1994 Explorer Pinging

My '94 Explorer pings horribly whenever I put regular octane gas in it.
The pinging is worst when I accelerate. I've been putting premium gas
in it and that helps quite a bit, but it still pings whenever I
accelerate into a stiff wind. I've changed spark plugs, wires, air
filter and fuel filter. Nothing seems to help. My mechanic says that
the vehicle doesn't need premium gas, but it sure seems to run a lot
better on it. Any help or suggestions would be appreciated.

"Vern" > wrote in message
ups.com...
> My '94 Explorer pings horribly whenever I put regular octane gas in it.
> The pinging is worst when I accelerate. I've been putting premium gas
> in it and that helps quite a bit, but it still pings whenever I
> accelerate into a stiff wind. I've changed spark plugs, wires, air
> filter and fuel filter. Nothing seems to help. My mechanic says that
> the vehicle doesn't need premium gas, but it sure seems to run a lot
> better on it. Any help or suggestions would be appreciated.
>

Cleaning your MAF sensor and the other one on the throttle body may help a
little. How many miles do you have on it? Are you hearding any rattling
from inside the engine? When my '92 with about 265,000 miles on it started
pinging it turned out that the timing chain was loose and had jumped two
teeth. This seems to be very unusual for the 4.0 engine so I would rule out
everything else before tearing off the timing cover.

I have the same symptoms on my '96. I believe the consensus is that its
likely to be an intake manifold gasket leak. I haven't yet got round to
undertaking this project so can't comment on whether this fixes it or not.


"Vern" > wrote in message
ups.com...
> My '94 Explorer pings horribly whenever I put regular octane gas in it.
> The pinging is worst when I accelerate. I've been putting premium gas
> in it and that helps quite a bit, but it still pings whenever I
> accelerate into a stiff wind. I've changed spark plugs, wires, air
> filter and fuel filter. Nothing seems to help. My mechanic says that
> the vehicle doesn't need premium gas, but it sure seems to run a lot
> better on it. Any help or suggestions would be appreciated.
>

I've got about 180,000kms on it. I only hope mine last to 265,000
miles!

Cleaning the MAF sensor cured my '94 of this problem.


Vern wrote:
> My '94 Explorer pings horribly whenever I put regular octane gas in it.
> The pinging is worst when I accelerate. I've been putting premium gas
> in it and that helps quite a bit, but it still pings whenever I
> accelerate into a stiff wind. I've changed spark plugs, wires, air
> filter and fuel filter. Nothing seems to help. My mechanic says that
> the vehicle doesn't need premium gas, but it sure seems to run a lot
> better on it. Any help or suggestions would be appreciated.
>

On Thu, 24 Nov 2005 08:57:06 -0800, Bob > wrote:

>Cleaning the MAF sensor cured my '94 of this problem.
>
>

Same on my 92. I used to have to put premium in it in the hot summer
months to stop it from pinging. Then I cleaned the MAF and have not
had to use premium since.


>Vern wrote:
>> My '94 Explorer pings horribly whenever I put regular octane gas in it.
>> The pinging is worst when I accelerate. I've been putting premium gas
>> in it and that helps quite a bit, but it still pings whenever I
>> accelerate into a stiff wind. I've changed spark plugs, wires, air
>> filter and fuel filter. Nothing seems to help. My mechanic says that
>> the vehicle doesn't need premium gas, but it sure seems to run a lot
>> better on it. Any help or suggestions would be appreciated.
>>

Vern wrote:
> My '94 Explorer pings horribly whenever I put regular octane gas in it.
> The pinging is worst when I accelerate. I've been putting premium gas
> in it and that helps quite a bit, but it still pings whenever I
> accelerate into a stiff wind. I've changed spark plugs, wires, air
> filter and fuel filter. Nothing seems to help. My mechanic says that
> the vehicle doesn't need premium gas, but it sure seems to run a lot
> better on it. Any help or suggestions would be appreciated.

There's the "remove the shorting bar" fix, which retards the spark 3
degrees:

"The bar was easy to find, it's in the passenger side of the engine
compartment behind the diagnostic connection block. Look for a
wire with a connector on the end taped to the large harnass leading
into the block. The shorting bar is a small grey rectangular cube
that plugs into the connector. I just grasped onto it and pulled."

There is also de-carbonizing. Carbon builds up in the head and on the
intake valves, effectively increasing the compression ratio and making
little glow plugs if the carbon gets red hot. Both of those things can
cause pre-ignition or pinging. I read an old post by guru Jim Warman
about adding a small amount of water to the intake of the engine as it
idles, "steam cleaning" the carbon out. There are also kits of
chemicals that do the same thing.

Search this newsgroup or the web for "pinging" "shorting bar" etc if
you need more detail.
-Paul

In article . com>,
Vern > wrote:
>My '94 Explorer pings horribly whenever I put regular octane gas in it.
> The pinging is worst when I accelerate. I've been putting premium gas
>in it and that helps quite a bit, but it still pings whenever I
>accelerate into a stiff wind. I've changed spark plugs, wires, air
>filter and fuel filter. Nothing seems to help. My mechanic says that
>the vehicle doesn't need premium gas, but it sure seems to run a lot
>better on it. Any help or suggestions would be appreciated.
>

Your engine is designed to run on 87 octane gas, so don't use premium.
Regular use of premium tends to build up deposits and cause the
pinging, according to posters in this newsgroup in the past.

Try some of the suggestions others have posted to get it to stop
pinging. Maybe Jim Warman will have some suggestions too.

I put over 100k miles on my 94 using regular gas and it never pinged.


--
Mike Iglesias Email:
University of California, Irvine phone: 949-824-6926
Network & Academic Computing Services FAX: 949-824-2069

same here i clean it twice a year and notice much better performance and gas
mileage
"Bob" > wrote in message
...
> Cleaning the MAF sensor cured my '94 of this problem.
>
>
> Vern wrote:
>> My '94 Explorer pings horribly whenever I put regular octane gas in it.
>> The pinging is worst when I accelerate. I've been putting premium gas
>> in it and that helps quite a bit, but it still pings whenever I
>> accelerate into a stiff wind. I've changed spark plugs, wires, air
>> filter and fuel filter. Nothing seems to help. My mechanic says that
>> the vehicle doesn't need premium gas, but it sure seems to run a lot
>> better on it. Any help or suggestions would be appreciated.
>>

Could you tell me where exactly the MAF sensor is located? Thanks to
everyone who responded to my question. I've searched for "pinging" on
the rest of this group and have found a ton of information. Thanks
again.