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1989 LX 5.0 Cranks but won't start after sitting a few weeks

1021 Views 6 Replies 5 Participants Last post by  Shawnryan
Just trying to figure out what I should be looking for.

Car had alternator upgraded to 150amp recently by local Mustang shop and had the P/S pump pulley replaced with a larger diameter pulley to stop the tensioner pulley from rubbing against the W/P pulley. The oem starter was starting to seize up, so it was also replaced with a hi-torque ministarter from LMR. All cables were upgraded as well as the starter solenoid. It was starting and running fine when I brought it home (1st week of December 2022).
Fuel tank was under a quarter tank, so I filled the tank with 93 oct, added some stabilizer and put it to bed. It has a Vortech V1.

We had some nice weather this past weekend up in southeastern MA, so I tried to start it. It cranked strong but wouldn't start. I could hear the fuel pump kick on when the key was moved into ON position, as expected. Visual inspection under the hood didn't reveal any loose, disconnected or CHEWED wires (i.e. rodent damage).

Injectors are all brand new. If this was my tractor, my first guess would be that it wasn't getting fuel and I'd likely suspect my carburetor had gummed up from letting the gas sit in it for a few weeks even with the stabilizer (damn ethanol). But this ain't my tractor and this engine doesn't have a carburetor, so I'm looking for suggestions on how to troubleshoot this, given I can hear the fuel pump running.

A few other things to note:

  • I have no idea when the fuel filter was replaced last;
  • I don't know when the last time the plugs were changed;
  • I bought the car with 74k this past August. It's been dyno'd and tuned since and fuel pressure checked out fine, and wasn't made aware of any spark issues.
  • I don't own a fuel pressure gauge.

1 - 1 of 7 Posts
so I'm guessing the fuel sending relay is shot also
The sending unit is actually a variable resistor.
The suggestion to spray carb cleaner or starting fluid in the intake is a good way to tell if it's an ignition issue or a fuel issue.
The PIP sensor and TFI module are common ignition killers in the old fuel injected 5.0. When the TFI module starts to fail it's known to give starting problems especially when it gets hot but it can fail at any temperature. I believe a failing PIP sensor will also give problems when it gets hot but it will tend to stall out a running engine rather than keep it from starting but it can also just die completely at any time.
It should be noted that cheap aftermarket brands usually fail in short order so if either one of these are the issue don't buy generic crap to replace them.
If it's an ignition problem then another possibility is a bad ignition switch. Many Ford cars from this era had a recall for the crappy design of the ignition switch. My 1993 had it replaced at some point before I bought it but the replacement also loosened up and failed. I believe that Ford seemingly never redesigned the switch and just replaced them under recall with the same junk design. Either that or the redesign just wasn't any better than the original design.
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