Hi,

Been awhile since I posted on here but I have a question that hopefully someone can answer.

Before I begin I should start by saying that my car was running just fine with the stock lower intake and runners... fuel pressure was fine, driveability was fine ( I guess someone sensible would say, why would you deliberately screw up a perfectly working car? If you don't know the answer then you definitely won't understand this hobby

So here we go...

I just installed an Edelbrock hi-flo lower intake and large runners on my L98...

Everything went smooth, until I put my fuel rail back in... the rail seated down into the lower intake just fine (just like stock lower intake, with that sort of dull snap if that even makes sense)....everything bolted back up just fine. Then when I turned the key ahead to check the fuel pressure I noticed on my fuel gauge that the pressure quickly dropped off almost instantly. I suspected a bad injector as a couple of spark plugs were soaked in gas.

After looking at every possible angle I pulled the rail out and left it connected to the fuel lines so I could see the injectors as the fuel rail pressurized. I saw that two of my injectors were dripping and one more was "damp".. this is not normal, they all should be dry under a fuel pressure test. So I replaced them with a few spare stock injectors and did the pressure test again, this time I didn't have any wet injector tips and the fuel pressure stayed up on the gauge. So thinking I solved the problem I put the rail back in place and proceeded to put everything back together.

Went to fire her up and she ran bad.... stumbling, bucking, like I had plug not firing. Shut it down after a few minutes of trying to figure it out and noticed that the fuel pressure was falling off again. I confirmed that the fuel pressure was falling off by priming the pump, same thing happened, pressure comes up and then immediately falls off...Arggghhh....

So I tore it all down again and pulled the rail... this time the injectors didn't seem to leak... put it back down into place and primed the pump, first prime of the pump and it seemed fine, the pressure held, second time I primed the pump I noticed the fuel pressure dropping off.... weird or what?

So at that point I decided I am going to replace all of the injectors. The stock injectors were serviced about 5 years ago by Rich at Cruzin' Performance, but that was 5 years ago so who knows...

Questions....

1. Since the problem seemed to be worse when I installed the fuel rail and seated into the Edelbrock lower intake, could the intake have anything to do with it?? I don't think it can because to me it seems like the injectors just fit down into holes which are access ports to the heads. But I could be wrong!

2. A smelled a little bit of fuel in my oil.... this was probably due to the fact that the injector was bleeding fuel down into the head on a couple of cylinders... I ran the car for literally no more than a couple of minutes... other than obviously not running the car again until I get this fuel issue straightened out and changing the oil/filter, could I have done any damage?

3. I am going to replace the injectors with a set of Ford SVO 24# M-9593-AA302's (see the link below)... has anyone ran these injectors with the Edelbrock Hi-Flo lower intake? Any issues to know about? Fitment, etc etc..

4. The new injectors are the EV6 body style with the jetronix/minitimer connectors... these are the right connectors for my harness right?


http://www.fordracingparts.com/parts...tKeyField=9043

Any help would be appreciated here!! I need to get my car running again by July 1st at the latest as I have an appointment at our local Dyno Shop to get my car properly dyno-tuned by a professional tuner (he will be burning me a new PROM)....

TIA!

 

Further info from today....

I drained the oil just then and it came out looking a medium coffee/milk color.... it was full of fuel so I know that one or more of the injectors were pouring gas down onto the cylinder and that was bleeding past the rings and into the base pan....it almost made me cry to see the oil filter pour oil out like it was water...

I only ran the car for no more than a few minutes so I hope I haven't done any damage to the bearing/rings...

Do anyone have any pointers on what I should do to minimize the damage I may or may not have done due to so much fuel pouring down into the base pan??

I was thinking of filling her up with cheap oil and drain that out and then do another cheap oil change before I attempt to fire her up again.... then if/when I get her running right I will do a final good oil change...

 

I should add that I did lose some coolant down into the distributor hole when I was topping up the coolant .... I didn't see that there was an extra coolant hole in the back of the intake that needed to be blocked off and some coolant went down into the distributor hole.... wasn't much but maybe enough to turn the oil the light brown color.

 

1. I don't see how the intake, runners or properly working injectors could affect fuel pressure. (Since the distributor was removed to swap the manifold, double check timing is in phase, not "180 out" and initial advance is set properly. I installed SLP runners on the wrong sides and had a huge vacuum leak. It ran, but idled at 2000rpm.)

If you "key on" and get 40+lbs, but immediately lose pressure, I would suspect either the one way check valve in the fuel pump is bad (but the engine should still run) or the fuel hose connecting the fuel pump to the fuel line in the tank has broken. I noticed your specs include a 255 Walbro pump. I have the same. If your pump is internal, did you use the special fuel submersible fuel hose when you installed that pump? You need to use 30R10 spec hose. Regular FI hose (30R9?) will "melt" over a few weeks or months.

"SAE 30R10 Submersible Fuel Line Hose. This hose is specifically designed to be used in applications where the hose will be submersed in fuel. Other fuel hoses are only designed to have fuel inside them and when they are used for submersible applications, they will begin to degrade and swell, and in some cases, fail."


2. A little fuel in the oil shouldn't hurt anything.

3?

4?

 

Yeah I do have the Walbro 255 pump... but it has been installed for over 6 years now without a problem. I never had an issue with fuel pressure in all that time, it is an internal pump but I can't remember if I installed any special hose or not it's been 6 years and my memory isn't that great ....With the rail out of the lower intake the pressure comes up and stays up, no drop... it's only when I put the injectors down into the Edelbrock intake that I have the immediate pressure drop....so something weird is going on....

 

When you say you pulled the rail, do you mean you pulled it up and away from the manifold and flipped it over to view the injector tips or do you just barely lift the rail up to pull the injector tip just out of the manifold? If it's flipped over, maybe a line is pinched and you're getting a false pressure reading.

In any event, if your fuel pressure comes up to proper psi, then immediatley falls off, you've got to suspect the regulator, check valve, fuel filter, pump-to-line hose or the pump itself.

Did you try pinching the return line closed to see if the pressure remains high when the pump cuts off. If it does, then bad regulator. If it falls, bad connector hose, check valve or pump.

Some other ideas:

"Not Enough Pressure
Choppy idle, poor engine performance and misfire can all be caused by low fuel pressure. Low fuel pressure could mean a clogged fuel filter. Check and replace the fuel filter before going after the pump. Fuel tank crud can also clog in-tank sock or in-line filters. Test the fuel pressure regulator." Is there plenty of gas in the tank?

 

I pulled the fuel rail completely out of the intake and propped it up on a cardboard box so I could see all of the injectors... connected both fuel lines to it and primed the pump.

I don't think it's the pump or lines/filter, etc etc because all the while she was running like a bag of dirt (for about 1 minute or so) the fuel pressure never faltered, it stayed at 43 psi... so that tells me the pump is doing what it is supposed to do, supply fuel and keep the pressure up.

I really think it's one or more injectors that are just bleeding fuel down into the intake when they are not supposed to ... this would cause an extremely rich condition on one or two (or more who knows) cylinders... I would thinking that would give me the symptoms of almost cutting out, bucking, shaking, etc etc, it seems this would be the only way I could find fuel down into the oil..... but maybe I am way off...

 

This was the first thing we thought of actually because that would certainly cause the poor running for sure.... my buddy that was helping me is a certified GM mechanic and we checked and double checked the timing and it was right.

 

Those injectors worked like a charm.... I managed to fire up my car last night and she fired up perfectly.

What a nightmare install this Edelbrock lower intake/runners and injectors turned out to be , anything that could go wrong did go wrong for me... I must have had the runners/upper plenum and fuel rail off a million times, so many times that I managed to strip out one hole in the runner (the one that bolts from the back side) and one in the lower intake, had to retap those...

I am certain that I can be down to the lower intake in about 20 minutes now blindfolded

My car is running a little rich, that is for certain, but I expected that with these 24 lb injectors running at 43.5 psi... but she runs really smooth.

On July 4th I will be getting my car professionally dyno-tuned so hopefully that will sort out the fuel issues...

 

i feel your pain brother. i just did practically the same mod except i used the tpis big mouth manifold. its the same as the edelbrock 3860. i have to say though with the exception of the coolant popping out of that same hole as you mine went real smooth. that extra hole is there for the vette guys. my only issue now is the little clips that hold the injectors onto the rail cant go back on with my slp runners. there is no possible way to get the wiring harness on the injector and clear the runner.

 

I had clearance issues with my fuel rail and the runners... had to shave off a fair bit of material on the fuel rail so they never interferred with the runners. I didn't have any issues with the injector connectors though... two were slightly tight but I managed to get them on without too much of a fight, I had to turn the injector just slightly....

As for the stock injector clips... well they just won't work with the newer injectors. I fabbed up a set of clips out of a newer style GM injector clip, worked fine. Can't see how the clips would interfere with the runners though as they are on the inside of the rail??

 

actually the clips dont interfere with the rail. if i put the clips on they pull the injector up into the rail too far for me to clip the harness on the back driver side injector and the front passenger side injector. even if i turn them a bit which i had to do to get them in. they had been in with no clips since october and now back in for 2 weeks with no clips and im not having a problem so far. my buddy said im asking to burst into flames but i dont see any movement or leakage on them.

 

What kind of injectors are you running? My modified clips had the injectors sit just right in the rail/lower intake... no issues at all with clipping on the connectors...

 

they are bosch 24 lb injectors. its not the injector itself its the slp runner blocking it so i had to push the injector down some and turn it slightly