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91 Crown Vic 5.0L won't start


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harleyguy
User

Aug 31, 2005, 10:06 AM

Post #1 of 12 (3663 views)
91 Crown Vic 5.0L won't start Sign In

OK guys, put your thinkin' caps on for this one. I picked this car up after it sat for a year. Cleaned and reconnected EVERY electrical connection in the starter circuit. New plugs, new wires, new cap, new rotor, new battery. Purged all old gas and put fresh gas in tank. Pressure good on the rail. good spark on the plugs. shot starting fluid in intake, still not even a sputter. motor turns but seems slower cranking than usual. Car ran before stored. I am guessing that even though we have pressure on the rail, the fuel is not completing the trip. Any help would be appreciated. e mail me at rhoffman@switch.com with your ideas. thanks.


Tom Greenleaf
Ultimate Carjunky / Moderator
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Aug 31, 2005, 10:37 AM

Post #2 of 12 (3661 views)
Re: 91 Crown Vic 5.0L won't start Sign In

You have all the right ingredients and NOT a sputter?? Ok - the 5.0 can eat the relay to EEC which should have a brown connector. Other common thing is the gray module on the side of the distributer. Takes a spechial tool for two silly bolts to remove and replace it. Just some guessing, generally you wouldn't have spark if either of the mentioned were bad?? Good luck, keep at it and let us know what solved it.



harleyguy
User

Aug 31, 2005, 10:43 AM

Post #3 of 12 (3659 views)
Re: 91 Crown Vic 5.0L won't start Sign In

Thanks Tom. I forgot to mention that the module attached to the distributer is good and like you mentioned, if it was bad I wouldn't get a spark. I swear to zeus. IF and WHEN I get this running, I'm throwin' a freakin' party.Cool


Tom Greenleaf
Ultimate Carjunky / Moderator
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Aug 31, 2005, 2:29 PM

Post #4 of 12 (3650 views)
Re: 91 Crown Vic 5.0L won't start Sign In

One more thought - gas soaked spark plugs don't air dry all the time. They can be dried out if made glowing hot with a simple propane torch. What can happen is the white porcelain becomes a conducter and even with proper spark - WON'T make the needed jump. They can look fine and are NOT! That may not be the trouble but it's food for thought. Tom ---- Let me know about the party!Smile



harleyguy
User

Sep 1, 2005, 4:25 AM

Post #5 of 12 (3632 views)
Re: 91 Crown Vic 5.0L won't start Sign In

hmmmmm.......interesting...but I just put in brand new Bosch Platinum plugs and my experience with these plugs in the past is that they fire religiously. I've taken the same plugs out after 40K miles and they looked nearly good as new. I've taken one of the plugs out and cranked it. there is a visible blue spark so I'm still thinking fuel clog in the rail or injector. how do I test the injectors to see if they are working properly and how do I unclog the rail from the schrader to the injectors? there may have been some bad fuel with deposits that got passed through to the injectors before I purged the line.


Tom Greenleaf
Ultimate Carjunky / Moderator
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Sep 1, 2005, 8:11 AM

Post #6 of 12 (3627 views)
Re: 91 Crown Vic 5.0L won't start Sign In

You have good plugs - those are great.

Know that you have 8 fuel injectors and the chances of all failing is near nill. Is the available fuel pressure OK??.....



harleyguy
User

Sep 1, 2005, 9:27 AM

Post #7 of 12 (3624 views)
Re: 91 Crown Vic 5.0L won't start Sign In

Yea Tom. Fuel pressure is so strong at the schrader on the rail that I could shoot flies off the fender.Sly I'm not real strong on the workings of the EFI but I'm inclined to believe that shooting starting fluid in the intake would at least give me a sputter. Do the injectors fire in the same firing order? Maybe my firing order is off. It says 5.0L on the intake but this motor has been replaced. Apparently there are two 5.0L engines that ford developed. One was the 5.0L HO. how do you tell the difference between the two? one firing order is 1-3-7-2-6-5-4-8 and the other is 1-5-4-2-6-3-7-8. Even if the firing order was off, wouldn't the plugs still be soaked like it was carbureated?


Tom Greenleaf
Ultimate Carjunky / Moderator
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Sep 1, 2005, 2:47 PM

Post #8 of 12 (3619 views)
Re: 91 Crown Vic 5.0L won't start Sign In

I've never had to mess with firing order on a 5.0 in 10 million miles or more! The fact that it didn't even cough with some starter fluid kind of rules that out for now.

As for the HO - if the air cleaner is on the driver's side and the upper intake manifold has it's snorkle to the driver's side it's a regular 5.0. The HO IS all different but looks about the same. -- Like a mirror image and firing order is different! A Crown Vic was a popular Police car and could have and HO but I think most went to a 5.7 engine or what we know of as the 351. Stickers underhood should say exactly.



harleyguy
User

Sep 6, 2005, 4:50 AM

Post #9 of 12 (3599 views)
Re: 91 Crown Vic 5.0L won't start Sign In

Yes Tom. The snorkel and intake is just as you say. On the driver's side of the motor. This car was a police car called the "Interceptor". I'm not sure what mods they used for the interceptor series but I'm guessing a larger rad, dual exhaust and the performance chip. I am still leaning toward a fuel problem because the plugs fire. How can I make sure that the fuel is getting to the plugs from the fuel rail? I have good pressure at the schrader but I have dry plugs. Not likely that all eight injectors are failing simultaneously like you said. thanks for all of your help talking me through this. I am going to work on it more this evening and I will have more to tell you tomorrow.


Tom Greenleaf
Ultimate Carjunky / Moderator
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Sep 6, 2005, 8:24 AM

Post #10 of 12 (3593 views)
Re: 91 Crown Vic 5.0L won't start Sign In

Summary:

Engine has spark, fuel pressure (should make it over 40 psi) and won't even sputter with starting fluid?

Starter is slow.

Spark plugs are dry.

Car sat around a year or so. But was running then.
_____________________________________________________________

It was a long time ago but had a problem with old Buick - priciples are the same, with the lifters losing all pressure for a long time that wouldn't open the valves. The slow starter (don't go nuts cranking - 10 seconds then a cool down) could not be enough to to build up oil pressure the get them operational.

You could try spraying starter fluid directly into cylinder of the easier bank and or just four or five easy ones and replace. Give the thing a try - If it now sputters or even coughs that may be the problem! Check some carb or brake cleaner or whatever so you have for nozzes with the spray tube and give the cylinder a good shot without going too far. Go as fast as you can as the starter fluid will completely evaporate. Be ready with jumper cables on for the fastest spin you can give it.

Just something to try, -- I don't know a way to give the car full oil pressure with it off. A compression test would also indicate this was a possible problem.

I can't believe all eight fuel injector went bad, some kind of blockage maybe, but I think the test on the rail is the last stop before the injectors, Keep at it,



motorheadII
User

Sep 7, 2005, 12:28 AM

Post #11 of 12 (3585 views)
Re: 91 Crown Vic 5.0L won't start Sign In

Harley I don't know if you've already tried this, but you can disconnect the harness from one of the injectors and connect a 12v test light from one wire to the other to see if the injectors are actually being commanded on by the ECM. The light flashing on and off while cranking engine is normal. If there is also 30-40 psi fuel pressure, the problem is almost certainly in the injectors. Using a stethoscope, listen for decisive injector clicking while cranking the engine. If everything checks ok and the plugs are still dry, it may be necessary to remove the fuel rail and injectors for pintle cleaning. Get back to us on what you find.


harleyguy
User

Sep 7, 2005, 5:38 AM

Post #12 of 12 (3582 views)
post icon Re: 91 Crown Vic 5.0L won't start Sign In

Cool MY CREATION LIVES!!!!! Thanks to Tom and the rest of you guys for talking me through my problem. I have tracked it down and here is what I've found. I suspected some sort of fuel problem so I started concentrating on the rail and injectors. I pulled the connector on the #5 injector and connected a meter to it. With the ignition ON, I was measuring 40mv. In the START mode, the meter jumped to a paltry 70mv. Hmmmmmm.....Voltage but not nearly enough to trigger the injectors with any real consistency. I figured that I should be seeing at least a 10V pulse in the start condition. So now I'm thinking we got a high resistance connection and let's start at the source. The fuse block. On the fuse block is a 20A mini fuse that looked somewhat oxidized on the one blade. I put my meter across it while it was in circuit and I read 7.7V. Almost nearly open circuit voltage. So I pulled the fuse and took some sand paper, cleaned the fuse and checked it again for continuity. Now I had good continuity. I plugged it back in and crossed my fingers. After about 5 seconds of cranking it blew black smoke like the Chitty Chitty Bang Bang and came to life. Only problem now is either a seal or the oil pan gasket gave up the ghost because it spewed oil from behind the engine worse than Jed Clampets well on the Beverly Hillbillies. Now if I can keep it producing oil like that, I just may move to Beverly with the swimming pools......movie stars. Y'all come back now ya hear? Wink

Many thanks Tom and motorheadII.
Harleyguy






 
 
 






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