Falcon won't run

[Falcon62]

I finally finished the fuel tank hookup and decided to fire up the Falcon yesterday for the first time in months. Prior to fueling up, I noticed the fuel gauge was reading half on a new, empty tank, so I started checking. Have a good ground on the tank, good continuity to the sending unit, gauge unit checks out, constant voltage regulator is feeding 12vdc to temp and fuel gauge. Aha! 8)

I swapped the CVR for a known good one, tested it to make sure, and put everything back together. Fuel gauge now reads empty - good. Off to the gas station and bring home 10 gallons which brings the gauge to about half. Voila!

I cranked her over in 5 - 7 second bursts to get fuel up to the carb, and then attempt to start. While priming the system, I notice my tach needle is bouncing when I release the key in the "run" position. Hmm, looks like the same frequency as the CVR. I press on thinking I may have to find out why it's affecting my tach.

Once I get fuel to the carb, I try to actually start the engine. It sputters a bit, then I finally get it to start only to have it die. Over and over and over again. This is really weird, it's acting like it's running out of gas. I check the carb and it is very wet, I pull the throttle, and get a strong jet of fuel from the accelerator pump. Hmm, maybe the needle is stuck (newly rebuilt Holley 1v), so I pull the bowl off to find there was definitely plenty of fuel and I can see the needle is not stuck. I play with the float a bit to satisfy myself that it isn't sticking, and it never fails to drop as it should. Hrmm.

While under the hood, I noticed a ticking sound, like a relay, coming from the distributor when the ignition was in "run" position. Sounds like the same frequency as the CVR. Damn.

I pull the instrument panel back out (what a PITA) and unplug the CVR. Tach needle stops bouncing and no ticking sound from the distributor. Ok, now it should run - not. Does the same thing, will fire for a few seconds, and then die. Only now I know it's not fuel, but ignition related. It acts like the key is being shut off.

I messed around with it for awhile and then gave up in disgust. I'm tempted to reinstall the old CVR and see if that makes a difference, it shouldn't but it's the only thing I changed since the last time I ran it. I suppose something may have "died" while it sat, but really doubt it.

I'll have to test the DII today, check coil voltage, grounds, and ??? Any ideas would be appreciated. I just know it's gonna be something simple. :roll:

 

[PLP6400]

I have had this problem a couple of times. The first time it was the Tach shorting out. The second time it was the pink resistor wire went bad. I would try hot wiring the car. Jumper wire from the battery to the coil and if it runs with the key off, it is one of the above or maybe the ignition switch. As for your guage voltage regulator, check this site out. My son found this and did the conversion to his 65 Ranchero. I have since done it to my 65 Comet and it works great. No more faulty reading guages.
Hope this helps.

http://www.turbotbird.com/techinfo/ivr/Default.htm

 

[Falcon62]

Great link! 8) I've thought of doing something similar in the past, but never needed to until now. Since I was playing around behind the instrument panel, I won't be surprised to find I managed to pull a wire loose, short one out, or something similar. I'll know later this afternoon.

 

[Falcon62]

Problem solved, temporarily anyway. Apparently, I managed to get some part of the ignition wiring tied into the CVR circuit. The engine would fire and die as long as the CVR was connected. So, I disconnected it. Same problem. Had 12vdc at the B+ terminal on the coil with ignition on. Jumped from battery to B+ terminal on coil - no change. Swapped ignition modules, no change. Grrrrrrrr!

In a fit of frustration, I put the old CVR back in. Fired right up. I think I may have part of the module wiring involved with the CVR as coil B+ stayed constant. The wiring was a major mess when I got the car, and I don't have an exact wiring diagram for the options this car has, so I must have gotten something just a wee bit out o'whack.

At least I know where to start digging. :roll:

 

[Anonymous]

Falcon;
Check this: some dashboard CVR units from the '60s were the case ground for the dashboard. This scenario certainly sounds close to the troubles you describe, as this style of CVR was discontinued after the famous 'exploding Pinto' lawsuits of the 1970s. Today you can only buy self-grounding types, with +12v in one side and instruments out of the other: the enclosure is the ground on all new ones. If you accidently reverse the +12v and output sides, the whole 12v dashboard supply will click on-off with the CVR, causing some pretty interesting things, like ignition that runs while the engine is not! This scenario can also make the gauges read too high...

If your wiring is a mess...
try to ground your dashboard by using the ground connector from the original CVR. Then wire the ignition more directly from a source closer to the fuseblock. Make sure, also, that the grounding wire from the block-to-firewall is in good shape, especially after sitting unused for awhile. They corrode very subtly when not in use.

Hope some part of this helps.