F.I. engine quits running 5 seconds after key returns to ON position

[Richard S.]

was driving when this first happened. thought it was ignition wire that runs to ballast and coil, but its not. tested by removing wire from igntion switch and car starts but shuts off immediately. my problem is that car continuues to run for about 5 sec after ignition switch returns to ON position then shuts off as if out of fuel.the engine fuel pump is good and the filter clear. i removed the high pressure pump cable from dist. and the problem was exactly the same. the fuel bowl is full of gas. it seems like when the initial start up solenoid turns off when the key goes to the on position there is no gas being pumped thru the spiders. but how do i check this?

[Don H.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

Does it have an anti syphon valve?

[Dan H.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

Check the ballast resistor, replace it or check continuity accross the terminals with all leads disconnected.
Dan

[Jeff A.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

Junction block on firewall? check for 12V at the coil?

[Richard S.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

yes it has anti siphon valve and ballast has continuity and 12v to coil

[Jim L.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

Richard,

I'm sorry to read you are having a problem. Is this the 7380 unit on your '64 that's giving you trouble?

Assuming so:

You said you removed the pump drive cable from the distributor. Go ahead and pull the cable out of the pump and verify that it hasn't broken.

If the cable is intact, then the unit has an internal problem. My best guess is that the internal anti-siphon check valve I installed has popped out of its cavity. In any event, some partial teardown is going to be needed to do any further troubeshooting.

One way or another, I'll help you resolve this and get you back on the road. Is your email address still the same (yahoo)? If so I'll contact you so you can get current email and contact info for me.

Jim

[George J.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

If you removed the cable from the distributor the car is not supposed to run at all. To check a fuel feed problem, pull one of the spider lines (put a plastic bag or small vial over it) and see if fuel is being sent when cranking with the solenoid disconnected.

George

[Kenneth S.]

Re: F.I. engine quits running 5 seconds after key returns to ON position


Ken

[Jim L.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

If you removed the cable from the distributor the car is not supposed to run at all. To check a fuel feed problem, pull one of the spider lines (put a plastic bag or small vial over it) and see if fuel is being sent when cranking with the solenoid disconnected.

George

Not always true.

FI units equipped with starting fuel bypass mechanisms (all '57 and '64, '65) will supply enough fuel during cranking that the engine will run for a few seconds after releasing the key. The innards of the unit can be completely inoperative and it won't matter; the engine will run briefly.

If Richard's engine runs for as long as 5 seconds after releasing the key, he does not have an ignition problem.

Jim

[Richard S.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

hello jim thanks for reply. cable is good car seems to just run on fuel from bypass mechanism.will contact you today by e-mail or phone

[Rich P.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

I would not rule out a faulty ignition switch.

[Matt L.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

was driving when this first happened. thought it was ignition wire that runs to ballast and coil, but its not. tested by removing wire from igntion switch and car starts but shuts off immediately. my problem is that car continuues to run for about 5 sec after ignition switch returns to ON position then shuts off as if out of fuel.the engine fuel pump is good and the filter clear. i removed the high pressure pump cable from dist. and the problem was exactly the same. the fuel bowl is full of gas. it seems like when the initial start up solenoid turns off when the key goes to the on position there is no gas being pumped thru the spiders. but how do i check this?

is this a cold run problem or hot run problem ? my 64 would do the same do to vapor lock on warm days with engine warm. i have the 375R unit. we replaced the spill plunger with a "good boy"i'm not sure of the name. but it would flow more fuel. that helped and of coarse running 100LL helped even more. i'm not an expert but that's what worked for me. until i had the problem fixed i manually reset the choke and that would help fire the engine and keep it running until cooler fuel arrived to the spider.

take care,
matt

[George J.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

Not always true.

FI units equipped with starting fuel bypass mechanisms (all '57 and '64, '65) will supply enough fuel during cranking that the engine will run for a few seconds after releasing the key. The innards of the unit can be completely inoperative and it won't matter; the engine will run briefly.

If Richard's engine runs for as long as 5 seconds after releasing the key, he does not have an ignition problem.

Jim

Jim,
thank you, I didn't know that. I would still pull one spider and a spark lead, and check them while the engine dies. I would think you could tell if the engine stops because the fuel is stopping, or the spark is stopping. It has to be one of them, and if it is the fuel, wouldn't it take a few cranks to get the fuel flowing again on a restart whereas the spark would be instant?

George

[Jim L.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

Expanding on what I wrote earlier.....

FI units which initiate starting fuel flow by way of a cranking signal valve have no source of nozzle fuel pressure other than the internal gear pump. Break a pump cable and the engine shuts off immediately and will not re-fire, not even momentarily. Such units include 4900, 7200, 7250, 7320, 7360, 7375, and maybe a couple of other seldom seen models.

For FI units with a starting fuel bypass circuit, nozzle fuel pressure during cranking is provided by the engine mounted fuel pump. And, compared to normal idle fuel pressure, the cranking fuel pressure is very high. As a result a LOT of fuel flows during cranking and the engine can easily run for several seconds on just the residual cranking fuel. Units configured with starting fuel bypass mechanisms include 4360, 4520, 4800, 4960, 7300, 7380, and maybe a few other obscure models.

If there is an ignition problem..... say the ballast resistor has opened up.... even if the engine fires during cranking, it will immediately stop as soon as the key is released back to the "ON" position. There will be no delay. None. Zip. Zero.

In the case of Richard's FI unit, a 7380 model, it's providing starting fuel and the engine is getting ignition. What the engine is not getting is a sustained supply of fuel after engine cranking stops.

The symptom he has described is completely consistent with what happens when the internal anti-siphon check valve becomes dislodged from its cavity internal to the fuel meter. This isn't a common occurrence, but neither is it unheard of.

The picture below shows the anti-siphon check valve. It's the tiny brass thingy visible through the magnifying glass. (This particular check valve has failed, but it hasn't been dislodged from its cavity.)


Jim

[George J.]

Re: F.I. engine quits running 5 seconds after key returns to ON position

Jim,
thanks. I understand your point better.

George