'60 Fuel Injection flooding fuel bowl

[George W.]

This thread covers it:

The #1 post and posts #21--#29 contain the the pertinent information.

http://forums.corvetteforum.com/show...errerid=378351

Thanks,
George Wright

[George W.]

Re: '60 Fuel Injection flooding fuel bowl

HI George, I see you had a host of replies on CF and have called me and some of my pals that work on FI's.
I don't go on CF very much as I waste enough time on forums now but I do enjoy it.

Hi John,
Thanks for the response and thanks for the time you spent with me on the phone last weekend.

Forget you have a fuel injection. Pretend you have a carbuetor on your car instead. What in the world would cause the carburetor to continuosly flood.
One might think that two much fuel pressure would unseat the needle and seat. Dirt would also. Also a bad float-wore out float.
YOu told me on the phone you used teflon tape on your fittings. Old JD here pitched the roll of teflon many years ago.
Getting back to your fuel injection that has an original 59 to 61 fuel filter. Many fuel meter covers (lids) have been cracked and butchered overe the years because of teflon tape on the inlet fitting. Teflon has a way of getting washed into the FI unit and really does damage. In fact you could even loose your engine over teflon as "seats"; would clog up and not work and then bent connecting rods.

Teflon is gone; have Loctite 545 on all fittings; thanks to your tip.

Fuel pump pressure. Gail Parsons told me in the old days that I was telling people bad information on FI engine fuel pump pressure. Gail always got right to the point. He said JD don't tell people 4 to 5 inches as that's too much. Gail said 3-1/2 to a maximum of 4-1/2.
Your cheapest test at this point is to go by a fuel regulator at an auto store and put it in the line between the FI and fuel pump. Then set it to 4" or less in your case.
That way you can eliminate the engine fuel pump.

Have not performed this test as I did not want to "hack" into the fuel line, and because the engine/unit ran perfectly for the 20 minutes during the cam/lifter break-in period---I would think that if excess fuel pump pressure were the culprit, it would have "shown" itself during this time? I'm not saying that I will not try to assess the fuel pressure and adjust according to your recommendation, but rather, I'm going to eliminate other other possible culprits first (further discussion on these things found below).

You called my pal Jerry and you called me. Not bragging but between the two of us we have been around the horn more than we really want to admit.
I am always here for follow Corvette/Chevy owners and even a few Pontiac FI owners.

Yes, I did have the pleasure to speak with you and Jerry. Both of you were generous with your time and knowledge. Thank you.

After you play with the fuel pump pressure call me back.

I never set a float a 2-11/32 though. The manual says 2-9/32 for float level. Then 2-27/32 for float drop. Gail told me one day to try 2-25/32 and see if I like it.
When my friend cut loose with a tip I listened and wrote it down.

Okay, next installation will be as you advise.

Does you float wobble around? No.

When you put the float pin in the float is it good fit? Yes.

Or are the float pin holes elonged as they typically are. If so that's a no-no--Float pin holes are snug.

Now let us discuss your fuel meter cover. When you put the float pin in the cover is it a snug fit. Or does it wobble around? If any of those issues are present then expect problems. Nice snug fit.

Is your float hanging up on the side of the fuel bowl. No, checked for signs of rubbing. Visual inspection of alignment when fitting cover to bowl looks great.

Not much else I can think of. Maybe the anti-siphon valve in the fuel bowl. But if it popped out the car would not run. Thought it might have popped out, but after "flushing the unit several times with fresh gasoline and B12 carb cleaner, the ball re-appeared". The ball now moves freely in it's chamber.

If it's not sealing then gas would shoot up and bounce off the top of the fuel meter cover. But I don't think any of those two items would be your problem.
Shake the float and see if it has gas in it. No gas in float--in fact, I submerged it (weighted down) to double check this.

What my flushing procedures have revealed is the presence of very fine, gritty, light colored debris. I believe this debris to be glass beads that were not thoroughly removed from the unit after cleaning. I am not positive of this, but after several "flushing s, I am seeing much less of this debris.
I have collected a sample of this "grit" and am investigating/asking if it's possible to have this tested and by whom.

Photo below shows debris after is settled in bottom of nice clean can:



Another photo of material on my finger and cling to the walls of the fuel bowl:




John

--

Thanks again for your response and offer to help.
In my next post I'll include the videos of the unit/engine running upon initial start-up.

[George W.]

Re: '60 Fuel Injection flooding fuel bowl

Engine running (for 20 minutes)
click on photos below for short videos.
Thanks,
G

[Clem Z.]

Re: '60 Fuel Injection flooding fuel bowl

a lot of leak thru i find in carbs is the gasket between the needle seat and the body because the center hole is to large. if the gasket does not have to be "screwed" over the needle seat threads it will leak.

[George W.]

Re: '60 Fuel Injection flooding fuel bowl

Hi Clem,
Thanks for responding

I did find this gasket to be in need of replacement

g

[George W.]

Re: '60 Fuel Injection flooding fuel bowl

Problem persists.

Actions taken to date:

1) Flushed and re-flushed all components (6-8 times) --seem to have eliminated all of the "grit"---weather it was left over glass beads or???

2) Installed thumb tack spill valve, even though the "goodguy" seemed to be working fine after the "grit" was flushed out and the cylinder and plunger honed with 1,500 paper.

3) inspected/replaced/checked operation of needle and seat several times----does not leak.

4) internal anti-siphon valve working properly

5) Replaced fuel meter bowl lid (thinking there was a leak that I could not detect)---no avail

6) replaced fuel filters (had added an extra at tank for insurance)---tested fuel from supply several times---clean--clean--clean.

7) reduced supply fuel pressure to 4 psi---same bowl flooding.

8) Float is in good condition (not leaking), alignment is perfect (not rubbing or "catching" on the bowl), fits snugly to the lid (no wobble or excessive play on shaft or float attaching holes), and is properly adjusted.

9) All fuel line connections "sealed" with Loctite 545

10) Every time this unit floods and I remove the lid, the first thing I check is the needle and seat, and every time it is sealing.

I know this makes no sense (as John D. and others have stated, if the needle/seat and float are working properly, and if there is no leak in the lid, then there is no other way for fuel to overfill the bowl), yet, it is happening.

Perplexed,
George Wright
210 748 4693
geopar@gvtc.com

[Clem Z.]

Re: '60 Fuel Injection flooding fuel bowl

does it flood while driving or when the engine is off ?? the way we fixed flooding on the dual 4 barrel corvettes when the engine was off was to drill a .015 hole in the valve plate of the fuel pump so the pressure side of the pump bled back into suction side when the engine was off

[George W.]

Re: '60 Fuel Injection flooding fuel bowl

Hi Clem,
Thanks for responding.

The unit floods while running, and sometimes while cranking.
Unit does not flood with the engne off.

G

[John D.]

Re: '60 Fuel Injection flooding fuel bowl

George, You say grit has been an issue. Is it black grit? Sounds like you have a so called reproduction 59 to 61 fuel filter assembly. That part alone could be causing the bulk of your problem.
Replace the filter with a 62 FI set up.(My favorite) AC GF-90 and a 62 fuel line. There is a chance your problem could go away. Or try a typical glass bowl filter that the carbs used.
Here's why I say this. The repro filter is not really a repro part but a reworked Holley filter that had two round tubes. The fellow who converted them for Corvettes did a wonderful job of removing those tubes and soldered on his hex fittings. But to do this he had to remove the inner lining. Then came the problem is he had to epoxy the inner lining back in.
Problem that you may have is the epoxy breaks up in tiny gritty pieces and clogs up the needle and seat every time you run the car.
If your filter is a known original then disregard the above.
One time I restored a 59 FI unit. THe owner took it to a regional and it flunked Ops. I was called to the judging field by the owner and sure enough his FI unit was running like a POC. So after he put the car on the trailer I took the FI unit home and found the filter had a lot of grit in it. We blamed it on the gas tank. So the owner put a new gas tank on this 59 and other parts leading up to the FI. Meanwhile I did the unit over. Free of course. So he put everything back to gether and the engine ran about 15 minutes and that was all she wrote. The owner was not a happy camper and of course it was my fault. So he brought the unit to my house on a Saturday and I had him sit with me at the work bench while I took the thing apart. Sure enough it was full of grit and we were floored and disappointed.
I found it that night it was the reworked filter. So I cleaned the Fi unit up again and he got rid of the filter assembly and put on a known original and the car ran like a clock.
I did not think of this issue until tonight. My story is 10-15 years old.
How can you tell if you have a repro filter? Take the gasket off the upper housing and look between the inner lining and outer lining. The epoxy breaks off into little pieces that look like chips of coal or something like that.
Take the filter off. Get a white towel and blow thru it with hi-pressure air. Betcha find grit. If you do then pitch the filter assembly. John

[George W.]

Re: '60 Fuel Injection flooding fuel bowl

Hope everyone enjoyed Thanksgiving with family and friends.

Update:

John DeGregory, You are "the man"---below is a video of the FI unit running again after getting rid of the fuel filter canister. I could not see any evidence of the filter assembly being epoxied, and the "grit" in this system was very light colored (thinking it was left over glass beads from the cleaning procedure), but none the less, after removing the canister the bowl flooding problem is gone.

Click on photo below for the video.



I regret not taking photos of the "test" procedure, but what I did was run a hose from the fuel line supply to the fuel meter lid (lid was upside down so that the needle was in the closed position), cranked engine and observed weather needle/seat and/or lid leaked. No leaks. Then opened the "valve" (fuel everywhere), then slowly closed "valve" and fuel supply stopped. Then installed an inline pressure gauge and hooked up fuel supply from an electric pump. Ran pressure from 3 to 8 psi and no leak. Then checked psi from engine fuel pump---6.5 psi. Since needle and seat performed well at 8 psi, I decided that fuel pump pressure was not the culprit. No fuel filter assembly, no leak.

Getting unit to perform was another matter.
Ran a fuel delivery test---drill to turn hi pressure pump while supplying vacuum to the diaphragm".



Found 4 "plugged" nozzles and found debris in the electric shut off solenoid (allowing fuel through system when solenoid closed.
pulled everything apart. Flushed, cleaned, flushed again, etc., etc.








Reassembled and ran another "drill" test----Perfect.

Did find a couple of things when disassembling the nozzles--- 3 0f the disks were "dull" side down---Don't know how important that is, but the manual states that shinny side towards the engine is correct.
Below is a photo of "shinny" vrs "dull" disks.



Found this diaphragm clearance to be well less than the .040 as recommended.



I adjusted to just over the .040 (required one full turn of the rod--made it longer), then adjusted the stop screw slightly--oh, found that both lock nuts were loose. Don't know if I messed up here, but tried to follow the Manuel specks.

For those of you who haven't had nozzles apart, here is a photo of how small the screens are.



Waiting on the '62 fuel line and filter to arrive.

Oh, I don't like this vacuum line routing. It rubs against the fuel line and pushes it onto the valve cover. I'm going to re- route when I can.



Here is a photo of another unit showing the vacuum line "behind" the fuel meter, and consequently positioned 'higher and away from the fuel line.



Finger's crossed, but I think we have solved the initial problems. I say "we" because so many members have been helpful.

Still need to perform "tuning" procedures, and I may need some more "help", but for now, things are looking good.

A hearty thank you, thank you to all who have spent time with me here on the site and with phone conversations.

George Wright

[Clem Z.]

Re: '60 Fuel Injection flooding fuel bowl

you should never use teflon tape on any fuel lines as it can break off and go thru the system. also you can over tighten the fitting and crack the housing because the teflon tape cut down on the fricton.

[John D.]

Re: '60 Fuel Injection flooding fuel bowl

George, I see you have an extra vent tube on top of your fuel meter bracket. In 1959 or so RP came out with a very crude looking anti-siphon valve assembly for retrofit on earlier models. The kit came with a top fuel meter bracket like on your 60. The siphon breaker kit went between the hi-pressure pump and the fuel bowl. Then a rubber hose went from it to the top of the fuel meter bracket. I don't know if your extra vent hurts anything or not but to be original you need another bracket or at least have that hold welded up and replated.
By the way George. You said you have a 60 fuel injection. Well your fuel bowl is not from a '60.
Appears you have a 58-59 fuel bowl as I see it stamped 902. A 60 fuel bowl would be stamped 252.
That's why you have the altered fuel meter bracket. John

[George W.]

Re: '60 Fuel Injection flooding fuel bowl

John,
The last photo above is of a '59 unit---I displayed this to show the vacuum tube routing as it pertains to the fuel supply line clearance issue ("pushing" fuel supply line against valve cover which will result in un-wanted additional heating of fuel supply.

Photo above that one is of the '60 I'm working on. It is a 252.

Still looking for information concerning the "grit" I flushed from this unit---How can I determine if is is glass bead material?

Any comments on my adjusting the diaphragm to .040" clearance?

Any comments on the shinny vrs dull side down installation of the nozzle disks?

Thanks again,
George

[Jerry G.]

Re: '60 Fuel Injection flooding fuel bowl

The shinny vs dull question . The disk is an orifice and as such has a knife edge at the OD of the hole on one side and a chamfer on the other. Putting them in backwards would affect the atomization of the fuel stream. Jerry

[George W.]

Re: '60 Fuel Injection flooding fuel bowl

Thanks Jerry,
I presumed there was a reason for the "direction" these disks were to be installed. Your description is excellent.
Glad I found the three that were in upside down and corrected.

Couple of other questions I have that are not addressed in the manuals I own:

1) torque specifications for--- a) nozzle assembly, b) nozzle block retainers, c) diaphragm self locking screws, d) diaphragm lid screws, e) fuel bowl lid screws, and f) hi pressure pump mounting screws.

2) How does an axle link go bad? If it's not broken, bent or otherwise damaged, what goes wrong?

One additional thing I found; bad terminal connection from my ballast resistor to coil.



The wire lead was not properly inserted into the connector, leading to a "sometimes" operation. This faulty connection resulted in flooding the engine cylinders with gasoline during a couple of start up attempts. I suppose I am lucky that major damage was not done. Glad I found the problem and corrected.

Some things I've learned since this "ordeal" began;

1) use of loctite 545 on threaded fuel line connections. And, to never use Teflon tape/paste.
2) Fuel filter canisters can be a problem
3) how to test fuel flow with drill operating hi pressure pump while applying vacuum to diaphram
4) glass bead cleaning can be a major problem if not properly flushed after use---Jerry Bramlet advised having the spill valve chamber "sealed off" during the cleaning process.
5) Why shiny side down is correct for the nozzle disks
6) Learned about the internal anti siphon valve operation, and how to replace or "plug" in off.
7) Learned how/why the spill valve operates, and how to prepare for proper operation.
8) learned that one should replace the "good guy" spill valve with the "thumb tack" style
9) Learned about the proper fitment of the needle/seat assembly gasket
10) learned that NOS gaskets that are old can "shrink"
11) Understand how orientation of main control signal line relates to engine heat from valve cover transferred to fuel supply line
12) Learned to double check all electrical connections.

13) The most important thing I learned is that there are many great people willing to share their time and knowledge. There is no way I could have gotten this far without the the help of fellow Corvette "Nuts".

Thanks to all,
George Wright