68 GTS won't stay running

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Replaced pump, still does it.

Here is a list of everything replaced:

Carb
Filter
Pump
Coil
Spark plugs
Wires
Checked tank and sending unit
Voltage regulator
Ballast resistor

I can conclude fuel is not the issue. Could it be the magnetic pick up in the distributor or the ecu? The ecu was replaced a few years ago. 4 pin orange.
 
Jimmy428 said:
Replaced pump, still does it.

Here is a list of everything replaced:

Carb
Filter
Pump
Coil
Spark plugs
Wires
Checked tank and sending unit
Voltage regulator
Ballast resistor

I can conclude fuel is not the issue. Could it be the magnetic pick up in the distributor or the ecu? The ecu was replaced a few years ago. 4 pin orange.
Click to expand...

the ecu needs metal on metal contact with the body to work properly. have you checked the reluctor gap in the distributor? .008 with a non magnetic feeler gauge. re check every ground . battery to block to body. sorry if missed any of this in your thread , i didnt go read the whole thing. if you have another ecu , it easy enough to try one. pickup coils do go bad , but ive never had one that has.
 
I will try that. All grounds look ok to me visually. Even scuffed me up and reconnected. Gap is .008" rechecked. I will buy p5153576 and see if that works. The ecu and coil do not get warm to the touch. I don't have testers to check specifically ohms or resistance so I'm just gonna keep replacing until everything is new :dontknow:
 
Jimmy428 said:
... I don't have testers to check specifically ohms or resistance so I'm just gonna keep replacing until everything is new :dontknow:
Click to expand...
Gets real expensive unecessarily real quick doing it that way. A lot more than a digital multi-meter would cost. You need to verify whether or not you have spark when it dies out or if you don't have fuel. I have to laugh at some of the suggestions & theories on why the peoples cars gave them trouble. A little diagnosis will go a long long way & help keep the costs down. Invest in a cheap spark tester & a meter. You can probably get both for under $40 at Sears.
 
What intake/carb do you have ? I saw replaced carb. Dont know what it was before either.
I didn't exactly figure out the empty fuel filter on mine. What puzzled me the most was, Were does the air come from that fills the filter as the fuel goes out of it ?
I did 3 things at one time and solved the problem. I put a fuel line from a 73 model that located the filter vertically and down near the fuel pump. I put a metal filter there so IF there is any air in it.. I'll never see it.
Then I installed a phenolic spacer listed for a 75 model. When I pulled the carb to install this spacer I realized I had accidently stretched the accelerator pumps linkage rod last time I had the carb off. Result was the pump wasn't returning to the top and opening the bowl vent like it should. My theory was the air appearing in the clear filter was coming back from the bowl. Air pocket moving back and forth ? Anyway... Corrected accelerator pump linkage, adjusted the choke rod height to the spacers change.
One or all of these things fixed it. Absolutely no hard start or running problems of any kind since.
Then the front seal in the trans started leaking. One dang thang after another. Good luck with yours.
 
Single plane weiand accelerator with a holley dp 600 cfm. Replaced with single feed 600 cfm. Old one leaked everywhere and fixed upon rebuilding but wanted to rule out warped blocks. Going to go back to dp because for some reason when it is running I can't get rid of a horrible lean spot. It was perfect running with the dp until the cutout problems started.

Thanks I will just fool with it until its fixed.
 
There's no spark from coil immediately after dying. Something is not operating after warming up.
 
I think if it was electrical there would be some other symptom. Fail to start when cold or some other clue to where the fault occurs.
Could be the ignition switch loosing a connection I guess. In order to get the right voltage out of a ballast resistor you have to have the right voltage going in.
The 2 wires and connectors to the pick up coil are suspect since they aren't protected and wire will change position with temperature change.

Has anyone suggested spark timing set too low ?
 
Are you certain your coil is good? I had the exact problem with a 340 Barracuda, A new coil fixed the problem. Coils can work fine when cold but then break down and fail when warmed up. If I remember from reading this thread, you changed the coil.......Make sure you got a good one. That would cause your no spark issue described above.......

Russ
 
Finally!!!!!!

It ended up being the ecu. Thank you all for the guidance.

:blob:

:burnout:
 
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