no injector pulse

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Feb 20, 2007 | 06:20 PM

patho44

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Cross-Country

Joined: Dec 2006

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From: Prairie Village, KS

no injector pulse

got gas, got fuel pressure, got a good battery, got 12v to the injectors, engine fires immediately with a shot of ether in the intake and then dies just as quick, but got no injector pulse. no fuel to the cylinders; what are the causes of no injector pulse Other than a defective PCM. thanks.

Feb 20, 2007 | 09:12 PM

patho44

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Cross-Country

Joined: Dec 2006

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From: Prairie Village, KS

the vehicle I am working on is a 99 exlplorer 4 ltr sohc, 4x4

Feb 21, 2007 | 03:34 AM

aquanaut20

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Joined: Aug 2003

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From: BC Canada

check the crank sensor connection

Feb 21, 2007 | 03:37 AM

87 XLT

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Joined: Oct 2003

Posts: 4,516

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From: SoCal

Yours should be the same as my 97 & heres what the 97 EVTM sez about firing the injectors:

"The cam position sensor supplies number 1 cylinder top dead center information to the PCM for use during engine start up to begin sequential pulsing of the injectors."

Pull the codes & see if you come up with a code P0340/cam position sensor circuit fault.

Feb 21, 2007 | 05:31 AM

87 XLT

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Joined: Oct 2003

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From: SoCal

Quote:

Originally Posted by aquanaut20

check the crank sensor connection

OOPS, thats right, on the newer engines the spark & injectors are both timed by the crank sensor.

Not sure when Ford changed it.

Bottom line is to pull the codes.

Feb 21, 2007 | 10:11 AM

patho44

Thread Starter

Cross-Country

Joined: Dec 2006

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From: Prairie Village, KS

thanks.....the manual does not describe how to test the crank sensor or camshft sensor.... ?? the connections look good.

Feb 22, 2007 | 09:07 PM

patho44

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Cross-Country

Joined: Dec 2006

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From: Prairie Village, KS

the code scanner displays the message ..... no trouble codes available the manuel for the scanner states that if no troubles codes are found the message .... no trouble codes found will display. the vehicle sat with a dead battery for a while...could that have cleared out any trouble codes from the pcm?

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Feb 23, 2007 | 02:12 AM

87 XLT

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Joined: Oct 2003

Posts: 4,516

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From: SoCal

Take a look at your wiring diagram for the ignition circuit. Is there a crank sensor in that circuit?

Now take a look at the engine controls wiring diagram. Is there a cam sensor in that circuit?

Or plan B, take a look at the rear of the engine is there a cam sensor plugged in where a distributor used to be?

Since it fires on the starter fluid, it sounds like you have a good crank sensor & a defective cam sensor.

The PCM cant pulse a ground to the injectors if the cam sensor is shot.

I have an Actron sensor tester that will test a cam sensor at cranking speed in a few seconds.

Wish I had the 99 factory wiring diagrams/EVTM, so i could see what setup yours has as far as crank sensor only OR crank & cam sensor.

Edit, yeah the codes will go away with a dead battery.

IS your scanner able to look at live data, like the output from the cam sensor? If yours has a cam sensor.

Last edited by 87 XLT; Feb 23, 2007 at 02:36 AM.