Block off steel return fuel line. Any suggestions?

[Blayze]

I’m trying to test fuel pressure on a Chevy S10 2.2L Flex Fuel

the fuel lines are all hard lines leaving no good place to easily pinch off the return line.

the fittings are 5/16 and 3/8 quick connects.

anyone with a good idea on how to isolate the fuel tank from the fuel rail?
seems that all auto parts store near me do not carry any fuel fittings that I can use to rig anything up.

Topic

[Blayze]

2000 Chevy S10 2.2L MFI Flex Fuel 2wd

I have low fuel pressure and am unable to find out why.

With key on engine off I have about 10 psi
engine on I have about 18 psi

with key off fuel pressure is lost instantly back to 0 psi

New fuel filter.
No external leaks from fuel lines.
Replaced fuel pump same results.
Removed fuel rail to check out the injectors and am unable to see any leaking.
The fuel pressure regulator is apart of the fuel filter which is new.

So wtf?

any ideas or suggestions?

[college man]

you may need to go under the truck to find a rubber hose section.

[college man]

Is it possible the connections are reversed? see if this helps.
You can take the reading right at the filter/regulator.

http://www.fuelpumpu.com/news-2000-03-chevy-s10-22l-tech-tip.aspx

[Blayze]

the connections are two different sizes, cannot be reversed. theyre quick connect style and i cannot find any hardware to hookup to it. To test or block off the return etc.
any ideas? or anywhere i could find the hardware?
autozone and oreillys have proven useless

I’m about to try a new fuel filter and see if that corrects the problem(New Filter installed was a Pronto). doubt it but maybe.
I’v also pulled the fuel rail to watch the fuel injectors for leaks. None found everything looks dry at the nozzle and the outlet at the fuel rail.

I’v checked every inch of fuel line for leaks, found none.

With key turned on I jumped the fuel pump relay to stay running during all “diagnostics”
Pump only goes up to ~10psi. With key in off position all fuel pressure is lost instantly back to 0psi
I installed an Airtex fuel pump new from autozone, could this possibly be bad? Could my filter/regulator be bad?

idk so many questions so few answers, im about to start searching for fuel leaks with a lighter…

[Andrew]

My initial thought is that the new fuel pump is bad, as it should be putting out more pressure than that and have an internal check valve to prevent pressure loss – warranty claim?

Before you get too excited, how about checking voltage at the pump connections while it’s running?

Secondly, are you sure there are no flexible return lines to clamp off? It seems strange there aren’t as the engine has to move about a little relative to the fuel tank. What if you disconnect the return line quick connect and fit the test guage – is that not effectively blanking the return line?

[Bill]

The fuel system uses a computer controlled fuel pressure regulator and the pressure is based on the MAP sensor output. I don’t know if deadheading the return line will accomplish much but you can check out this website for the fitting you need. It’s a Dorman part that should be easy to obtain. You will need a piece of bulk fuel injection hose and some good clamps to adapt it and something to plug the end of the hose (5/16 bolt).

You will need something to read a PDF file (adobe reader free) to view it.

http://www.dormanproducts.com/documents4rb/135-145quickdisconnectbuyersguide.pdf

[Blayze]

I was questioning the new fuel pump also it being an “Airtex” from AutoZone.

However it turned out to be the new fuel filter/regulator that was installed. Brand name “Proto”
Installed a “Duralast” filter/regulator, turned the key pressure shot up to around 60psi. Turned the key off, pressure dropped a few lbs and held.

If I could of had the correct hardware/fittings to tap into the fuel line, I would of been able to find the problem a whole lot faster and with a lot less headache.

Lesson of the day? idk, test test test and when you cant test anymore start replacing shit…

lol
now with my fuel rail and throttle body out of the way I can get after that bad valve cover leak, maybe this was meant to be.

[college man]

Sounds like good progress to me. 🙂

[Blayze]

thats a very good link. I downloaded the pdf for future reference.

While I was getting my filter from AutoZone the guys there let me borrow a few fittings from their loan-a-tool kit, on the honor code that I’d bring it back. A three way splitter,(two ends being male barb fittings, & the other end a shrader valve), some rubber hose & a few compression fittings. Plan was to cut into my steel fuel line and make a place to attach the test contraption then simply compression fitting it back together.

Didn’t need to use them after installing the filter but it was nice to have and a kind gesture that I will return with my business to them.

[Blayze]

Any progress is good progress I suppose B)

[quote=”college man” post=118805]Sounds like good progress to me. :)[/quote]

[Blayze]

checked compression recently, 165 psi in all cylinders. So that’s good.

Was questioning the ECM, so I removed it and placed it inside overnight. Reinstalled it with dielectric grease the next day. Still cold temp outside but fired right up on second crank.

I’m wondering… did the ECM get reset from being unplugged and solve my problems? Are there any loose connections or solder spots that may be breaking from shrinking in the cold? Was there moisture in the connectors that I cleaned up?

If it starts tomorrow after sitting in the cold overnight, I’ll have more information.

Has anyone experienced similar problems or know of any regarding the ECM and its failures?

[Blayze]

woops, i posted that last reply in the wrong thread :blush:
ment to go in “Cold Weather Crank No Start” thread I posted

[Author]

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