Fuel PSI issue...Stumped

[rford426]

So thats good its still there I do have a wideband but it doesn't read while im logging...i dont remeber what it was doing honestly when i wasnt logging

 

[JeremyH]

It would help maintain pressure. Reduces backflow of fuel through the pump when shut the car off etc. When it spiked what did it go to and after the drop how fast and what did it drop to.

 

[rford426]

It spiked to 72 stayed running then dropped to 39-40 then a few seconds later it started dropping dropping then car died @ 9psi

 

[JeremyH]

It spiked to 72 stayed running then dropped to 39-40 then a few seconds later it started dropping

If it drops below 30-40psi while the car is on with the pprv valve then the pumps are moving next to no fuel at this time. So they are either shut off or there is a leak and fuel is going back into the tank.
Did you tighten any hose clamps or anything when you had it out? Maybe you fixed it then it came loose under high pressure again.

What did it drop to psi wise and did the car stall?

 

[Darkness]

Im not sure I know exactly what your talking about???


But I was able to get the car to pressure back up and start up again fuel pressure was good idled fine turned off the car...re started once again everything fine then it spiked up in pressure then started to pressure down and car died like normal....I got all of this on a datalog is there anyway for me to post it here?

The problem I had was when the pins in weather pack were crimped onto the wires some of them didn't have a good connection.

 

[rford426]

Okay guys thanks you so much!!! The car is fixed and back to running again!!!!! It ended up being my FPDM wire upgrade wire off the battery had a bad connection and was haveing some voltage drop!!! All is well now though and car is running! Thanks!

 

[JeremyH]

Should have gone with one of my kits! lol

Glad its fixed Ryan! Looks like it was an intermitent wire issue afterall.

 

[rford426]

^^ No Joke!!! I used a Power wire from a system I had in my last vehicle on the mustang when I had a subwoorfer...Subwoofer was removed 3years ago and never took the wiring out so I just used it for the wire upgrade since it was exactly where I needed it...Might be time to order a new kit from you but I think I fixed any issues in the cable today...Just glad this is all it ended up being and the car is running again...Guess I just needed some more bonding with the locking ring on the fuel hat lol!!!!!

 

[JeremyH]

Yeah me and the locking ring have a real love/hate relationship lol

 

[rford426]

Somehow me and my buddy got it first try today!!!

 

[JeremyH]

Thats usually how it goes, you either get it first try... or you need to grab a snickers lol

 

[rford426]

Hahaha now I need to see why im only seeing 4ps on a 7psi spring...Just gonna throw the 10psi spring in until i can get the EBC working...

 

[JeremyH]

Boost or exhaust leak?

 

[rford426]

Boost or exhaust leak?

Jeremy I had talked to you before bout my low psi... Is it possible I have a leak??? Or is it possible it truly is from getting rid of the exhaust... I figured the wastegate would still not open until it sees 7psi regardless

 

[one eyed willy]

Jeremy I had talked to you before bout my low psi... Is it possible I have a leak??? Or is it possible it truly is from getting rid of the exhaust... I figured the wastegate would still not open until it sees 7psi regardless

Waste gate can be forced open if you have too much back pressure.

You could have a loose coupler on the cold side.

You can check your back pressure by plumbing in a boost gauge to the hot side close to the waste gate or turbo, then use some copper tubing to disapate any heat going to the boost gauge. 2 to 1ratio is OK. 2psi in the exhaust vs 1psi in the cold side.

 

[rford426]

Waste gate can be forced open if you have too much back pressure.

You could have a loose coupler on the cold side.

You can check your back pressure by plumbing in a boost gauge to the hot side close to the waste gate or turbo, then use some copper tubing to disapate any heat going to the boost gauge. 2 to 1ratio is OK. 2psi in the exhaust vs 1psi in the cold side.

I doubt I have too much back pressure being straight down pipe no mufflers

 

[JeremyH]

Where is you boost source for the wastgate?

 

[rford426]

Off the compressor housing...

 

[JeremyH]

An easy test to see if there is a coldside leak is to temporarily move the wastegate source to the manifold and plugging the compressor housing. If there is a small leak in the coldside the turbo will now spin up more to overcome it and reach desired boost read at the manifold. If you get noticeabley more boost why attached to the manifold you know you have a coldside leak. Keep in mind there will be about 1psi difference due to piping volume and intercooler pressure loss from the get go.

 

[one eyed willy]

I doubt I have too much back pressure being straight down pipe no mufflers

It's easy to have too much back pressure before the turbo, depends on the location of the waste gate and the spring you are using..... A light spring will get pushed open by the pressure a lot easier. So if your waste gate has a light spring and is close to the headers, it can be pushed open. Also would have a lot to do with what exhaust housing you are using. I hope it's just a loose cold side coupler, but just throwing it out there....I had a lot of back pressure issues on my original set up I had to get worked out before going with my new set up.

To test the cold side you can buy block off couplers from siliconeintakes.com or make your own and then pressurize it with a air compressor. I recently did mine and found a few issues.......when I was done I had no issues holding 30 psi.the ride afterwards was night and day difference.