AINT SKEERED

iTrader: (2)

Saving this thread to refer back when I do my fuel pump

dlandsvZ28

Since you have already paid for it, I would notify shipper/vendor and request that they send it rather than a refund. Be aware you have seven days to report the shortage. Make sure to save the inventory list with check mark on each item as it was picked, packed, and shipped.

The ground cable is not a show stopper. A good redundant ground is dependent on a lot variables - essentially how good are all current grounds. This particular ground connection is in the engine bay, but there still might be some rust under the retaining nut. So make sure all rust is removed.

You can make your own but their ground cable is quite inexpensive compared to making one.

You can use the current bolt to connect or if there is an extra hole like mine (a 98 and yours is a 2000) then you can insert a bolt there and connect as well. You will have to remove the fender well splash shield. Not sure if I would want to use a self tapping bolt because it might strip out when clamping. You want a good connection that will not loosen over time.



hth

Dano 00TA

Guess I'm gonna need the c5 regulator after all. Had it running and saw pressure was at about 67lbs

Ok, I've read people have been running this pressure and it's been ok but I was thinking wouldn't this cause it to run rich since the injectors will flow more at a higher pressure? Or will the computer learn and lean them out?

Drj8787

Dano 00TA

So you don't think I'll need another tune then? I guess since I'm taking it to my tuner to get a nitrous tune, I can let him know about the pump change and he can adjust it if necessary.

Drj8787

Dano 00TA

Yeah, I think I will just to be safe. and like you said, gotta keep the pump happy.

dlandsvZ28

Which pump did you install - 255, 340, 450 ?

I didn't have any luck with the C5 kit. With the Racetronix RXP341 (340 lph) the C5 filter would not hold pressure at 58 lbs. At idle I was getting 71-75 lbs of pressure measured with a gauge and with a mechanical gauge off of the stock rail. So the readings IMO were accurate. Others have reported similar results. But Racetronix pretty much said that from the get go and why IMO they don't provide a kit for a 340. They do sell a fuel regulator, lines, and rails pkg, however, which will handle the 340 and more. I have that kit now and a 340.

But I am not blaming anyone. I didn't do enough research. Learn as you go. Since I have a Procharger, I needed a boost referenced regulator for more fuel when in boost.

So unless IMO someone can guarantee 58.lbs of pressure with the C5 filter (if the pump is more than a 255), I would opt for a regulator and return line.

Plumbing the return line is pretty easy and/or opting to use the feed line connected to the return line aft of the filter to return fuel to the tank and then use 6an or 8an line connected to the stock feed line just ahead of the stock filter (or aftermarket) and on up to the stock rails. It will cost more, but in the long run, less if you eventually want to go to a bigger pump etc.

With gasoline, 6 AN line is good to 800-1000 rwhp (note gasoline not e85). 8 AN PTFE(Teflon) fuel line is extremely stiff and much harder to navigate it out of the engine bay and then do a 90 degree back to the pump.

Dano 00TA

dlandsvZ28

This is a direct quote from Racetronix

"Facts:
Delphi changed the bulkhead connector in their modules from a 150-series to a 280-series type b/c if chronic failures. The 150-series terminals are rated at 14-amps max. at room temp This rating goes down with temp and age. The 280-series terminals are rated at 28-amps. 340LPH pumps typically draw 12-14 amps @ 58PSI @ 13.5V which places this wiring/terminals right at their upper current limits.
When using a Walbro 255LPH pump a pressure rise will occur with the factory regulator configuration. This is b/c the regulator and return flow path is too small/restrictive to handle the pump's flow. Typical pressure at part throttle/idle will be 60-63 PSI vs. the factory set 58PSI. The pressure may drop once the pump/fuel warms up and the vehicle voltage drops. This pressure rise is not as pronounced without a hot wire kit b/c the voltage drop in the factory harness will reduce pump flow/performance.
Running a 340LPH pump with the factory return system may cause premature pump failure b/c of excessive head pressures created. In-house testing here has proven this and that is why we have not offered a F99 340LPH solution yet. Once we are able to offer a complete system which eliminates this restriction we will."

I don't know about the 99-2002 model years, but on the 98 fuel pump module the hard return line inlet into the fuel module bulkhead is 5/16 instead of 3/8 like the feed line. So IMO doesn't make much sense to run 6 AN line all the way to the bulkhead only to pinch/reduce the return hard 3/8 inlet line down to 5/16 inch. So I cut the 5/16 inch end off of the 3/8 hard line and added a 3/8 male end to the line. The 6 AN return line from the tank can be connected to the male end either with a female hose end or a 3/8 quick connect hose end. I now have 6 AN - 3/8 line all the way from the regulator to the tank.

Note also: the return outlet from the C5 filter is 5/16 inch and connects to 5/16 inch line all the way to the tank (98 for sure - don't know about 99-2002 models).

Dano 00TA

"Running a 340LPH pump with the factory return system may cause premature pump failure b/c of excessive head pressures created. In-house testing here has proven this and that is why we have not offered a F99 340LPH solution yet. Once we are able to offer a complete system which eliminates this restriction we will."

So I'm assuming I just installed the wrong pump for the factory lines? I sure hope not

dlandsvZ28

Your pump is ok. It's how you regulate and maintain 58 psi that is the issue.

According to Racetronix it depends whether your return line is 3/8 or 5/16 and starts at the filter or from the rails. On my 98 the return line from the t block just ahead of the stock fuel filter is 5/16. The feed line is 3/8.

The return line inlet to the tank on the 99 -2002 looks as if it is 3/8 - hard to tell from pics.

Your feed line is 3/8 or 6 AN and is sufficient. Six AN or 3/8 inch return line is sufficient at your hp levels from the rail.

IMO the critical question and answer. Is the C5 filter/regulator adequate to maintain 58 lbs of pressure and NO more or will the 340 or higher capacity pumps overpower it? Racetronix has responded several times about this issue. My post above with their remarks is one of them.

IMO if Racetronix thought it is OK - they would for sure sell a kit. But appears they don't want to be accountable for premature failure because of the stock regulator. Or for those who have 98's where the bulkhead connector is not adequate for 17 amps at 70 lbs either. When under boosted conditions in order to maintain pressure and volume it can raise to 70 psi. With a boost referenced regulator the pressure ramps up when under boost so the 340 draws more amps at 13.5 volts.

Your bulkhead connector is NOT an issue for model years 1999-2002 with the upgraded 150/280 bulkhead connector.

BTW - you and I are not the only ones with the C5 filter with pressures over 58 psi. It's why I threw it away a went to a return line with pressure regulator at the rail.

Another forum.

"FWIW! I just had a brand new Aeromotive regulator blow the diaphragm after only 30 minutes of run time. So I switched to the Corvette filter and I'm getting 68-72 psi at idle with a Bosch 044 pump. My readings are from a pressure take off fitting just before the rails (not mounted on engine away from heat), with a liquid filled Aeromotive gauge. I don't know if I'm just over-driving the stock filter regulator or what. Most likely use a fuel transducer and make a table for the fuel pressure variance under load. 70 psi seems kind of high. I've heard of such thing as injector lockup from too high of pressure, but I'm not sure the exact psi a Bosch injector does that." The Bosch 044 is 320lph - a little less than the 340.

Issue is addressed in link below too.

http://www.racetronix.com/RX-C5-FPK-2.html

Looks like Racetronix testing shows that the fbody short return line from the filter rather than the rail is their concern when used with a pump that flows significantly more than a stock pump.

Dano 00TA

Well, (un) luckily the track just announced the end to the race season so I won't be getting any new times since my mods but at least I have time to get this taken care of before next season.

AUS Injection

Trap door is the way to go, makes your life easier.

Dano 00TA

Agreed! In the past I'd never cut my car but now that I did this and realized how much time I saved and the fact that I'll probably be back in there for pressure issues, I'm glad I did it this way.