Fuel Injector testing & replacement

[EXPetrush]

What tool is everyone using to test the fuel rail pressure? Can anyone provide a link to a supplier or can I get that @ any parts store? I have looked into the five0 replacement injectors but has anyone else found other options? There was a discussion months ago about some corvette replacement injectors...

I have a hard start issue, truck won't start without fully depressing gas pedal... new fuel pump, filter & no OBD codes... 100k so figure injectors are the weak link... once truck starts.. there's a poof of fuel laden smoke... then truck runs fine...
Thanks.

 

[DeanBrown3D]

Put a fuel pressure meter (Sears $40) on the shrader valve on the fuel rail and test the pressure and how fast it falls after the pump turns off (a few secs after you put the key in ignition but without starting) . It shoudl not fall for a few minutes (andit shoule read 30-40 psi when running.)

 

[Porter]

I had a strange problem with the same symptoms. I checked the fuel rail and had a loss of pressure before starting, but after a hard start - it would run fine. I removed all the injectors and sent them out. They came back perfect, so I figured it was the pump. So I purchased a new pump, but while I was removing the old one, I found out that the fuel return line has a small flapper valve that a piece of plastic had lodged in it, creating an opening that all the pressure would leak out of.

As for fuel pressure related problems, it can be in no specific order 1) the pump, 2)fuel filter, 3)fuel pressure regulator, 4)injectors.

 

[DeanBrown3D]

Porter - where is that flap you mentioned? Near the pump? Or are you talking about the pressure regulator on the rail?

Thanks

Dean

 

[Porter]

The flap is on the pump inside the fuel tank. But since its already been replaced, I'm not sure it would be the problem (I missed the pump relacement when I read it the first time around).

I would continue along the inspection of the injectors and the fuel pressure. In the morning, before starting press the fuel rail schrader valve, and see if anything comes out. Its a good idea to have a pressure meter, but this will give you a little info on your way to buying the meter.

Have you considered running some injector cleaner through the system? Maybe some seafoam in the fuel tank. Its cheap and worth a quick try before you start tearing into the injectors.

 

[ptschram]

What tool is everyone using to test the fuel rail pressure? Can anyone provide a link to a supplier or can I get that @ any parts store? I have looked into the five0 replacement injectors but has anyone else found other options? There was a discussion months ago about some corvette replacement injectors...

I have a hard start issue, truck won't start without fully depressing gas pedal... new fuel pump, filter & no OBD codes... 100k so figure injectors are the weak link... once truck starts.. there's a poof of fuel laden smoke... then truck runs fine...
Thanks.

First off, your hard start condition is probably due to badly leaking injectors resulting in a horribly rich combustion chamber atmosphere.

As for checking fuel pressure, WW Grainger sells a nifty little gauge. Search for 0-60 psi, 1/8" NPT, back mount process monitoring gauge. Should cost about $6.00. With this, a tee and a close nipple, you can have permanent monitoring and retain the ability to depressurize should you need it. If you are a painfully cheap bastard, you can buy a cheapie tire pressure gauge at Wal-Mart and remove the shiny sleeve and screw into the fuel rail directly-I do not have long-term experience using this gauge as a permanent installation.

I have a fuel pressure gauge mounted on my fuel rail that has been there for several years now.

If you'd like a pic, e-mail me at sales@btlrovers.com

Peace,
PT