i have 91 F 150 4.9 ENGINE . It will crank and run fine then just goes dead . If i switch tanks it will crank back up and run fine , then you drive for a while and it goes dead again .
if i'm running the front tank it runs fine for a while , then dies . i switch to the rear tank , it runs fine for a while then dies . i switch back to the front tank and it cranks back up and runs fine . It repeats this process ,
It sounds like you may have two bad fuel pumps. But what is the chance of that? If you can force it to malfunction in the driveway immediately run a fuel pressure check on the offending tank, then the other. It's going to be a process of elimination in a no run condition.
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