Snorkelface

In my quest to figure out my severe over fueling, before I send the car off to be dyno tuned again (which it shouldn't need because it's the same pcm they did the tune on), I want to verify I don't have an injector that's leaking or stuck open. I read I can do this by disconnecting the entire fuel rail intact, then turning the key to the "ON" position to prime/pressurize the system and see if any gas comes out (yes, being precautious of the potential spray).

My question is I read that I needed to be sure to unplug some injector plug, but it wasn't specific. Does anyone know what plug, if any, I'd need to disconnect before doing this test?

Jaxem

iTrader: (3)

I can't think of any that you'd need to disconnect, it's not as if the injectors are going to try to open if the engine is running.

My two cents on this isn't probably what you want to hear, but i read the same thing and tried it, couldn't ever get the injectors to all stay in, the pump only primes for a second or two, but one of the buggers would always pop out and fuel would go everywhere...and if you can't test it at normal pressure, i don't see what good it is in checking for leaks

Snorkelface

Thanks for the info.

I thought the LT1 style injectors have clips that keep them engaged on the rails?

hrcslam

Sometimes the clips break off or don't fit when people put new injectors on. If the clips arent there, the injectors will pop off from the pressure.

If thats the case, you'll want to remove each injector and use an air compressor with a hose and bench test them.

If you have the time, send the injectors off for an overhaul.

Snorkelface

So if I can get my hands on an air compressor, would the injector already be closed by default, so if put air behind the injector, if I feel it on the other side it's bad?

Jaxem

iTrader: (3)

If there's clips, that's news to me, mine must have been long gone when i tried to do it

Snorkelface

Before removing the rails, I figured I'd check out what the the fuel pressure does since have a a fuel pressure gauge on my A pillar. When turning the key to ON to prime the system, the pressure jumps to 44PSI, then immediately drops to 31PSI and holds there. I did this about 8 times and it was the exact same result each time. Would that signify I have a leaky or stuck open injector?

And regarding the clips, yes, I have them.

BALLSS

with KOEO the FP should "snap" to 41-46 then drop to around 36-38

31 is "low" but the motor would still run

what is FP with motor running?

does it stay stable under "sustained" WOT or drop? (it should not)

and on the whole pull fuel rail and turn key to see if injector leaks....the FP is not on very long so I don't think this is a valid way of testing.

You can have injectors serviced for around $12 per injector. I used ww.cruzinperformance.com

Snorkelface

I can't run it at WOT. There's so much fuel getting into the motor it doesn't run well and is usually only getting 6 or 7 cylinders actually firing (all are getting spark).

I can start it and rev it, and maybe drive up and down the block a little, but that's about it.

hrcslam

1 or 2 clogged non-flowing injectors would case a rich bogging condition. Did you check that?

Snorkelface

That's what I'm trying to figure out. I'm going to remove the injectors anyway. I didn't realize they were so cheap to just have them checked. I was suggested it could be those, bad O2 sensor or maybe even a bad coolant help sensor causing it to dump fuel in. Either way, I'll eliminate the injectors from the equation.

Snorkelface

At idle it's at about 48PSI. If I rev it, pressure drops to about 40PSI with what seems to be at just one cylinder missing.

hrcslam

Are all the injectors clicking when it's running?

Snorkelface

I can't tell because the car is too loud. No fuel squirted our when I disconnected the rails from the intake and put the key to ON. I guess I'll see what the results are from the injectors testing. :/

hrcslam

I use a mechanics stethoscope. $10 at the local parts store.

Snorkelface

Ahhh, I like that. I'll grab one!

Snorkelface

Btw, I can see why people ditch these injector retainer clips after they take out the injectors for the first time; they're a pain on the azz! Haha

Shownomercy

iTrader: (1)

Have you verified the FPR is not shot?

Snorkelface

I haven't. I can't imagine it would be since an expensive Aeromotive model was added not long ago. How could I test that? Since I'm taking the rails off today, could be easy to do now.

But, if my overall problem is that I'm getting too much fuel info the engine, the FPR going out couldn't cause that, right?

Gojira94

iTrader: (4)

Aeromotive 13107? I know they're like $140.00 and it seems a waste to ditch an expensive part, but if it's a 13107 pull it out and put a stocker back in it. I used one for a while and it began to leak at the brass bung with thread sealer paste on it. Could have burned my car up, some guys' cars have burned up with it.

When a stock regulator fails, the diaphragm inside fails/ perforates and fuel runs into the vacuum line on the passenger side of the intake into the intake fuel/ air charge, adding uncalculated fuel. Not saying this is the case with your Aeromotive regulator, but it's not worth the risk having it on the car.

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