About Us

James408 · 02-24-2014, 11:27 PM

Hey guys just checking back in on my progress with my 69 Firebird 400. Was having issues with my car falling on it face in second gear from fuel starvation. Updated the old nasty fuel lines with new stainless 3/8 fuel line to a Robbmc 550 pump and a Robbmc 1/2 inch sending unit(no sock) and an adapter to go from 1/2 inch hose to 3/8. Running a 40 micron Robbmc fuel filter before carb and was running a 100 micron Robbmc fuel filter before the pump. was still falling on its face. After a suggestion by a member here I took off the pre filter to the pump and HELLO! Im pulling HARD through all three gears and no clattering. Wanna thank Darby for the advice.

HWYSTR455 · 02-25-2014, 07:12 AM

The 100 micron was a restriction? Hm, one wouldn't think so, it should have worked. Did you happen to call RobbMC and mention that fact?

.

David Jones · 02-25-2014, 09:03 AM

Don't you need some sort of "strainer" before the pump?

66bonne · 02-25-2014, 10:01 AM

I have the RobbMc filter before the pump and no fuel issues at all.

Jim

David Jones · 02-25-2014, 10:30 AM

I have the small (150gph) RobbMc 100 micron before my pump also. I got rid of the sock (what was left....) and installed the RobbMc just outside the tank.

James408 · 02-25-2014, 12:02 PM

I here ya guys but this filter was causing me to stall just driving normal. My try a diff brand but since I have a new tank and pickup so not real concerned about big chunks messing up my mechanical pump

RobbMc · 02-25-2014, 02:06 PM

Very strange. Any chance you got the 40 micron and 100 micron filters swapped somehow?
If you bought both of them from us at the same time, I usually put a RobbMc decal on the 40 micron filter so you can easily tell them apart.
Also, did you check the filter after you removed it? Could it be full of debris? Even a new system can have a surprising amount of when you first run gas through it.

James408 · 02-25-2014, 04:16 PM

No it's not the 40. It has no decal. I'll check filter tonight.

James408 · 02-25-2014, 04:40 PM

Just FYI I had that 100 filter on my car for just a few 100 miles before all the new fuel line and tank and sensing unit upgrades because I wasn't sure if my old sock was any good. When I pulled the old sending unit the sock was in great shape. I just don't see how I could have filled up a 100 micron filter so fast. Before reinstalling with the new tank and sender. I could blow easily through the filter. And the car fell on its face in second gear first run.

James408 · 02-25-2014, 08:54 PM

Ok pulled the element out and did not look black or dirty.

mchell · 02-25-2014, 08:59 PM

I am not running a pre filter......never have....haven't killed a pump yet...knock on wood

Ideal? probably not........I don't have fuel delivery issues as witnessed by watching video of fuel pressure through the 1/4.....tank is not sumped....1/2 tank of fuel seems to do the trick...no less

James408 · 02-25-2014, 09:23 PM

Oh yeah I know its not ideal but will work I'm not that worried about it this point. Just tickled that my car pulls hard through all the gears

Hey Robb is it possible you guys put the wrong filter element in filter case?

Tim Corcoran · 02-26-2014, 11:59 AM

From the factory all they had was a sock in the fuel tank and a filter in front of the carb and it worked pretty good.

RobbMc · 02-26-2014, 12:45 PM

Quote:

Originally Posted by Tim Corcoran

From the factory all they had was a sock in the fuel tank and a filter in front of the carb and it worked pretty good.

The 100 micron filter is intended to be used instead of the sock in the tank. The RobbMc sending units do not have a sock.
Some kind of prefilter or sock needs to be used. We get several pumps back every year that aren't pumping correctly because one or more valves is being held open by a piece of debris stuck in a valve.

RobbMc · 02-26-2014, 12:58 PM

Quote:

Originally Posted by James408

Oh yeah I know its not ideal but will work I'm not that worried about it this point. Just tickled that my car pulls hard through all the gears

Hey Robb is it possible you guys put the wrong filter element in filter case?

Anything is possible but it is unlikely. Besides, unless your engine is right at the limit of the system (550 horsepower), even a 40 micron filter would not cause a problem when the filter is brand new. Only after the filter has been run for a while (and the small pores start to get full) would it become a restriction.
My guess is that one of the two fittings on the filter was not sealing completely and was allowing air to be sucked into the system.
Have you ever tried to suck a cola through a straw with a hole in the straw?

James408 · 02-26-2014, 01:57 PM

Quote:

Originally Posted by RobbMc

The 100 micron filter is intended to be used instead of the sock in the tank. The RobbMc sending units do not have a sock.
Some kind of prefilter or sock needs to be used. We get several pumps back every year that aren't pumping correctly because one or more valves is being held open by a piece of debris stuck in a valve.

Yes I already know this Robb, and I ordered your 100 micron filter for this reason. Maybe my fuel needs are right on the edge where any restriction before the pump is too much.
but for some reason its not working. as far as the fittings sealing I have them on tight with thread sealer. Now I was running a 3/8 npt to 1/2 inch barb on the inlet and 3/8 barb on the out. If that makes a difference since I'm going from 1/2 inch sender to 3/8 fuel line.

No way I'm making over 450 horse.

RobbMc · 02-26-2014, 02:05 PM

Well, I'm stumped. Maybe the pump is not working 100% right. When you don't need the pump for a week, ship it to us and we'll flow it and examine it internally.