FAQ: Fuel Filters

If it's half as good as your steak write-up, I'll be happy!

its a PITA i remeber doing mine on the riviera. i said numerous curse words

its pretty easy, but like corey said its a pita when its rusted on there.

Chicken wrote:

Oldsman....Did you put on the Chevy Tahoe filter? How did it work out for you?

I am currently running pig rich... at idle at light throttle. I think it was a little to much with my fuel pump and 42.5 injectors.

I don't see how the fuel filter can have any affect on running too rich. The filter does not control fueling, unless it is plugged up and doesn't allow enough thru, resulting in running lean.

Are we talking about oil filters or fuel filters here?

Fuel...

So what is the reasoning behind using a Tahoe fuel filter on a Riv?

They're talking about the flex fuel Tahoe filter, supposed to flow much more. IMO, it doesn't matter unless your engine is highly modded and needs more fuel than the OEM filter will flow.

I went to Advanced Auto and did a side by side comparison...unless the parts guy pulled the wrong filter, the tahoe filter wasn't even close in appearance....

Riv, female connection in, male connection out
Tahoe, female connection in, female connection out...

I didnt get the micron ratings....

So i was looking at the part numbers for fuel filters as they relate from the 95 riv to the other years, as well as the ones from the GTP. They all seemed to be the same:
95:
WIX Part # 33311

97 Riv:
WIX Part # 33311

97 GTP:
WIX Part # 33311

So, when I was getting a supercharger coupler, i added one of these guys:
http://www.wbodystore.com/grandprix/high-volume-fuel-filter-p-258.html

The thing is, when I went to put it on the car, i noticed that the flow direction is backwards to the one thats on the Riv right now. The output for the one ON the riv right now is the threaded end. Flowing towards the engine. The output on this guy from WBS is the thin end with the snap in gasket thing. So if i installed it in the car, the fuel would be running through the filter backwards. Whats with this? is that what makes the WBS "High volume filter" supposedly flow well? cause its not flowing the right way? As far as i can tell from pics of the PROPER filter, the output should be the threaded end. Do I have this wrong?

It's a flex fuel vehicle filter, and it has been documented as being backwards as far as normal flow is concerned. I've read a lot on the topic elsewhere. I doubt you need a hi flow filter. In fact, ZZP told me not to bother using theirs unless I was highly modded.

I do NOT know what the implications are for running reverse flow.

I didn't figure I really needed it either, but it was cheap.. and i was looking for things to double up on my shipping with. Anyone know if its ok to run then? Or of any sites I could read about it?
Besides these, which are all i can find:
http://www.regalgs.org/forum/viewtopic.php?f=18&t=50118&st=0&sk=t&sd=a
https://rivperformance.editboard.com/care-maintenance-f8/fuel-filters-t2479-45.htm

well, i guess they say its ok:

from WBS:
Hi Andrew. There are no ill effects to running the filter like this. It's actually quite common.

Mike Kopstain

On Mon, Oct 6, 2008 at 9:55 AM, Andrew Rogers <> wrote:

Hi,
I recently purchased your High Volume Fuel Filter [WBS-HVF] and had a quick question. For the way this filter mounts, the flow direction is backwards. I have heard that this is normal for putting the flex fuel filter onto these cars, but my question is what effect that would have on the flow? is there not something in the filter to prevent back flow or flow in the wrong direction? have people been running these with no trouble in the backwards direction?

-Andrew

You'd think there's a GOOD reason for the flow direction to be marked on the filters though...

no kidding...
edit:
hrm... the Wix site lists this filter (33623) as a full flow type, so who knows, Ill give it a try...

Doesn't give a max gpm flow rate though. The filter spec'd for our cars shows a 1gpm max flow rate, and filters down to 17 microns. The full flow filters down to 12 microns, which seems to me would flow LESS. Dunno....

Hey Dave

Whether the full flow filter flows less depends on area of the filter.

Up to a certain point you can increase the flow and decrease the particle size that's trapped by changing to a finer filtering media but at the same time increasing the surface are of filtration. For a given size filter can this is done by making the pleats deeper or folding more of them per inch.

Albertj

Yes, that is true. Odd though that the Wix site info omits the GPM rating on their "full flow" filter.

Still not finding any solid information regarding a backwards installation of a filter that has flow direction arrows on the can.

I emailed Wix, asking about using that filter in a reverse flow setup.

1998 Riv wrote:

I emailed Wix, asking about using that filter in a reverse flow setup.

ah, I'm glad I spotted this then, cause I was just about to do the same thing.

Their contact info section doesn't give much hope of a quick response though. (... in the near future...)

So when the fuel coming out of your old filter is brown it probably means it was a good time to change it right?

Coming out of the "out" end after removal? Or coming out of the "in" side?

In side. Is that normal?