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low fuel pressure


flames_187

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First my setup: tial BOV, Intercooler, ms2 stock, fuel pump(about 3 yrs old), FPR (1yr old), and stock boost.

I am looking for some input on a problem I am having. Ever since I moved from NC to Indy my fuel pressure at been lower (45PSI to now 35PSI tapering down to 30PSI). Once in a while I get the 45psi like I useto but by the time I look back its down to 35-30psi. I left my fuel pressure regulator (FPR) open to the atm and let tune my MS2 for the difference but now at 30PSI I am getting the dreaded misfire at all rpm (even idle). I tried reconnecting the hose from the FPR to the intake manifold but that just drops the pressure even more. I tried my spare FPR regulator and I get the same results.

Before I moved I did install my IC and BOV and only got to drive it twice. It was lean up top (which it should) but in the lower rpms no misfires.

Things I tried so far:

1. Change plug gap from .41 to .36

2. swapped FPR

3. check timing with timing light

4. uploaded my last known good tune (MS2)

Im pretty sure this is a Fuel Problem but wanted to get input as to other things to check before I run and buy a Walbaro and/or adjustable FPR. I am only running 7PSI and right now only shooting for 10PSI which the stock system should be able to handle. One thing to add is that the car was not started since I moved (2 months). I

Thanks guys!

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One thing you can check is your fuel filter. I have had problems in the past with the stock tank which had crud in it. As fuel was flowing the filter would begin to collect crap in it until it became badly clogged then fuel pressure would die off...If you turned the car off the crud would make its way back from the filter (would be more likely with a screen type filter) to the tank and upon startup again the process would repeat itself with the filter gradually clogging up. Change the filter and make sure the tank is free of debris..just a thought.

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Well drew looks like you hit the nail on the head...pics tell a 1000 words...as soon as I took apart the fuel filter gas came gushing out (was prepared with catch can and towels)...The fuel filter still feels like there is a ton of gunk in it so I know that the gas tank needs a look over.. The gas that came out the fuel rail was clean so that was a good sign that little if any got through the filter, I hope my fuel pump is ok…

 

I am going to drain the tank and search to see how people clean their lines. My idea is to disconnect lines from the fuel pump run clean gas from the engine bay and stick an air hose on the end and do that a couple of times. Once the winter comes I will take the tank down and get it redone. I wanted to get a sump tank installed anyway.

 

dfes0l.jpg

 

166izx5.jpg

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Looks like you have quite a bit of crap in the tank. Its a pain but you really should take care of the crud in the tank or you will be back in the same situation very quickly. Might also have a look at the filter screens in the injectors...fuel filters are good but some small crud will get past...been there...done that. Good luck!!

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thanks for information guys...

I drained the gas tank and didnt find much. The hole is prolly to small to get a good idea of whats inside.

 

I will look up how to take these injectors apart. I never actually done one so it will be good practice. Thankfully this all happened before i put on my supra injectors. If the screens look clean I'll clean the fuel lines and run some injector cleaner as a temp fix until winter when i planned on getting the tank redone.

 

I'll post up how the injectors look...

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Just an update:

I took my fuel rail off and checked out the injectors..everything seemed to be in order...

My idle AFR is still rich (12.2ish) and my on load is still lean(15ish) but i should be able to tune it better...

 

I did have to change my spark plugs because i fouled them throughout the process...

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