FI HELP - J. Bramlett/J. DeGregory

[Jack U.]

Working on a 1963 fuel injection system. The problem is the car will idle
fine when sitting in the garage, but when you take it out and drive it and
push in the clutch to come to a stop sign, it will die. Then it will start
up immediately and run fine. Other than this, car runs perfect, no
driveability issues. Any ideas would be greatly appreciated.

Thank you.

[G B.]

Re: FI HELP - J. Bramlett/J. DeGregory

Engine death upon return to idle while on the road is usually caused by one (or a combination) of these three things:

1. Faulty spider. Don't get me started on reproduction spiders. You can read my comments under "Tech Tips" at www.jerrybramlett.net.

2. Poor breathing through the forward balance tube. This could be caused by partial blockage, or by engine fan wash if one end of the tube is disconnected.

3. Improper fuel meter calibration and / or idle mixture settings. The last time the unit was properly calibrated was... ?

[George J.]

Re: FI HELP - J. Bramlett/J. DeGregory

Jack,

also verify with an electronic meter what your idle speed is. The tach could be off by a few hundred rpm and this could be a contributing factor.

George 31887

[Jack U.]

Re: FI HELP - J. Bramlett/J. DeGregory

I do thank you (again).

We (my mechanic an I) were stumped after going through the system again.
We assumed we missed something. We believe it was something obvious.

We'll be in personal contact if we can't figure it out as it was running
perfectly recently.

Your website is a valuable troubleshooting resource.

[John D.]

Re: FI HELP - J. Bramlett/J. DeGregory

Jack, Here's a short list of things for your to consider besides what Jerry said. Vacuum signal problem. Remove the air meter and clean the small passage way leading to the idle fuel screw circuit.Use a long thin drill bit by hand and clean out the carbon. Carb cleaner alone will not do this. While on the air meter, make sure you have the proper seal on the end of the vac. line that screws into back side of the air meter. This is the main signal line and extremely important. I use a small o'ring-same one that is used on the spider supply lines as I never liked the original style. Since calibation is questionable don't worry about it for a bit and just go over to the fuel meter side and turn in the economy stop about 1/2 turn with an allen wrench. Means turn the allen set screw clockwise-to the right-toward the firewall-all of the above to increase the mechanical advantage of the accelerator pump called spill valve. This will give you more gas at the lower RPM. Speaking of RPM bump it up to about 900 or more as you may have a fuel pressure problem caused by the hi-pressure pump and or spider. Make sure you spider check valve is clean and not sticking. If it has been resoldered or repaired it's history. If your hi-pressure pump does not have the proper clearances or has not been lapped when rebuilding it is the culprit. CHeck the float settings also. Cheat a little on the float and don't use the factory recommende float drop of 2-27/32".GO a tad higher. In the fuel meter bowl if you have an inferior axle link that's out of balance that will cause your problem. Check to make sure the engine is putting out enough vacuum also. Make sure you have the correct vacuum advance. Squeaky tight rubber hoses, etc. Good luck, John.

[Matt Scheibe]

Re: FI HELP - J. Bramlett/J. DeGregory

Jack- I had the same identical problem immediately after an overhaul of my fi unit. The motor would die as soon as I slowed to a stop. My mechanic found the problem to be a faulty signal boost valve. But I don't know how he determined it was the source of the problem. My car's a '64.

[Michael H.]

Re: FI HELP - J. Bramlett/J. DeGregory

Jack,

Just curious, while test driving and you have this problem, is the air cleaner installed on the car? No air cleaner, and especially no air cleaner adapter, can definitely cause the exact problem you describe.

[John D.]

Re: FI HELP - J. Bramlett/J. DeGregory

Michael, I remember in the olden days we used to disconnect the AC and drive threw the car hop joints just so the guys could hear the whistle noise and the clutter of the solilds.. Those units do not like to be run without an AC though. Even in the old race car they ran an air cleaner with a home made AC adapter with some ugly plumbers fitting soldered to it to hook up the balance tube. THe NOS chrome balance tubes you have seen for sale the last 40 years aren't worth a crap. I have a theory that RP scrapped 1000's of them as rejects as they are not bent properly at the fuel meter side where they "plug" in. I have had to have a ton of them reshaped over the years and then rechromed. Cost a fortune. Still see them for sale and guys paying big bucks. Just shake my head. A poor fitting balance tube on Jack's fuel meter if this is the case is not good either. The solid axle units seem to behave more radical from this problem though than the mid years. Wish someone made a good repro for a 63 that fit like a glove. The current repro will not fit at all as it hits the cranking signal valve. Running with no AC is a no no for sure. Messes up the signal just as you said. Notice I am not a repeater of info and taking credit after you gave the answer. I have to practice up on this art though. That's why they call me Art for a nickname. Jr.
By the way Mikey I hear the swamp is freezing today. RJ told me. My GMC has frost on glass. brrrr. RJ said his pigeons are freezing. Heard he was gonna send Jerry some pigeons for future shipments. Told me so. Not my idea. Jr.

[Jack U.]

Re: FI HELP - J. Bramlett/J. DeGregory

Oh Yes.

The air cleaner is there and it is original.