Mechanics

FORD F-150 SPARK PROBLEM

2002 Ford F-150 • 168,593 miles

I have the XLT Triton v-8 4.6, for past two weeks I have been having to put key in ignition leave it on for 5min then it would start. But now it won't even turn over. I sprayed starting fluid in it and started like that for couple days but now I'm back to nothing. The fuel pump in gauges, the fuel filter is clean, I have excellent fuel pressure, and the truck shows no codes. Oil level is good, mass air flow sensor has been changed and all coil packs and spark plugs have been changed, and the IAC has been cleaned as well, please help.
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Alisonrasberry
March 10, 2013.




Lets start with the fuel pressure? What is the exact fuel pressure?

Roy

ASEMaster6371
Mar 10, 2013.
43 @ ridge

Tiny
Alisonrasberry
Mar 10, 2013.
Is the theft light blinking or on steady when the key is turned to the ON position?

Also try disconnecting the battery cable for at least 10 minutes (some people suggest at least one hour), reconnect and see if it cranks. If so, suspect the PATS (anti-theft) system.

Freemba
Mar 10, 2013.
I did disconnect battery for 30min 2 days ago, do you think I'd have to do it again?

Tiny
Alisonrasberry
Mar 10, 2013.
And if this is problem how do I fix it?

Tiny
Alisonrasberry
Mar 10, 2013.
No. I don't think that disconnecting it again would be any different from the last time. The security light should go out a couple of seconds after the key is turned to the ON position. It should be steady, not flashing. Is that the case?

Also, check for a spark at the spark plugs, when cranking the engine(if you haven't already).

How to check for a spark DIS system
1. Disconnect a spark plug wire at the spark plug end.
2. Connect the plug wire to the spark tester and ground the tester to an appropriate location on the engine. (If you don’t have a spark tester, put a screwdriver into the spark plug end of the wire and lay it on the engine so that there is at least a ¼ inch gap between the metal part of the screwdriver and a metal part of the engine)
3. Crank the engine and check for the presence of spark, and also the intensity at the tester. (Or a spark between the screwdriver [metal part] and the engine)
4. If spark exists at the tester (or screwdriver), the ignition system is functioning properly.
5. Repeat the procedure on at least one of the remaining spark plug wires.

Freemba
Mar 10, 2013.
How do I fix or bypass PATS?
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Tiny
Alisonrasberry
Mar 10, 2013.
Well before we get to bypassing anything let's narrow down the possibilities.

1. Does the ignition system produce a spark when you try cranking the engine?
2. Is the theft light blinking or on steady?
3. Does the engine now start when you use starting fluid or carb/choke cleaner?

Freemba
Mar 10, 2013.
No does not start with starting fluid, disconnecting battery for ten minutes made it start. Anti theft blinks even when key is out of ignition for 20min

Tiny
Alisonrasberry
Mar 10, 2013.
Have you tried starting it using the spare key?

Also, try jump starting it. I know that the battery turns the engine over, but sometimes the battery will have enough power to turn the engine but not enough to fire the coils or operate the injectors (weird I know, but its' happened before on these). I know it's a long shot but the alternative is listed below.

If you have tried both keys and disconnecting the battery for 20 minutes then retrying with both keys then there is nothing else you can do. A ford IDS scanner will be needed to clear and reprogram the keys to the vehicle. For whatever reason the key programming has been cleared and if it won't start after a 20 minute battery disconnect with either key it will need to be reprogrammed with an IDS scanner. Unfortunately this will involve having the vehicle towed to the dealer.

Freemba
Mar 11, 2013.

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