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Discussion Starter #1 (Edited)
Hello:
Have a '97 Thunderbird with a 4.6l V8 that just wouldn't start the other day. We tried and tried. It was at a friends house and took me a couple days to get to it with my fuel pressure gauge and my spark tester. In the meantime, my friend assured me it wasn't starting as she tried a number of times.
Well, guess what, I get there yesterday and it fires right up. I hate chasing intermittent problems, but feel there is a wealth of experience here to guide me. Does this sound familiar to anyone?
Thanks for the help
Ty
 

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Discussion Starter #3
Oh Man - that is important v8

It is a 4.6 liter V8. That is important....is there a crank and a cam shaft position sensor?
 

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Yes there are both, but the cam position sensor won't prevent the car from starting. It is a very common problem for the wires to the crank position sensor to lose their insulation and touch, which will result in this no-start condition. Start by checking that. This is sensor is on the bottom passenger side of the engine going into the side of the timing cover, right by the A/C compressor.
 

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Yes there are both, but the cam position sensor won't prevent the car from starting. It is a very common problem for the wires to the crank position sensor to lose their insulation and touch, which will result in this no-start condition. Start by checking that. This is sensor is on the bottom passenger side of the engine going into the side of the timing cover, right by the A/C compressor.
I thought that the cam position sensor was used ONLY during starting to let the ECM know when #1 cylinder is at TDC on compression stroke, not exhaust stroke?
 

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I thought that the cam position sensor was used ONLY during starting to let the ECM know when #1 cylinder is at TDC on compression stroke, not exhaust stroke?
It is, but like I said it won't prevent it from starting. The PCM will assume that #1 is on the intake stroke. If it doesn't fire, it knows it guessed wrong and switches.
 

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I have been chasing this problem for years in my 97 T Bird and after changing every part I could think of, I finally decided to scrap it. I have another, so it will become a parts car for the other one. Hope you have better luck than I did. After spending over $1K, I gave up. I even sent it to a Ford tuner and after three weeks of scope testing, he even gave up. Replaced CPS 3 times, complete engine harness, main ECC, ECC power boards in front, right corner, cam pos sensor, IAC, MAF. Still intermittent fuel and spark. My tuner said maybe the wheel that signals the Crank Position sensor on the crankshaft is bent or loose. Time to scrap. Just not worth it.
 

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Discussion Starter #9
Godam, Bluebird.....thanks for the happy Monday note. I hope I have better luck than that. Of course, it is probably worth more as a parts car......hmmm.
 

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Godam, Bluebird.....thanks for the happy Monday note. I hope I have better luck than that. Of course, it is probably worth more as a parts car......hmmm.
Yes, I think you are right. I found one up in L.A. for $400. They have not held their value but make good transportation cars when running right. These T Birds seem to be beyond the point of $$$ after about 150K miles. Then all hell breaks loose. That's time to dump them and move on. Looking at new Challengers. No more Fords.

Phil
 

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The crank sensor is replaced. Gonna have to drive it a bit to see if that fixes it...stay tuned.
Ty, what is the verdict? Did the crank position sensor do the trick? I decided to open up the front of my motor and change the CPS signal wheel next. Might as well, I have tried everything else. Ignition is totally dead now, hot or cold. Good fuel pressure but zero spark. That is about all that's left. If it doesn't fix it, maybe I will do the DOHC engine swap.

Thanks, Phil
 

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Discussion Starter #14
Phil:
I have been driving it all week - not a problem so far. It has been hot and cold here, and it seems fine. I am concerned, since this is a demon, that it is still there lingering about, but I am getting more and more comfortable with it.
I have an idea for you - instead of the whole engine swap (and I think the DOHC engine is the same) how about grabbing a complete harness and computer from the junk yard and trying that first? Although, the bird would certainly love that new engine......
Good luck
 

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Ty,

IT'S FIXED!!!!! :cool::tongue: My problem turned out to be the EEC. Changed it again and it's starting perfectly. Whoever said the computers don't go out very often was dead wrong. I went through two bad ones before I got a good one. The trick was to get an EEC that is dated the same or slightly later than your original one. That's what made the difference. I thought about it long and hard and came to the conclusion that this is the only thing that can cause almost no startiing but very good running. You see all those sensors and wires would cause running problems too which I did not have. It had to be the computer and it was!!

Hope your stays fixed!! Phil
 

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Ty,

IT'S FIXED!!!!! :cool::tongue: My problem turned out to be the EEC. Changed it again and it's starting perfectly. Whoever said the computers don't go out very often was dead wrong. I went through two bad ones before I got a good one. The trick was to get an EEC that is dated the same or slightly later than your original one. That's what made the difference. I thought about it long and hard and came to the conclusion that this is the only thing that can cause almost no startiing but very good running. You see all those sensors and wires would cause running problems too which I did not have. It had to be the computer and it was!!

Hope your stays fixed!! Phil
I feel you on the bad computers deal. I'm on my third in my 'Bird, but what struck me funny is your "trick". The computer I put in my car has a date 10 months older than the one I pulled out and has a totally different catch code! The only difference I've noticed is it shifts a lot softer with this different EEC (even on downshifts).
 

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I feel you on the bad computers deal. I'm on my third in my 'Bird, but what struck me funny is your "trick". The computer I put in my car has a date 10 months older than the one I pulled out and has a totally different catch code! The only difference I've noticed is it shifts a lot softer with this different EEC (even on downshifts).[/QUOTE

I think I am going to buy all the later 97 T Bird 4.6L computers I can find at the junkyard. Down the road when the source dries up at the junkyards, you will be glad you put a few away. Apparently they do go bad fairly often. I have read that other people have had problems with these 97 EECs too. Mine had all the same codes and part number suffix, etc. but a slightly later production date.

Phil
 

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I think I am going to buy all the later 97 T Bird 4.6L computers I can find at the junkyard. Down the road when the source dries up at the junkyards, you will be glad you put a few away. Apparently they do go bad fairly often. I have read that other people have had problems with these 97 EECs too. Mine had all the same codes and part number suffix, etc. but a slightly later production date.

Phil
don't kill yourself looking for all those mn12 EEC's.....the 96/97 mustang gt auto pcm's are a direct swap so long as you use the 80mm mustang maf meter w/ housing....the tunes are not identical, but the base strategy is the same, thus the reason they can be swapped....other mustang gt auto pcms can be used as well, but those need to be adapted
 
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