Stopping Pinging 1993 Ranger

There were some posts on this problem several months ago for Explorers and
Rangers running into pinging problems. Also, I have a 91 2.3L Ranger that
ran into the same problems over the past few months.

It turns out that Ford put an 'octane shorting bar' in the wiring harness.
When it is removed, the computer will retard the timing to stop the pinging.

I removed mine and the pinging stopped. Power also dropped slightly, which
I notice with the 2.3L, but you probably won't notice with the 4.0L.

The computer seems to be adjusting its settings over time, because right
after I pulled this jumper, I couldn't get the engine to ping at all, but
now it will ping if lugged. The power drop also seems to be less than it
was at first.

The speculation in this group was that Ford wouldn't tell anyone about this
feature because the engine was not emissions certified for operation with
the octane shorting bar removed, and Ford could get into big trouble if they
advised people to take this thing out.

On my Ranger, the octane shorting bar was a grey plug in a two-wire socket
which came out of the wiring harness a few inches before the EEC test port.
That, in turn, is on the right fender just behind the power distribution box.

I have the Haynes manual for the Ranger (which I find very useful, BTW), and
it calls this thing the 'EEC shorting bar' in the engine wiring diagram.
The Haynes manual for the Explorer calls it the 'octane shorting bar'. As
there are several of these jumpers in the engine compartment, it might be
worth looking for the manual to get the wire color codes just to make sure
you're pulling the right one.

In my case, my Ranger uses perhaps half a quart of oil in 5,000 miles of
highway driving, so oil blow-by is not likely the culprit.

Also, since the 93 Ranger is still under warranty, I would give Ford the
opportunity to correct the problem first. However, no one who complained of
pinging in posts on this subject said Ford was able to do more than tell
them to use premium gas.

Best of luck,
­---
Tim Nye "Duct Tape: The handyman's secret weapon"
University of Waterloo - Steve Smith, aka Red Green

I have a 93 explorer with the 4.0L engine and it pinged for years until the engine light finally came on. The code said the MAF sensor was bad. Since replacing it, it hasn't pinged once. Shop diagnoses, $70. New MAF sensor from auto parts store, $70 with old one traded in. The sensor can apparently under perform for years without turning on engine light, causing a lean fuel mixture condition. this in turn will cause the fuel to pre-ignite and make it ping, as well as surging on acceleration and increased exhaust gas temps wich can crack your cyl heads and burn up your muffler.

My '88 Ranger uses (consumes, not leaks) about a quart in 3000 miles. Is
this enough to cause pinging? If it weren't such a pain, I would have
retarded the timing already - that blasted hold-down bolt is almost
impossible to get to :-(.

- les

--
Les Bartel Spec: Specification or Speculation???
Intergraph Corporation
Electronics Division

(205) 730-8537

: In <3a33ug$@gondor.sdsu.edu
: : : on why
: : gas! I
: : so any
: :
: Debi:
:
: My explorer (same engine) started pinging this spring on regular
: fuel. It only pinged lightly. After I changed the air filter, the
: pinging went away. I still need premium when towing my boat, but for
: normal driving 87 octane regular is fine. I think the dirty air filter
: affected the computer calibration enough to do this. At least it is a
: cheap thing to try, and it worked for me.
:
: Larry

check the EGR system operation. It's by far the most common cause of
spark knock in cars today. If it doesn't work, the car WILL ping. The
valve and passages get clogged with carbon (normal) and are supposed to
be cleaned every 30K miles. No one does it, though, and the first problem
you notice is ping. Have the system checked and that will probably fix
your problem.
Charlie Kaiser

In <3a33ug$@gondor.sdsu.edu writes:

Debi:

My explorer (same engine) started pinging this spring on regular
fuel. It only pinged lightly. After I changed the air filter, the
pinging went away. I still need premium when towing my boat, but for
normal driving 87 octane regular is fine. I think the dirty air filter
affected the computer calibration enough to do this. At least it is a
cheap thing to try, and it worked for me.

Larry

That is possible. If your filter was dirty enough, the computer would sense
a lack of air flow, and lean the mixture. This leaning would cause excess
heat, and thus detonation (pinging, knocking).

As I mentioned to Debi via email, the most common cause of this with older/
high milege Fords is oil blow by. Ford's piston rings are trash, and
all it takes is a little oil to lower the octane level of the gas.
Oil could also seep through intake valve guides, causing the same problems.

As you have shown though, it could be a number of problems.

Steve