You know that fuel pumps always suck from the same place whether the tank
is full or empty right (in a Honda anyway)? In the tank, it's bolted to an
arm that holds the pump and a sock (well it looks like one) to the bottom
of the tank so, the pickup point never moves.

I like the "overheating fuel pump" thing though. I never thought of that.