Fuel pump cycles KOEO

Biggredd

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Hey guys This is a new one for me. Rough chain of events. First, car died on test drive after getting out of storage. Pump priming with no fuel to tail, turned out the fuel pump hose burst, so I changed entire pump (old one was rusty) and the sending unit which was bad too. Changed the fuel filter. The alternator had also gone bad (parasitic drain but no ac at terminals), so I replaced it. Now, with KOEO, the fuel pump primes for about 2s, cuts off and primes again, over and over until I start it or turn key off. Each time, relay clicks. If I start the car, it runs for 30 sec or so, then shuts down. The fuel rail stays at around 20psi. I thought it might be an old alarm that was killing ignition, but removed it and no change. Then the FP started the cycling thing after replacing the alternator. Engine has about 215000 miles on it.

I’ve searched, but can’t find anything on fp cycling like that. I’m leaning towards ECM at this point, but am at a loss. Any suggestions?

Edit: Almost forgot… 1996 base with 3.8. New to forum and mustangs in general. All my previous project cars were GMs. (86 firebird 76 Vette)
 

cobrajeff96

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What about the battery? Has it maintained charge all this time? I ask because your post doesn't mention anything about its current state. And on that note, a loose or rusty ground could cause such a symptom.
 

95opal

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20psi seems low is that with vac connected or vac off?
 

ttocs

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not many aftermarket alarms kill the ignition. They have a starter kill to prevent it from starting but not many have the ability to kill a running motor. I agree 20 psi is low. Check for voltage on the two wires going to the inertia switch in the trunk. Make sure they match
 
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Biggredd

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Thanks for the replies. It turned out the battery went bad as well. I had it tested 2 month ago and it was fine. The surging fuel pump was my jump pack cycling. I replaced the battery and now the car will start and idle for about a minute, then die. If I hit the gas, it will die. Fuel pressure is a bit over 10 psi with or without the vacuum on the regulator. The fuel pump now primes when KOEO the normal time, but fuel pressure never rises above 10 to 20. I guess everything has gone bad at once.
 

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