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2000 Crown Vic Cranks but won't start

1923 Views 93 Replies 7 Participants Last post by  R.S.LOGAN
Hello from Louisiana y'all
I have a 2000 Crown Vic LX 4.6 L Windsor
Recently the intake manifold cracked and of course blew coolant everywhere
It actually cracked at the fitting where the coolant temp sensor was, yes I said was. It blew the sensor out of the fitting.
Of course I pulled the old manifold off and replaced it
Fairly simple and straightforward right?
Now, the engine was running before the intake replacement.
Now, with the new intake and various other items, thermostat, upper radiator hose, and spark plugs, all of which it needed anyway, it will not start.
First obvious check, fuel pressure. Bingo right at 35 PSI
Next, code check, No codes
Next, spark, no spark, power at the coil leads
Next, injector pulse, No pulse, power at the injector leads
First thought, crankshaft position sensor, Just put a new one in, not without much agony and colorful expressions.
Still no start, no pulse, no trigger voltage at the coils.
Scan for crankshaft position sensor RPM when cranking. The ECU is getting a signal from the sensor.
All fuses and relays appear to be operating as expected, either by testing with a test light or by swapping known working relays.
Still no start.

If anyone has any suggestions on where to go next, PLEASE let me know.
Thank y'all so much
Chris Ellington
21 - 40 of 94 Posts
I'd also like to add: what's the voltage reading at the PCM?
Hey again Dave
Yep I think the PCM is dead after 23 years of great service
I went ahead and put a new camshaft sensor in and put a better ground on the little one that was on a fuel rail stud
Still the same result
It’ll try to start but it won’t
I’ll look into testing the ECM
Thanks for your help
I’ll let you know what happens
I was also curious if I can bypass or disable the PATS on this car
Hi Dave
I just ordered a new computer for the Crown Vic
It was fairly cheap
I was curious though
When the new computer is installed am I going to have to play with the PATS system?
I hear different stories about this
Some say no
Other say I’ll have to get it reset or reprogrammed
I had a friend of mine replace my intake once and I had the same problem, it turned out he pinched some wires in the rear of the intake and forgot the grounds in the back. He also cracked the plastic throttle switch when he dropped the throttle body. It would pop the first time, then crank with no start. My lincoln towncar had a crank but no start once, it was corroded relay terminals in the underhood fusebox. Worth looking at, I don't know.
Merc49
Thanks for the info
I’ve checked and rechecked the wiring and the ground straps
So far nothing is pinched or disconnected
I’m getting power at the ECM relay power at the coils and injectors
I’m getting a pulse on the injectors and an RPM reading on the scanner
Looks like that might be an issue. The ECM might have to be reprogrammed to accept it.
One way to find out, though.

ECM/PATS Ford
I'd also like to add: what's the voltage reading at the PCM?
Sorry Dave
I missed this question
I’m not sure what it is
Are we talking main power to the ECM going in or the individual power output to the coil feeds?
Maybe the switch signals out to the coils?
I’ll need a wiring diagram of the ECM to check individual circuits
Thanks so much for your help
Not quite following...are you saying you've got it running? Or that it is still not running but everything is connected as before?
Since coolant sprayed over the engine controls, you may want to check the throttle position sensor. If fouled, it will not allow the engine to start.
Since coolant sprayed over the engine controls, you may want to check the throttle position sensor. If fouled, it will not allow the engine to start.
CJF
Thank you for your help
I’ll take a look at that too
I don’t think the coolant sprayed that far back but anything is possible with the cover on top of the engine
I owned a 2000 Mercury GM that stranded my wife with a bad TPS. It would crank but not start. I recall the sensor functions on variable resistance and can be checked with a ohm meter.
CJF
Thank you for your help
I’ll take a look at that too
I don’t think the coolant sprayed that far back but anything is possible with the cover on top of the engine
CJF
Just out of curiosity I put the scanner on the Vic and did a specific test for the TPS
It’s getting .94 volts at closed throttle and 4.5 volts at WOT
The scanner also reports no fault with the TPS
TPS voltage sounds about right.
As for the ECM, I was talking about any power lead supplying the ECM itself.
TPS voltage sounds about right.
As for the ECM, I was talking about any power lead supplying the ECM itself.
Hey Dave
I’m pretty sure there’s power to the ECM
I have power to the scanner power everywhere else
If I wasn’t seeing power to the computer I’d suspect that too
Hey Dave
I’m pretty sure there’s power to the ECM
I have power to the scanner power everywhere else
If I wasn’t seeing power to the computer I’d suspect that too
My question was: How much power? What's the actual voltage reading on each supply lead?
My question was: How much power? What's the actual voltage reading on each supply lead?
ahh got it
I’ll need a schematic for the ECM inputs and the expected voltage if possible
Thanks
Should be full 12 volts at the ECM connector.
Should be full 12 volts at the ECM connector.
ok cool
Which wire/wires am I looking for?
Pin out or color please
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