Technical 58 T-Bird mysteriously dies when hot.

Alright, thank you all for the patience, the car is generally a weekend project so that's when I will have the most new info, we recently got a new oscilloscope for an unrelated project, and got some readings from the bird when it is hot, the yellow line is the example waveform provided for vehicle ignition provided by the company who makes the scope, while the cyan is the reading we got. Ocaissionally the waveform would wander left and right, even with the trigger and the timeframe remaining the same. The two attached photos are of the coil and cylinder 8 when hot, the coil is the one that matches the template wave form better, aka, the spark looks UGLY on cylinder 8, any new ideas?

 

@okiedokie
I went through the carb once, and then there was a different but related issue in relation to the car dying, it turns out the rebuild kit had a different size power valve than the original, so when we went back through that my dad checked to make sure I didn't accidentally miss something else. The fuel pump is mechanical, but that we replaced that about a month ago with a new one, the old pump definitely had issues. And although they are the same year, the bird in the profile picture belongs to Billy gibbons from ZZ top, which he appropriately named the "Mexican Blackbird". But since my dad just inherited my grandfather's 1922 Ford model T, which needs electrical work and a restoration after it sat 20 years. Thank you.

 

Thanks! I will try that in the future! But I personally think it is almost proven an ignition problem now, no longer fuel.

 

That's a nice selfie.

 

I used to have a car that acted exactly like this and the fuel line was getting too hot. I made a little heat shield for the fuel line. You say you checked and it is not vapor lock, but just saying -- it worked for me. You could try it with aluminum foil and see what happens.

 

I currently have the reflective heat tape on the bowl of the carb and on the fuel line all the way down to the fuel pump, I know that if it was vapor lock the bowl in the carb would not be filling, and I actually removed the top of the carb right after it died when it was hot and the bowl was still full, so I have narrowed it down to ignition being a large problem that needs to be addressed first, then I can go back and check again if it still isn't running right, but I want to be sure ignition isn't the problem first before I go back to messing with the fuel.

 

you are wasting a lot of effort here..Take the damn dist out and put a stock one back in it...Hardhead...L see that you are 17 yrs old so stop trying to dazzle all here with BS

 

Put a new coil to dizzy wire in it. Fixed mine !

 

Lol, now that's the plan, my dad just needed more definitive evidence before we replace the distributor and pertronix, he just couldn't be convinced the distributor was the problem, ha-ha

 

Situation update:
New distributor is in the car, but even with all my measurements the gears didn't mesh until I tried to start the car and now the timing is off. Tomorrow is fixing that issue and finding TDC for cylinder 1 and aligning the distributor to match. Attached are pics of the old distributor and the new, when you turned the shaft you could hear the bearings grinding against one another, and it wears a ford badge, and the diaphragm for the vacum advance was in VERY poor condition, which leads me to believe the distributor was original to either the engine or the car.

 

Hi MRC,

I used to work as a service manager for a fly by night distributor maker until they sold the company out from under us last year.
Any way, I would suspect a bad ignition module if you can hear a misfire and the tach starts to wander before every thing quits.
We had quite a few modules that would quit or get real flaky when hot. Coils can do the same.

Testing with known good parts is highly recommended.

We had one customer that insisted only genuine GM modules, that worked pretty good until management tried to cut costs on the rest of the distributor. Then the failure rate went through the roof. Even had a bunch of bad (loose) harness connectors causing trouble. (how many people inspect the little metal clips inside a snap together connector?)

Make sure that all of your electrical connections are good. Check for frayed wires especially on power and ground to coil.

Also good to verify cap and rotor are clean and bright not burnt. (more of a problem on Chevy/Honda then Ford)

Hall effect pickups will burn out with bad ground, reluctor pickups are tough, but can be hooked up with reversed polarity that can cause trouble.

Good luck with your trouble shooting.

Fuel sprayed down the carb while cranking will tell you if it's a vapor lock problem.

 

Alright, Good News! The car was running, albeit pretty shaky earlier, the timing is right on and doesn't wander, but it ran out of gas, and when it would lean out the mixture as it was dying it ran really really nicely, so tomorrow is more gas and mixture adjustment then a solid test drive to ensure it is all good now! Thank you for the input everyone!

 

Did you call them, and talk to them?

 

Check the gap on your magnetic pickup. If it is to wide your car will die. I have a Mallory magnetic distributor. When first installed it would die when hot and refuse to restart. I closed the gap and it cured the problem.

 

Thanks! Yeah, once I found out that was how you adjusted dwell to a point on that ignition I definitely messed with it, but on the scope it is showing good spark at all temperatures right now.

 

Ask some of Watson's followers. Or most mild custom fans on here. Or anybody else that is breathing.