Can a new fuel filter do this?? Wow!!!

[shillier]

Could my old gas filter be the source of the poor performance I've been experiencing for so long? For months I've been trying to troubleshoot bucking and hesitation problems that I've had but could never figure out.

Wow... I just came back from a drive after replacing that old fuel filter and let me tell you... what a difference. The bucking and hesitation that I've been experiencing is pretty much gone. I was out for more then an hour and I can't believe the difference. It pulls like crazy all the way to the red line with out any problem and no hesitation. I still can't believe it. What a difference! Could my new fuel filter have solved the problem? I can't wait to dive it again tomorrow!!

Cheers!

Shayne
'81 SC

[KNS]

How long had the old one been in there? I've certainly heard of it making a difference.

[bigchillcar]

typically what happens with dirty fuel filters: the car sits overnight..all the grit which has accumlated in the filter settles..you start the car and it runs..everything is fine..drive it a little while and the grit starts moving around and gets into your fuel flow resulting in intermittent cutting-out sysmptoms. you stop the car..it settles again..start driving and everything is fine..after a while it starts up again as the sediment begins to get stirred up.

sounds like it solved your problem? change it every 10k miles and your 25 year old car/gas tank will be happy.
ryan

[Wayne 962]

Yes, clogged filters can cause these problems - I know first hand!

-Wayne

[911pcars]

It might be a good idea to check the contents of the gas tank. Could be more than 93 octance in there.

Sherwood

[indigowhale]

I've been having this exact problem and will try a new filter. Will report back if it is true. I replaced everything else more expensive already.

[kepperly]

Speaking of 93 octane, does anyone still have access to the good stuff?

KEITH EPPERLY 87 SLANT NOSE TURBO LOOK CARRERA CABRIOLET

[Rot 911]

All the BP stations around here have 93 octane.

[beepbeep]

If your SC doesn't ping then hi octane fuel is waste of money.

There are no knock-sensors to detect and adjust firing. Thus no extra power from higher octane.

[Vipergrün]

Originally posted by beepbeep
If your SC doesn't ping then hi octane fuel is waste of money.

There are no knock-sensors to detect and adjust firing. Thus no extra power from higher octane.

Yes, but you can also advance your timing, richen the mixture, etc, which will give you an improvement. The higher octane fuel will allow you to set a more aggressive advance without the fears of detonation.....

[nhromyak]

Of course you can get detonation (and early parts failure) without the ability to HEAR the pinging...

[makaio]

Originally posted by kepperly
Speaking of 93 octane, does anyone still have access to the good stuff?

Not here in Kalifornia at conventional fuel stations.

[indigowhale]

Went to the parts store and got a Bosch fuel filter. Installed it Friday and found out the old one was installed backwards. Got the new one on and went out and the car hesitated and bucked worse than ever.

Next day I drove the car on a hot day for about 100 miles. After an initial hesitation, the problem has been completely gone. At the same time, I added some gas line dryer which I think was inconsequential. So, many thanks for posting you fuel filter experience. Now the real test will be how long before the hesitation and bucking returns. So far, so good! and the car is running like a "top". I have put about 250 miles by now.

[RickM]

Sunoco has the high octane stuff here....92 or 93 I believe.

[Hugh R]

I believe I'll put one in tonight that I've had for a while. Changed it about 15k miles ago.

[Steve@Rennsport]

Originally posted by beepbeep
If your SC doesn't ping then hi octane fuel is waste of money.

If you rely on your ears as the defacto "knock sensors", then you are in for big (expensive) trouble,...

One never hears the kind of detonation that breaks rings into pieces.

Detonation thresholds are NOT static in air-cooled engines and change with outside air temperatures and engine load.

[john walker's workshop]

when i find a clogged filter in the course of doing a tuneup, i know the customer will think i did an awesome job. a lot of them feel heavy and when you drain them, they just dribble.

[indigowhale]

Now for the cold report, mid 60s this morning and a little hesitation starting out around 2000 RPM but nothing like before.

I think a few turns of the AFM air bi-pass screw to enrich the mix may fix that.

Can someone confirm that turning in the screw on the AFM will enrich the mix by sending more air on the flap and through the main chamber enriching the mix?

After this, the only alternative may be a new DME chip.

[cookbart]

Shillier

Where is the fuel filter of a 92 safari located ?

[Steve@Rennsport]

Originally posted by nhromyak
Of course you can get detonation (and early parts failure) without the ability to HEAR the pinging...

Absolutely true!

One must remember that detonation thresholds in air-cooled engine are NOT static,...they change with outside air temps and engine load.

You'd not believe how many SC & Carrera engines arrive with broken rings where the owner never heard a thing.

Using one's ears as the defacto "knock-sensors" can be very very expensive. Higher octane fuel is much cheaper than buying lots of expensive engine parts.