1993 Ford Thunderbird excessive cranking before starting

Tiny
GARY KINCHEN
  • MEMBER
  • 1993 FORD THUNDERBIRD
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 220,000 MILES
HELP. I own this t-bird and my son has it at college. We have babied it and never sacrificed repairs. We now have this condition that can not be fixed as Meineke keeps throwing parts at it. They replaced fuel injectors, all the plugs did a full injector flush and service, didnt fix it. Then they said it was fuel pump, pump relay and fuel filter, didnt fix it. It cranks for 15-30 seconds and then starts. They then said it was the fuel relay valve had a crack and sucking air, fixed the engine light from coming on but still not the long start. This car gets 30/mpg is solid and straight but the parts replacers are running out of parts. The car is in colorado srings and I am in indiana cant get their myself and my son being at the academy has little time to keep running. COIL? Maybe?Vacuum hoses? We need help this is frustrating after $850 which is still cheaper than a new car. Cars start cars go Meineke is clueless. HELP if you can
Thursday, April 24th, 2008 AT 4:19 PM

2 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Usually it's fuel or vacuum related, fuel pump has been done so lets go to Vacuum, Some Fords when the IAC is a bit sticky, can cause extended cranking, or even a clogged PCV, or cracked PCV hose, if it's more when cod, the engine coolant temp sensor, and or Intake air temp sensor, these can be checked by a scan tool that can read the degrees, check these two sensors in the AM before the first start, they should be within 10 degrees of each other. Ford did have a tech bulletin on the Idle air control, not sure if your year was included.

See probable causes:

1. A dead fuel pump (could be the pump, pump relay or wiring circuit);

2. A plugged fuel filter;

3. Low fuel pressure (weak pump or restricted line); or

4. No pulse signal to injectors (bad injector relay or PCM driver circuit).

One of the first things to check is the fuel pump. Does the pump run when the engine is cranking? The pump should make a little noise. No noise would tell you the pump is not spinning.

On most vehicles the pump is energized by the PCM via a relay. The pump circuit also may be wired though an oil pressure switch and/or an inertia safety switch that kills the pump in case of an accident. Refer to the wiring diagram to find out what is involved before jumping to any conclusions.

Other electrical problems that can affect the pump include low voltage in the pump's power supply circuit or high resistance in the pump's ground connection. Either may prevent the pump from running or spinning fast enough to generate normal fuel pressure.

Vacuum leak/coil/ignition control module/distributor pick-up coil
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Thursday, April 24th, 2008 AT 5:25 PM
Tiny
BLACKOP555
  • MECHANIC
  • 10,371 POSTS
Have a fuel pressure leak down performed on it, if it shows a drop in fuel pressure then I would check all lines for holes, if thats not it check the fuel pressure regulator and make sure the check valve is not leaking off pressure due to a bad valve or cap.

If the fuel pressure doesnt leak down its not fuel related.

Get back to me.
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Thursday, April 24th, 2008 AT 5:32 PM

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