Fuel pressure bleeding off. #c10 #sniper

[cruizin01]

Soo, Ill try to make this as short as possible.

 

I built a new fuel system for my C10 to get rid of the FiTech fuel command center and go with a more normal in-tank mounted pump with a returnless feed to my Holley Sniper.

 

I set it up like any other fuel system I've seen.

 

Holley Hydramat mounted to a walbro pump in the tank.

 

I have 2 lines coming out of the tank. 1 supply to the pressure regulator (filter before) and 1 return from the regulator back to the tank. I then have the supply running up to the Sniper with a gauge at the Sniper. As shown below.

 

 

The sniper primes the pump when I key on. But as soon as the pump turns off the fuel pressure bleeds from 58psi to 0psi in about 10 seconds. So I figured this particular Walbro that I had/found/barrowed didn't have a check valve. So I ordered one from Jegs and installed it after the regulator. It does the exact same thing. I took the valve apart and everything seems to function as it should.

 

Here's the valve.

 

https://www.jegs.com/i/JEGS/555/150021/10002/-1?CAWELAID=1710703609&CAGPSPN=pla&CAAGID=54888473260&CATCI=aud-300525381019:pla-457855243156&CATARGETID=230006180040357494&cadevice=c&gclid=CjwKCAiA4OvhBRAjEiwAU2FoJfZswtBvZ2R0uMCUXz647BwKDrpwHxpIV4Tb9EzlUmKW-J9AkgHCqRoC1P4QAvD_BwE

 

 

If I key on but don't start it right away the truck definitely long cranks when the pressure dies off before it can build back up again.

 

I don't know where to go at this point? Im can't think of any good ways to diagnose where or how the fuel is returning back to the tank. Ideas?

[ODoyle]

You can use a https://www.jegs.com/i/JEGS/555/15276/10002/-1 fuel sample valve to ensure you aren't bleeding back at various points in the fuel system. The check valve you are using bleeds off at less than 1DPM (Drip per minute).

 

What does the pressure gauge say at the regulator? What sniper part number is it?

 

Shoot me an email and I can help you. james.flanary@jegs.com

[cruizin01]

You can use a https://www.jegs.com/i/JEGS/555/15276/10002/-1 fuel sample valve to ensure you aren't bleeding back at various points in the fuel system. The check valve you are using bleeds off at less than 1DPM (Drip per minute).

 

What does the pressure gauge say at the regulator? What sniper part number is it?

 

Shoot me an email and I can help you. james.flanary@jegs.com

 

email sent.

[Geeto67]

as a side note, how do you like the holley sniper and the Fi-Tech stuff in general? been thinking about this system for the GTO down the road, the Fi-tech price makes it hard to pass up, but people say the sniper is the better computer/throttle body.

[ODoyle]

Sniper kits are good. FiTech kits are cheaper but tend to have WAYYY longer lead times and sub par technical suppport.

 

Personally, I dont think you get more bang for your buck than with an Edelbrock Pro Flo 4 EFI kit. 35970 is a 550HP max kit that includes the intake, fuel rails, fuel injectors, Throttle Body, Android based controller, wiring and a fully potted ECU

[Geeto67]

Sniper kits are good. FiTech kits are cheaper but tend to have WAYYY longer lead times and sub par technical suppport.

 

Personally, I dont think you get more bang for your buck than with an Edelbrock Pro Flo 4 EFI kit. 35970 is a 550HP max kit that includes the intake, fuel rails, fuel injectors, Throttle Body, Android based controller, wiring and a fully potted ECU

 

Unless I am missing something that's a $2K setup before you upgrade the fuel system. Granted it's port injection rather than throttle body, and it comes with a billet distributor, but that's still a lot. One of the reasons I liked the Fi-tech and Holley is that they can bolt up to the stock spreadbore manifold I have on the car now (which has been ported and port matched but still looks stock).

[ODoyle]

I sell/field issues with these systems every day. Most of the issues I see are from people that aren't very mechanically inclined.

 

The New Fuel Command Center II from Fitech is a great improvement over the original. Their lower cost EFI units dont seem to have many problems but when they do its not something We at JEGS or any retailer is able to handle. You have to talk directly to them and that is not easy. We regularly wait 3-5 days for return emails.

 

We sell the fire out of the sniper kits with inline fuel systems. Not a lot of people are all about the in tank setups due to the level of modification involved with the tank.

 

I am not saying either kit is BAD, what I am saying is for the extra money spent, I feel you get a better Style of EFI as well as better tech support, ALL USA Made product and (as well as with the Holley) All GM sensors so if one does die, you can easily pick it up at advance.

 

In your case with needing one that sits on a stock spreadbore Manifold the Quadrajet Sniper or the GO EFI 400 with the MSD box and G Surge Tank is a better choice.

[cruizin01]

as a side note, how do you like the holley sniper and the Fi-Tech stuff in general? been thinking about this system for the GTO down the road, the Fi-tech price makes it hard to pass up, but people say the sniper is the better computer/throttle body.

 

I haven't had any issues with the actual hardware or software.

 

Its been a lot more work than I initially intended, no fault of Holleys though. Between switching fuel systems and ignition systems its been time consuming.

 

I recently added their hyperspark distributor, coil and module to add timing control to the system. This required a complete rework of the wiring in the engine bay for the most part.

 

I havent' gotten a chance to drive it yet due to the weather.

 

The software seems pretty simple to operate. Ideally Id like to take it to Brian Turner and have to smooth out the tune once I some hours on it. Ill do some on my own just because I can but not having it on a dyno Im just guessing.

 

I like the look of that edelbrock system. Now that its cheaper and knowing what I know I would have seriously considered that instead of my setup.

 

[zeitgeist57]

Coincidentally to this question, I've been watching "Snidertron3000" and Hoonigan...and both of them were using Holley Snipers in their traditional Chevy V8-powered truck projects.

 

How do you have a coolant temp sensor and a fan switch wired up to the FI box? I thought I remembered something affecting the system operation...not sure if that affects the injectors remaining opened to bleed off fuel pressure maybe?

[Geeto67]

 

I am not saying either kit is BAD, what I am saying is for the extra money spent, I feel you get a better Style of EFI as well as better tech support, ALL USA Made product and (as well as with the Holley) All GM sensors so if one does die, you can easily pick it up at advance.

 

In your case with needing one that sits on a stock spreadbore Manifold the Quadrajet Sniper or the GO EFI 400 with the MSD box and G Surge Tank is a better choice.

 

again, sorry for the hijack

 

Well when you put it like that it seems to make sense to spend the extra money - it's a real value to have easy to find sensors, plus actual port fuel injection, an dedicated and calibrated ignition system, and a cpu that can be easily accessed by an android device. I see edlebrock makes a setup for pontiacs so it might just make sense to port match the manifold that comes with it since it's not a big job.

[cruizin01]

Coincidentally to this question, I've been watching "Snidertron3000" and Hoonigan...and both of them were using Holley Snipers in their traditional Chevy V8-powered truck projects.

 

How do you have a coolant temp sensor and a fan switch wired up to the FI box? I thought I remembered something affecting the system operation...not sure if that affects the injectors remaining opened to bleed off fuel pressure maybe?

 

The coolant temp sensor is hardwired to the holley unit. And Im not using their fan control. I have a separate Dakota Digital unit for that. Neither of these to my knowledge could affect my scenario.

[cruizin01]

again, sorry for the hijack

 

Well when you put it like that it seems to make sense to spend the extra money - it's a real value to have easy to find sensors, plus actual port fuel injection, an dedicated and calibrated ignition system, and a cpu that can be easily accessed by an android device. I see edlebrock makes a setup for pontiacs so it might just make sense to port match the manifold that comes with it since it's not a big job.

 

And its not really any extra money compared to the Holley when you add in the cost of the timing control. Its basically the same cost with the added "benefit" of port injection. Even though this typically doesn't make more power..

[cruizin01]

Update:

 

After going back and forth with James and not quite knowing what direction to take I decided to try replacing the "new" fuel pressure regulator. It wasn't an ebay one but it wasn't an Aeromotive either. So I ran to jegs and got an Aeromotive unit to try out.

 

Its 90% fixed!

 

It takes several minutes to bleed off to zero. It does bleed to 40 pretty quickly but then very slowly after that. The pump seems to be able to bounce back a lot quicker as well as soon as I put power to it. Its still weird by the check valve wouldn't hold the pressure in the line even with a junky regulator.

 

I have the worst luck with junky parts right out of the box. Even when I try to buy OEM parts a lot of times I get dead ones.

 

Either way Im satisfied with it for now.

[ODoyle]

If you need to return that check valve, feel free to do so!

[cruizin01]

If you need to return that check valve' date=' feel free to do so![/quote']

 

Im gonna leave it just as a space filler. Otherwise I have to rework everything. Thanks though. And thanks for your emails.

[Geeto67]

have you checked the line and junctions for leaks/weeps? can't be just the check valve can it? from the way you describe it, sounds like there is a weep somewhere in the system that is contributing to the slow drop in pressure.

[cruizin01]

have you checked the line and junctions for leaks/weeps? can't be just the check valve can it? from the way you describe it, sounds like there is a weep somewhere in the system that is contributing to the slow drop in pressure.

 

All the joints in and around the valve and the regulator are dry. There are only a couple others in the whole system. I will double check all these before I get the truck back on the ground but I don't expect to find any leaks. But as I mentioned, the pump has no issue bringing the pressure back up instantly compared to when the fuel was drained out of the system and it had to refill the line.

[99StockGT]

Wow totally missed this thread until now but glad to see it got handled! Having a Jegs crew member on tap for the CR folks is a HUGE benefit too so thanks for the special tech support James!

 

Totally agree with you on the Command Center II from FI tech, many fewer issues with it versus the original one.. no more annoying heat soak issues. The FI Tech kits are great bang for the buck, really damn simple to set up and get wired in as far as the inline setup goes. Unfortunately their parts availability lately has been a bit... shit. Working on a big block mopar project we were doing an intank pump set up for to feed a 600HP FiTech unfortunately... their pumps had a 2 month wait time.

 

So, off to Holley for their in tank returnless setup! A bit more money up front but have rarely ran into issues with them and the extra features the Holley comes with out of the box are great for future PA / Timing control in the future.

[cruizin01]

Totally agree with you on the Command Center II from FI tech, many fewer issues with it versus the original one.. no more annoying heat soak issues.

 

For sure. I didn't do enough research on changing out my existing low pressure parts for a high pressure setup. I thought I was gonna have to buy an expensive FI tank and run new lines, etc.

 

In reality it would have been cheaper to just do this from the start. Hind sight is always pretty clear.

 

I was able to get decent money back on eBay for my fuel command center. I think I had it to the point where it would work well but I just didn't trust it after having it strand me right off the start.

 

btw, I follow your guys' stuff on YT.

[99StockGT]

For sure. I didn't do enough research on changing out my existing low pressure parts for a high pressure setup. I thought I was gonna have to buy an expensive FI tank and run new lines, etc.

 

In reality it would have been cheaper to just do this from the start. Hind sight is always pretty clear.

 

I was able to get decent money back on eBay for my fuel command center. I think I had it to the point where it would work well but I just didn't trust it after having it strand me right off the start.

 

btw, I follow your guys' stuff on YT.

 

We did a FI Tech Command Center setup on a fellow CR members C10 a while back... that thing drove us nuts! Fortunately the pump replacement wasn't a total nightmare but it's really quite annoying taking apart a vehicle you JUST put together and was working fine for a while. FiTech has seen some incredible growth over the past few years and the guys are always extremely nice and supportive but might have out grown their ability to support these days. The in tank pump issue I mentioned cause a .... headache.

 

Having faith in your old ride not leaving you stranded on the side of the road is important. Some of the fun of the drive is taken away when you are constantly terrified something is going to die.

 

And thanks for the follow :fuckyeah:

[cruizin01]

We did a FI Tech Command Center setup on a fellow CR members C10 a while back... that thing drove us nuts! Fortunately the pump replacement wasn't a total nightmare but it's really quite annoying taking apart a vehicle you JUST put together and was working fine for a while. FiTech has seen some incredible growth over the past few years and the guys are always extremely nice and supportive but might have out grown their ability to support these days. The in tank pump issue I mentioned cause a .... headache.

 

 

 

Having faith in your old ride not leaving you stranded on the side of the road is important. Some of the fun of the drive is taken away when you are constantly terrified something is going to die.

 

 

 

And thanks for the follow :fuckyeah:

Oh I felt that right off the bat.

 

The fuel pump died. Stranded me.

 

Then a few weeks later the starter died. Stranded me.

 

Then a couple weeks after that the alternator quit. Luckily i was close to home.

 

I think ive gotten the big bugs works out.. haha

 

Sent from my SM-G930V using Tapatalk

[coltboostin]

To clarify, what issue do you see from it bleeding off? My shot bleeds off int he Hobo. I give zero Fs about it. Car always starts mint and runs like a top.