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Discussion Starter · #1 ·
working on a 97 mountanier 5.0.....ten to twenty second crank times. fuel pressure is in spec as soon as you turn the key on. no injector pulse or spark initially. it spins and spins until pulse and fire shows up then it runs awesome. any thoughts would be appreciated. ive swapped relays around to eliminate the possibility of a lazy relay.
 

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Vehicle Application: 1999 Mercury Mountaineer 5.0L, Vin P, Eng Cfg V8 

Customer Concern: Need to know the fuel pressure specifications. The engine has an extended crank time, suspect low fuel pressure is the problem. 
Tests/Procedures: 1. This is a mechanical returnless system, so the fuel regulator is in the tank.

2. Fuel pressure specifications are 40-65 PSI and the pressure should hold Key On Engine Off (KOEO). 
Potential Causes: Information Only

Diagnostic Codes: None 

Confirmed Fix Summary   

Confirmed Fix 1 -  Crankshaft Position (CKP) Sensor
1 -  Fuel Pump Assembly


 

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Discussion Starter · #4 ·
ive noticed that oil pressure gauge on dash jumps to normal after just a few seconds of spinning. separate oil sender for the computer? vehicle does run good after initial long crank. it holds at least 35-40psi during the long crank. i didnt look up spec i figured usual ford mpfi 35-45psi for my spec. it lacks injector pulse and spark for the entire ten or twenty second cranking then all of a sudden youll see them both start flashing and boom she fires off???????
 

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The dash gauge on these vehicles is actually just an idiot light/trip switch.  You should notice it will shoot to the center and never move.  I read it can be modded but otherwise it is either "on" with the pointer fixed (and I think 10-15 psi is the trip point) or off.  I don't think it affects the computer (can't confirm) but there is only 1 sender.
 

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s ǝoɾ said:
Those later motors use a cam sensor up front where the distributor used to be on older 5.0s?
Yes they do, and they use a distributor base/shaft to actuate it. I was going to suggest that as another possibility. It is a common enough failure in those engines.
 

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Discussion Starter · #9 ·
can a cam sensor hold the essentials back for so long? refers to some kind of limp mode or something? some sort of preset parameters? why the delay? its a delay thats so long im gonna end up having to hang a new starter on it.
 

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Why put a starter on it? This one obviously works.  ;D  (I have been known to use a digital tach to verify it was cranking over fast enough, sometimes the difference in speed is not audible)

How have you tested for injector pulse? Noid light? Logic probe?
 

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Discussion Starter · #11 ·
the engine doesnt spin faster all of a sudden and crank........???????? in my first article of this topic it was stated no inj. pulse or spark during the long crank
 
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