books

iTrader: (8)

I had replaced my 850s with 1300s and have discovered fuel leaking. I have not been able to isolate the problem. So, I have decided to replace the FPD and fuel lines. I have already removed the rats’ nest and would like to know if I should just go ahead and pull both rails and connect the fuel lines? Or should I try and replace the lines while the rails are attached to the motor? If I pull the rails, with the injectors still on the rail, what parts do I need to replace…. insulators, air bleed socket, any o-rings?


thanks

zUMIEz

iTrader: (2)

Before you do all that, why don't you pressurize your fuel system with your engine off and see where your leak is. To pressurize the fuel system, you need to activate the fuel pump by grounding the fuel pump node in the "Diagnosis" port on the driver's side fender wall. Rather than try to explain which one is the fuel pump node, it would be easier to find it in Part F of your shop manual. It is discussed/shown in several places. All you need is a short piece of wire (think paper clip) to ground the node.

If you dare doing it by description, standing at the front of the car looking down on the "Diagnosis" grid, we are concerned with the row of holes to the left hand side of the grid. Loop a wire from the hole 2nd from the back (fuel pump node) to the hole 4th from the back (ground). Turn the ignition to the "ON" position (do not start the engine). If the fan comes on your exactly backwards. You will hear a whirring sound when the pump comes on.

Once you have the system pressurized you will then be able to see where you are leaking fuel. Then what needs to be done becomes a much easier question to answer. Be brave! It is not that hard. This is also a good way to test your system once you have completed your repair.

books

iTrader: (8)

thanks for your reply....I have already connected the F/P and Gnd in the diagnosis connector grid (at least once while the UIM and rats' nest were in place and subsequently when they were removed))....unfortunately. I have not seen where the fuel was leaking I performed that test with both the UIM on and removed...I have also applied physical pressure to the line themselves and still do not see where the leak is originating... I know it is leaking from somewhere because I have seen the gas dripping on the ground (I have another thread discussing this)...as you are probably aware it is extremely difficult to see leaks with the UIM and rats' nest in place...hence that is why they are now removed...

again thanks again for your reply

zUMIEz

iTrader: (2)

[QUOTE]Originally posted by books
[unfortunately. I have not seen where the fuel was leaking I performed that test with both the UIM on and removed...

Then your leak may be due to the insulators under the primary injectors being pinched or not properly seated in the ports. Pull up the primary fuel distributor (without removing the injectors) and see if the insulators are in correctly.

books

iTrader: (8)

That sounds reasonable. I can do that, I just need to know if I remove either or both rails what part I have to replace. I do have 2 new insulators that were for the 2ndary rail, hopefully they are the same as the primary. The primaries have never been removed. Other than checking for pinching, what should I look for? If I pull the rail, what are the parts that ideally should be replaced...since I'm there..insulators??...air bleed socket or any o-rings???
I would prefer to have all the parts on hand and complete the effort properly.

thanks again for the response, it is appreciated

zUMIEz

iTrader: (2)

The insulators for the primary rail are different than for the secondary rail. The secondary insulators are gray and are accordian like. The primary insulators are black bands. You are looking too see if they are mashed down in the holes or are pinched and flattened from riding the rim. They can also become torn from either scenario. You should not need to replace anything other than the insulators.

books

iTrader: (8)

thanks so much...I'll probably just order the insulators and pull the rail when I receive them...I intend to replace all the fuel lines and the o-rings (at the ends of the rails not the injectors), FPD,FPR and insulators. So, I'll end up pulling the rails to replace that stuff, shouldn't have any leaks then..I really do appreciate your time in answering my questions...

zUMIEz

iTrader: (2)

Just wondering! Did you fire-up the engine after you installed the larger injectors? The fuel dripping may just be what free flowed into the engine while you were changing out the injectors. It will actually seep out the exhaust ports if it free flows into the engine.

books

iTrader: (8)

I pulled the 850s a few months ago and while they were out, i.e. no injectors in the rail, I noticed fuel pooling underneath the car, approximately behind/below the turbos...the car has sat since then...waitng on parts...bought some 1300s installed them (forgot all about the leak) and tried to start the car...did not start, after a few brief attempts...got out of the car and smelled gas...looked underneath and it was puddling again in that same area...so I assume I had a leak....so....what do you think?

zUMIEz

iTrader: (2)

The first part of your description is what I am referring to. But it doesn't seem likely that raw fuel would stay harbored in the engine for several weeks. Had you installed the 1300s just before you tried to restart the engine? Meaning within a couple of hours? Just supposing now that raw fuel was harbored, you would actually need to fire-up the engine to clear out the excess fuel. You basically have a flooded engine situation until then. However, if it sat a long time between the time you installed the 1300s (the point when your system was truly closed) and the time you noticed the leakage or it has continued since then, then something else is wrong. Over time the accumulated fuel would evaporate.

books

iTrader: (8)

I'll try to recall the best that I can. I believe I installed the injectors the day before I attempted to start the car.

Back a few months ago when I pulled the 850s out, it was leaking for a couple of days. I think I removed the gas cap and that eventually stopped the dripping. I hadn't seem it leaking until I tried to start the car recently.

I didn't smell any fuel until after I attempted to start the car with the 1300s in it and that was when I discovered fuel dripping again.

When the fuel "free flows" what path is it taking?

I am trying to be careful, and have already pulled it apart...didn't want an engine fire...but would like to understand what has happened

zUMIEz

iTrader: (2)

When there is pressure in the fuel lines and you remove the injectors, fuel will free flow into the engine until the injector (imagine a drain plug) is reinstalled. The fuel is dumping directly into the combustion chamber. What you are seeing on the garage floor is what is dripping out the exhaust ports (and the exhaust manifold and whatever opening it is finding to get to your garage floor). If that is all you have going on, start it like you have a flooded engine, let it run for several minutes to clear itself out, try to move away from the area where fuel has been dripping and then see if you still smell raw fuel. Hopefully you can do this before the exhaust manifold, etc., get too hot.

books

iTrader: (8)

So your thinking that it was probably passing fuel from when the injectors were not in the rail. I think I'll put it back together and turn over the motor a few times without spark and fuel. Then, perform the flooded motor procedure.

I only wish you would have seen my thread before I pulled all of this stuff off.

I'll post the results here so others can benefit from your knowledge.

I assume most people just pull out the 850s and immediately install the 1300s...not wait weeks. In my case I was waiting for the injectors an UIM and my throttle body. I was originally going to have the 850s cleaned and placed in the primary spot.

zUMIEz

iTrader: (2)

If you think you have everything else tight, i.e., injectors with seals installed correctly, hoses clamped, rails mounted square, etc., it is possible. Seems like an awful long time for fuel to be in a "free" state.

books

iTrader: (8)

now, you have me second guessing....perhaps this is pertinent....when the 850s were first pulled there was nothing in the rail for a day or so maybe more... I didn't notice the fuel dripping at first (after I pulled the 850s)...I started to smell gas, I'm guessing a day to a few days later.... then I noticed fuel on the floor...sometime later I removed the gas cap and pushed the 850s back in the rail that is when it eventually stopped dripping...perhaps the combustion chamber was full of fuel and may have not evaporated completely when I attempted to start the car....I just don't see any leaks and your explanation sounds reasonable

zUMIEz

iTrader: (2)

I think you should try to purge as much gas as you can (dry start with no spark) and then start her up.