No Spark No injector Pulse?

Tiny
HASKINS64D
  • MEMBER
  • 2003 FORD MUSTANG
  • V8
  • 2WD
  • MANUAL
  • 38,000 MILES
I have tested all I can find to test, the power from the PCM is going to all the sensors I have tested such as IAT, TPS, Crank and Cam sensors all working properly, There is no spark and no injector pulse. I have found that the VSS has no voltage going to it though and the O2 sensors don't get a voltage to heat up when the key is turned on. I just changed out the engine so I suspected the cable that runs over the bellhousing to these sensors but I have found it to be seated properly. I can't find any other connectors that are loose bad or otherwise. Coolant temp sensor is good and getting voltage also. The fuel system primes properly and has pressure. If I order a PCM which I can't imagine why it would have gone bad. The car was running before I swapped the longblock.
The car is a Cobra with supercharger. Thanks for any help
Saturday, March 29th, 2008 AT 7:07 PM

16 Replies

Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Crank sensor OK? Does RPM needle move while cranking? If not I have seen the PCM go out which causes this issue. Also a bad CCRM relay unit.
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Saturday, March 29th, 2008 AT 7:31 PM
Tiny
HASKINS64D
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The Crank and Cam sensors are good I just rechecked the voltage going to them, it's supposed to be battery voltage and there is none. No battery voltage too either of them and I'm realizing now that it is supposed to be battery voltage to the O2 sensors and there isn't any.

As far as the tach. The needle doesn't move when cranking but I'm not sure it's supposed too.
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Saturday, March 29th, 2008 AT 8:21 PM
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
It is. And check the sensor while cranking, it should put out more than.1 volt.
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Sunday, March 30th, 2008 AT 6:55 AM
Tiny
HASKINS64D
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  • 14 POSTS
I have checked the crank pos and cam pos sensors when turning the engine and they show a voltage change meaning to me that they are working. But the voltage going to them isn't there. Does the power come directly from the PCM? Or does it go through a relay? I did pull the instrument cluster durning the install but it only has two plugs and a boost line. I'll recheck the plugs and see if there is a problem.
Thanks for your help
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Sunday, March 30th, 2008 AT 10:13 AM
Tiny
MERLIN2021
  • MECHANIC
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Have you scanned for fault codes yet?
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Sunday, March 30th, 2008 AT 4:30 PM
Tiny
HASKINS64D
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  • 14 POSTS
Since I have had the battery out. Now there aren't any codes stored. I found out that pins 21 and 22 on the PCM are the two that go to the crank pos sensor. So I checked the voltage with the key on engine off comming directly out of the PCM and there isn't any it's 0.0 volts. Is there anything external to the PCM that would cause this?
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Sunday, March 30th, 2008 AT 7:40 PM
Tiny
HASKINS64D
  • MEMBER
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I had some bad information, The Haynes Repair Manual described how you would have battery voltage going to the ckp and the cmp. But I read just now in another manual that two wire sensors don't have voltage going to them that the pcm just reads the voltage fluctuations coming off of the sensor. Only the three wire sensor has voltage going to it. So Im back too where I was on saturday?
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Monday, March 31st, 2008 AT 8:08 AM
Tiny
MERLIN2021
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Next you'll need to check the CCRM, both the fuel pump relay and the PCM Power relays are built in to the CCRM, pull it out and check for any burnt wires or bent pins...


https://www.2carpros.com/forum/automotive_pictures/62217_Relaysa_1.jpg



https://www.2carpros.com/forum/automotive_pictures/62217_Relaysb_1.jpg



https://www.2carpros.com/forum/automotive_pictures/62217_Relaysc_1.jpg

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Monday, March 31st, 2008 AT 1:17 PM
Tiny
HASKINS64D
  • MEMBER
  • 14 POSTS
I pulled every relay and tested it with an ohmeter and gave them power to verify they are all operating properly.
I ohmed out all the sensors and found one to be a little different than what a book said it was supposed to be. But I'm not sure if the reference is correct. I found the VSS sensor to have 1100 ohms and I read that it was supposed to have 150 to 250. Like I said I don't know what's right. It does give up to a.5v ac when running a screwdriver across it's face.

I find that the MAF is getting the Vehicle voltage it's supposed too and same with the TPS and engine coolant sensor.

I did verify today that I have continuity from the PCM too the transmission harness. That was in question till today. Now I know the harness is good and connected.
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Monday, March 31st, 2008 AT 6:53 PM
Tiny
HASKINS64D
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I found the data for the VSS and Mine is good. The resistance is 1020-1210 Ohms at 25C and mine is right at 1100. I am now looking toward the PCM
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Monday, March 31st, 2008 AT 10:47 PM
Tiny
MERLIN2021
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If it's not powering the sensors might be the problem. What does the security light on the das do with key on and cranking?
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Tuesday, April 1st, 2008 AT 2:55 AM
Tiny
HASKINS64D
  • MEMBER
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I checked my tune and then looked at my real time data log on the predator tuner. With the key on I got these results. Then changed the Crank Sensor. Then the same results than changed the Cam sensor. And same results.

0 RPM RPM
76F IAT
40 PSI FRP
10 DEG SPRK ADV
74.6% LOAD
OPEN FEEDBACK FUEL CTRL STATUS
70F ENG COOLANT
72F INTAKE AIR TEMP 2
-62% SHORT TERM FUEL TRIM BANK 1
-62% SHORT TERM FUEL TRIM BANK 2
0.99V TRHRT POS BEFORE FMEM SUB

When engine turns over you can see the Fuel pressure rise and then go back to 40 and when you depress the throttle you see the voltage to up to 5v. You just have no RPM when cranking Thats where I'm at now. And I changed sensors and still the same results.

The theft light is normal (not flashing) and the milage is displayed normally.
I'm wondering if it's possible that the Gear that goes past the crank sensor is missing. If the guy that built the engine could have possibily not installed it.
Or the computer isn't recognizing it anymore. And is bad.
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Wednesday, April 2nd, 2008 AT 12:46 AM
Tiny
MERLIN2021
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Yes that's possible, or somehow the air gap isnt right. But you said you were getting volts out of it while cranking?
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Wednesday, April 2nd, 2008 AT 2:54 AM
Tiny
HASKINS64D
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I just verified yes I have voltage out of the CPS and it gets all the way to the PCM. It is 0.2 volts while cranking. But while data logging the RPM reads 0.
So what else could it be other than the PCM
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Wednesday, April 2nd, 2008 AT 8:48 AM
Tiny
MERLIN2021
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Check the ignition switch injectors are powered by the switch during cranking. Also check the ground at the left front of the engine compartment, that's ground 104 for the injectors.
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Wednesday, April 2nd, 2008 AT 1:11 PM
Tiny
HASKINS64D
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Wow I found the problem today ! Unfortunately I just bought a PCM and didn't have to use it and it's non returnable. Had I known what the voltage should have been out of the Crank Position Sensor while the engine was cranking over I would have been able to pinpoint the problem. I did see today that if you turn over an engine by hand with a wrench without sparkplugs in it you can get about .4 VAC out of it. The engine I put in was getting.2 vac out if it when the starter was turning the engine over.

I pulled out the Crank Position Sensor and looked with an inspection mirror and saw that the Crankshaft sensor tooth wheel isn't the correct one or has been modified. The engine was setup to be run in a restomod project with FAST computer system the sensor wheel has maybe 4 to 6 teeth on it instead of the normal 35 teeth. Thus the normal timing isn't being sent to the computer. Thanks for the input or thought you have put toward this problem. If you have any questions about my project just ask.
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Sunday, April 6th, 2008 AT 9:36 PM

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