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Glenn, Senior Master Ford Tech
Category: Ford
Satisfied Customers: 1746
Experience:  26 years exp with Ford Products, ASE Master Auto & Truck + advanced engine perf L1/L2 Gas & Diesel
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98 explorer cranks won;t start,ecm turns the fuel pump briefly,cam

Customer Question

98 explorer cranks won;t start,ecm turns the fuel pump briefly,cam sensor new,ign working no active codes,
Submitted: 7 years ago.
Category: Ford
Expert:  Glenn replied 7 years ago.

hello there,


Find the test port for fuel pressure on fuel injector rail, looks like a tire valve with blue cap if still present. It would be best to test the pressure, should be around 70 psi and hold for a few minutes. [at least depress the valve to see if fuel squirts up.. You could also spray some carb cleaner into throttle body to see if it wants to start then, this would confirm a lack of fuel. How old is fuel filter?

Edited by Glenn on 12/22/2009 at 3:07 AM EST
Customer: replied 7 years ago.
no the fuel pump doesn't come on no fuel pressure, the fuel pump relay and roll over switch work, the ecm briefly sends a signal when the key is turned on ,and if you power up the fuel pump it still won;t start ,
Customer: replied 7 years ago.
did you get my respond ?and can the alarm shut down(or not let the engine start ) if so does it shut down the fuel pump circuit ?
Expert:  Glenn replied 7 years ago.
The pats system can, [coded key] but the theft light should be flashing if this were the case. Sounds more like a defective fuel pump, can you hear it run? did you get any fuel from rail?
Customer: replied 7 years ago.
when the key is first turned on the fuel pump comes on for 1 second ( i can power up the fuel pump at the roll over switch , using a power probe ) and the engine still won't start, which leads me tord the anti theft, and yes the anti-lamp is flashing and i asked the owner and she doesn't remember if it flashes shen she startes it and that is when i got involved, so what compontes are in the theft circuit, should we test the circuit to rule it out?
Expert:  Glenn replied 7 years ago.

if your powering up fuel pump circuit,do you have fuel pressure at this point? The pump should run if jumpered, do you hear it?

Try a different spare key if theft light flashes rapidly when attempting to start, this would indicate the pcm is locking out fuel/ This would need a computer scan tool to be able to pull codes from pats module, and check to see if its getting enable signal or not... an obd2 code reader will NOT work for this.

Customer: replied 7 years ago.

when i power up the fuel pump i have fuel pressure,and the engine doesn't start, cranks but doesn't start, when you first turn the key on the fuel pump comes on for 1 second, what does parts stand for and how does the theft shut down the engine, ( fuel pump, injectors ? )

Expert:  Glenn replied 7 years ago.
It will shut down the injector pulse and fuel pump.. also spark on some.. they have changed this up on different model years and I can not remember them all and shop manual is vague. Like I said there is not much you can do with out scanner, check all the fuses and try cycling key from off to on a dozen times or so in a row with out cranking, see if that theft light will go out.
Customer: replied 7 years ago.
sounds like we found out the theft devise is the problem do you know of or can get ahold of the schmetic and/or the components since i only have a scanner (from auto zone )
Customer: replied 7 years ago.
how can i or do you have a schmetic for the factory alarm and /or compontents
Expert:  Glenn replied 7 years ago.
I will get that to you, its not going to do you much good though.
Glenn and 4 other Ford Specialists are ready to help you
Customer: replied 7 years ago.
thankyou can you please send it to [email protected] and again thankyou matthew
Expert:  Glenn replied 7 years ago.
Customer: replied 7 years ago.
is there any way to reset the alarm system ( i cycled the key on and off 10 times with/out starting the engine )
Expert:  Glenn replied 7 years ago.
No reset, its not reading the key properly. They are a pain to diagnose even when you have the proper equipment and shop manual.