88 Ford 460 keeps dying

[That1skater]

I'm driving a 1988 Gulfstream Sun Vista, has a Ford 460 carburetor ran V8.
My issue is it will die a bit after running.
What I've done so far,
I've confirmed there is not In tank fuel pump only external

Has a brand new fuel pump, new vapor separator fuel filter, I've wrapped the fuel pump and filter with a heat guard and the fuel line with a Cool It racing thermal sleeve that both can take 400°F direct contact and 2000° radiant heat.
Has a fresh tune up,
Timing is good,
Carb has been freshly rebuilt and tuned
Temp runs between 160°f and 170°f
Running mid grade has

And yet it will running steady after warm up for a good period of time then when I go to push the gas it bogs out till I either stop or till it dies. I've confirmed there is gas getting into the carb, the accelerator pump is pumping and idk what else it could be.

Today is Aug 21st, I had it running yesterday perfectly, I was able to rev it really high, ran it for almost a hour on idle and didn't die at all.
Went to test drive today, started up fine, ran great after warm up, temp was good, and I put it in gear and it bogged out and back fired load like a gun shot.
I've talked to carb specialists and done everything they have said, I talked with other mechanics and done what they said.
Now I'm resorting to posting on here and see what you guys think.
I've lost a job because of this and now am missing my friends memorial because this thing likes to play jokes on me.
Thanks for your time;

[Gjac]

So you put a new coil in and it still bogs down, just check your wires at night and see if they are arcing to ground, it the wires are bad you will see arcing from the ign wires to ground, if you don't see any arcing I would look at fuel delivery. Try spraying carb cleaner in the carb while you are reving it up and if it revs up and does not bog down I would look at your fuel pump. I would think your vehicle came with a fuel pump in the tank. Someone may have installed an external fuel pump also. There is a certain flow rate for each engine that needs to be met so engine can run at WOT. Pressure may be fine but if the flow rate is not there the engine will bog down.

[time2roll]

Yes sounds like an ignition issue. Best to be back to OEM equipment. Encouraging to hear the improvement.

[That1skater]

Alright guys heres a update:
so there was quarter inch fuel line from the steel line to carb so i replaced that with the factory 3/8ths line, went though the rest of the rubber sections to search for any old lines that may needed to be replaced as well as any other that may have been to pliable.

I also found that the coil that was on the block had so weird oily substance all over, may have been from the inside of the coil because there isnt any signs of oil leaks around its vicinity. also note that someone had replaced the original coil connection and coil with a Accel super stock coil and its typical terminal connections.
so i replaced the connection and coil with its OEM parts(new),

i started it up and noticed it didnt take nearly as long to start on a cold start like it did previously so thats great lol, after a good while of running( i forgot to time it but will on the next go around) i noticed it went from running between 160F-170F to a cooler temp of 140F-145F.
Can a bad coil really mess with temperature like that?


Also no loud back firing this time while stepping on the gas; as well as it didnt die on me but after i rebuilt the carb i had it idling for almost a hour the day before my test drive which when i attempted to drive it bogged then died as soon as i put it in gear to drive away.


over all it does sound better and run better but i noticed it still has that faint bogging sound when i rev it, im not entirely sure if thats because of it being a big ol V8 or if it is still bogging. i havent test drove it yet due to the temperature of the day ( i live in the valley of CA) so idk if it will mess with its over all performance.

Thanks again guys for all the info so far i really appreciate it!

[Gjac]

After it warms up will it run well at high speeds for say 30 mins or does it immediately bog down when you press the gas pedal and never gets to hiway speeds? does it backfire through the carb or exhaust?

[Stim]

Tank venting system failing not letting tank breathe. ???
When it quits open gas cap and listen for vacuum.

[11178adm]

check the suction tube in the tank for a sock type screen on the end of the suction tube. with the age of the unit it could be plugged with rust and dirt and at some point in its life could have had some gas gone bade from sitting a long time

[rgatijnet1]

If you have a pump in the fuel tank, it will have an electrical wire going to it. Do not confuse your fuel gauge sensor wire with the electrical for the in-tank fuel pump.

[That1skater]

Thanks for all the reply guys!
I'll see about a new coil and will go through the rubber lines to see if any are getting too old,
I'll see if I can post a picture of the tank, all of my fuel lines from the tank come out the front(facing the back of the trans) the manual I have only shows a external pump as well.

[ksg5000]

Had an old Ford that has similar symptoms ... loose wire in ignition system. Everyone thought it was vapor lock etc .... real PIA to track down.

[time2roll]

Have you pulled all the spark plugs and they look great?
How much time and miles since the last tune up?
If it has the variable venturi carburetor consider just replacing it.
Backfire out the exhaust is generally too rich or ignition failure.
Lack of fuel... power will just fall flat on its face when you open the throttle.

[jdc1]

Have you checked the timing?

[atsrmf]

You may want to consider moving the ignition coil off of the engine and mounting it as far away as possible so it doesn't get so hot. I did that with mine and it runs great. Use a heat shield also, as the engine compartment gets hot as an oven.
I would post a photo of how I did that with mine, but I can't figure out how to post a photo on this site.

[atsrmf]

Drop the tank. Something may be plugging the fuel pick-up hose, or the hose has a crack allowing air in instead of gas. Replace all rubber fuel lines if you haven't already.
I have an '87 Gulfstream with the 460. There is a fuel pump in the tank, the relay is up front and is easily accessible.

[John_Joey]

jhgerhart wrote:
Ignition Coil? Sometimes the older ones heat up and fail until cooled.

This would be a good cheap guess. I would replace it, what you’ve described sounds a lot like what happens on very old outboard motors. You lose high spark when the coil gets hot. Still has spark but weak.

[Bruce_Brown]

Plugged catalytic converter?

Also, are you 100% sure there is no pump in the tank? Our 1990 had (2) pumps, (1) in the tank and (1) on the frame rail. Both were known to be problematic, we ended up replacing both for about the exact symptoms you describe. Seriously, you'd head out on a trip and it was a guessing game on if you'd make it or how long you'd go before it acted up. Not much fun, for sure.