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Home / 87-93 Mustang Will Not Stay Running Can Bad Alternator

87-93 Mustang Will Not Stay Running Can Bad Alternator

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Car will not stay running

  • Thread starter Diocletian
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Diocletian
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  • Thread starter
  • #1
Exactly what the title says. It will crank, start and die immediately, no stored codes or any errors. Full accessory power with the key in the ON position and battery is in good condition.

Before this started, I switched my tune file(Lund) back to Flex as I wanted to drop back down to 93(constant issues with E85, long story). The tune switch went as normal, as it has many times before. Now when I try to start the car, it will turn over and sputter out. I have enough gas in the car too, 18 miles to empty according to the gauge.

At a loss here, anything else I should be checking?

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  • #2
Have you tried to load the stock tune back in?
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  • #3
Check your fuel pressure, sound like your pump may be bad
Diocletian
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  • #4
Have you tried to load the stock tune back in?
I don't want to do that as there's only E85 in the tank
Diocletian
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  • #5
Check your fuel pressure, sound like your pump may be bad
Fuel pressure looks fine, I can hear it prime too.
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  • #6
Hmm see if your tuner can send you a new tune to load something may be going on there
Andy13186
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  • #7
Switch to a 93 tune id say
Diocletian
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  • #8
Switch to a 93 tune id say
The problem is I have E85 in the tank, that would cause more issues
Andy13186
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  • #9
stay on e85 tune until you are empty, then fill with 93 and load 93 tune
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  • #10
Consider checking the maf sensor for the cold air intake, maybe it is upside down? I'm not a car expert. FYI. Just throwing in my 2 cents
Andy13186
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  • #11
I am curious what company e85 tune you have and what issues you have?
Diocletian
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  • #12
I am curious what company e85 tune you have and what issues you have?
Lund and I've been having idle surging issues, after a year of diagnosing they are now fixated on my MAF being the issue
Diocletian
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  • #13
Consider checking the maf sensor for the cold air intake, maybe it is upside down? I'm not a car expert. FYI. Just throwing in my 2 cents
Can you take a picture of your MAF? I'm wondering if that is the issue, I bought the car brand new a year ago and that would be wild if it was installed wrong at the factory.
Andy13186
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  • #14
Lund and I've been having idle surging issues, after a year of diagnosing they are now fixated on my MAF being the issue
I have minor idle surging on my PBD tune but only before I give it any throttle at all after a cold start. But I do have my idle go rough on e85 occasionally, it also went rough on the stock tune though and on 93 octane so IDK what to think.
Bikeman315
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  • #15
My 15EB had the same issue. Was lucky I got a tech that was a excellent troubleshooter. It was a loose wire under the rear seat that blew the fuel pump fuse.
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87-93 Mustang Will Not Stay Running Can Bad Alternator

Source: https://www.mustang6g.com/forums/threads/car-will-not-stay-running.131371/