I'd fix it before modding something that's broken?
I'd fix it before modding something that's broken?
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
Ha ! I just happened to hop on the site after an absence that spanned from my last post until now pretty much. If you're running the Walbro and it's producing 10psi on the stock unmolested regulator then you MAY have enough of a fuel demand and also probably a broken regulator spring that will not "overload" the return passages in the TBI unit itself. I would recommend a little checking on the FPR and the fuel filter (if not new) just as an added safety measure. IF all is well and you are still getting 10psi, then I would go ahead and modify the FPR and bump the pressure a little. I forget now which injectors you decided to go with for now, but if using the 454 units I wouldn't exceed 13psi as you don't need the fuel. If you are running the 350 units, I would probably go with a max of 18psi. GM used to offer 18psi springs for performance use so I would think that you are good up to that. I've run as much as 30psi and have heard of use up to near 50psi, but cannot vouch for the reliability and consistency at those pressures. Before my recent L31 swap, my 200k+ mile L03 was so inconsistent in every way that I couldn't/wouldn't verify any issues related to injectors although it ran "fine" when removed.
I am running the 454 injectors. The 10 pounds is sitting at idle, I did not drive the truck so I do not think that the demand of the engine would come in to play yet. This was just a test late last night after installing the tank. I knew something had to be wrong after reading your last post, about how much fuel pressure you were getting. 10 pounds with this pump is just crazy. There has to be a problem somewhere else. I will pull the injector pod off tonight and take a look. Either way I still plan on modding the regulator.
-1999 Hugger Orange SS, LS2 402 T56, 9 inch Ford 3.90 gears, Tuned with HP Tuners
-2002 Cavalier, Tuned with HP Tuners
-1994 Full Size Blazer ,383 TBI 4L60E, 4.10's, Tuned with Tunerpro RT (Where it all began)
Something is wrong with only 10 PSI? Could even be the gauge?
AFPR on top of 454 injectors will handle a HUGE amount of HP. Does your motor really need this much fuel? Only reason for it is engine needs more fuel at WOT. If you don't need it tuning will be harder...
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
I know its within the normal range but I would still like to check the regulator. I was expecting at least 13. I have a gauge with a smaller range. the one on there now goes from 0 to like 50 I think. I have one that goes from 0 to 15. I swapped it out to the 0 to 50 gauge thinking it was going to shoot up over 15 psi.Originally Posted by EagleMark
-1999 Hugger Orange SS, LS2 402 T56, 9 inch Ford 3.90 gears, Tuned with HP Tuners
-2002 Cavalier, Tuned with HP Tuners
-1994 Full Size Blazer ,383 TBI 4L60E, 4.10's, Tuned with Tunerpro RT (Where it all began)
Well you know 0 to 15 gauge would be more accurate for a pressure in that range. I agree, have to find out why pressure is wrong before contiuing.
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
That bedliner paint job looks awesome by the way. Can't wait to ride over and see it in person.
They are nice fuel pressure liquid filled gauges from Jegs, but yes I agree the other gauge would be better. I will swap them back out and recheck. But, you do agree that 10 pounds is to low?
555-41010.jpg
This is the one thats in there now.
555-41012.jpg
Last edited by 96lt4c4; 07-24-2012 at 10:45 PM.
-1999 Hugger Orange SS, LS2 402 T56, 9 inch Ford 3.90 gears, Tuned with HP Tuners
-2002 Cavalier, Tuned with HP Tuners
-1994 Full Size Blazer ,383 TBI 4L60E, 4.10's, Tuned with Tunerpro RT (Where it all began)
Yes 10 PSI is to low. Even if you don't need the extra fuel the spray patteren atomization is better ar 13 to 15.
I've used that gauge without issues hot or cold. Some say pressure drop on gauge when hot? I wouldn't trust a gauge like that did that and think I had a fuel pressure issue?
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
Between the atomization and the fact that with the fuel pump that he's running should be taxing the regulator a little I would expect/like to see a higher reading than that. With those gauges, however, I would want to check with a dedicated test gauge that has a much larger face and is meant to be pretty accurate and reliable. If it is verified that 10psi is a true reading then I would be looking for an issue. One of the reasons that I haven't bothered to lower my pressures any is that I prefer to run E85 and it has a higher density and vapor point than gas so I liked having the extra pressure to help with atomization especially in colder temps.
Well found a couple things. I pulled the pod to check the reg. and found that the little metal plate on top of the diaphragm that seals to the body of the top injector plate had a groove worn in it. The would explain why the truck does not hold fuel pressure after it is shut off. I had a spare pod so I checked it and it was in good shape but I noticed there was a little difference in the reg. The spare had a stiffer taller spring. So, I used spare pod and reg. Fired her up and still 10 pounds on the 60 pound gauge. So I swapped to the 15 pound gauge and it is showing 14 pounds now. I may mod the extra reg. housing and make it adjustable.
-1999 Hugger Orange SS, LS2 402 T56, 9 inch Ford 3.90 gears, Tuned with HP Tuners
-2002 Cavalier, Tuned with HP Tuners
-1994 Full Size Blazer ,383 TBI 4L60E, 4.10's, Tuned with Tunerpro RT (Where it all began)
Here is a picture of what I found with the diaphragm. At least I know now it will seal off better and not bleed fuel off when the truck is off. I was going to take a pic of the difference in the regulator springs but didnt. Now I have 14 psi fuel pressure too so thats good.
Here is what the pile looks like, trying to get it back on the road. Its been apart for over a year. I sprayed it with U-Pol Raptor tintable bedliner.
Last edited by 96lt4c4; 07-25-2012 at 04:07 PM.
-1999 Hugger Orange SS, LS2 402 T56, 9 inch Ford 3.90 gears, Tuned with HP Tuners
-2002 Cavalier, Tuned with HP Tuners
-1994 Full Size Blazer ,383 TBI 4L60E, 4.10's, Tuned with Tunerpro RT (Where it all began)
I wonder if that other spring is from the later year BB with higher pressure?
Is that a Camaro SS hood scoop I see?
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
Thats my other toy...I wonder if that other spring is from the later year BB with higher pressure?
Is that a Camaro SS hood scoop I see?
1 of 375 Hugger Orange SS's built in 1999. 27K miles. LS1 6 Speed. HOSS
-1999 Hugger Orange SS, LS2 402 T56, 9 inch Ford 3.90 gears, Tuned with HP Tuners
-2002 Cavalier, Tuned with HP Tuners
-1994 Full Size Blazer ,383 TBI 4L60E, 4.10's, Tuned with Tunerpro RT (Where it all began)
Nice!
I'm looking at one, not sure if it's Hugger Orange by photo, think it's red? Look at my other thread and let me know what to look for on these cars...
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
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