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unisonicz
04-18-2017, 11:50 PM
Hello everyone, my recently purchased 89SC dies randomly and I am not able to reproduce it, just completely random. Symptoms are the up arrow light goes solid, rpms drop instantly and car dies. Sometimes it will start right back up and drive fine. Sometimes it will start right up and drive for a few feet then die again, other times it will crank no start for a few to 10 minutes. Temps and oil pressure are fine. From what I have been reading is it is most likely harmonic balancer and or crankshaft position sensor and a small chance of it being the cam shaft position sensor. Now another thing that may be adding to my issues is my ignition on the steering column is very touchy/going bad. Now my question is, from what I have explained here where should I start first?

Thanks
Tad

KMT
04-19-2017, 12:17 AM
You should replace the multi-wire ign. switch in any case, but I'd check the balancer first, to be sure it isn't ready to fail/come loose/cause trauma - repair as needed if it has seen better days, broken bolts, etc. If it's solid, run the codes, then see if you need to go after the crank/cam sensors. Don't forget to inspect the front harness for abuse, etc.

Tim Groth
04-19-2017, 09:38 AM
From what you described sounds like the Crank bolt may have sheered off - Stick your finger inside the pulley and see if you have a bolt holding it onto the crank. Have had this happen a few times in my ownership of several SC's and it sounds just like you describe.

-Tim

unisonicz
04-19-2017, 11:35 AM
My apologies, I forgot to mention what I have checked. Visual inspection of the harmonic balancer and the crank aensor. The balancer "looks" OK and does not wobble while the car is running and does not move when I pry on it a little bit. Also the crank bolt is present and tight. The sensor "looks" good and is not damaged or loose. I have checked all electrical connections and pulled plug wires one at a time while running. When each plug is pulled the the rpm changes slightly and all are getting very good spark.

I will be changing the ignition tonight since it needs to be done regardless.

Thanks for the input everyone.
Tad

HwyStar
04-19-2017, 11:45 AM
Did you check your ignition control module? If it has too much, or no contact grease at all? You will not transfer enough heat and it will quit on you. If you have a aftermarket ICM, they do work fine. But, what I have found with those, is that they typically are concaved on the side that should be conducting heat. What I do with those is plane the bottom with a rough file till I get it relatively flat. That way I can get the most contact and heat transfer. Might be worth looking at.

KMT
04-19-2017, 11:56 AM
That way I can get the most contact and heat transfer.

Thermal images show the module runs cooler than the pedestal. Heat rises and is transferred up from the module, into the airflow thru the nose of the car and back over the engine, then down. You don't want to encourage more heat coming up from the pedestal ;)

What you do want to encourage is a good ground path thru the pedestal. That occurs thru the small mounting bolts on at least two of the corners on the module, so be sure those are clean and not loose.

unisonicz
04-19-2017, 08:24 PM
Thanks everyone for the input so far. I have a new ignition switch I am going to install tonight and check grounds and go from there. I will update this thread as I go along. Also, does anyone have a link for a good all around good post for checking codes on these cars?

Thanks again
Tad

KMT
04-19-2017, 09:28 PM
Also, does anyone have a link for a good all around good post for checking codes on these cars?


Do you have a code reader for your year SC yet?

A code list that is also SC-specific is here:
http://www.njtacc.com/tech/eec_codes.html

unisonicz
04-19-2017, 09:54 PM
Okay so update. Replaced ignition on the column. Very easy to do. It died again within minutes. Got underneath the car to look things over again.... didn't see anything out of place. Decided to have the girl friend crank it over and the balancer no longer rotates square/evenly. It wobbles. So, going to be replacing that this weekend. Any tips and tricks that you guys have found that will make this job easier/less of a headache?

Thanks,
Tad

TSC89
04-20-2017, 12:02 AM
Stay away from the Dorman harmonic balancer that is "supposed" to be for the SC.

Best options are the Power Bond by Dayco or the BHJ.

http://www.oreillyauto.com/site/c/detail/PPI0/PB1530N/02316.oap?year=1991&make=Ford&model=Thunderbird&vi=1140433&ck=Search_02316_1140433_-1&pt=02316&ppt=C0332#compatibilityTab_

unisonicz
04-20-2017, 09:30 AM
I have the powerbond coming in from orielly's. From what I have been reading is the balancer bolt is a one time use and oreilly's can not get them. Does anyone have the bolt size length thread/pitch so I can go get a grade 8 from my local fastener place?

potshotscott
04-20-2017, 12:18 PM
I don't have the size but if you strike out at your fastener shop bill at supercoupeperformance has what you need. https://www.supercoupeperformance.com/harmonic-balancer-bolt-and-washerextra-long-design-77

TbirdSCFan
04-20-2017, 05:37 PM
I have the powerbond coming in from orielly's. From what I have been reading is the balancer bolt is a one time use and oreilly's can not get them. Does anyone have the bolt size length thread/pitch so I can go get a grade 8 from my local fastener place? Thats what I did.. :D and its still holding up. Granted I don't drive the car all that much. I don't know about the bolt being a single use, but because the balancer can have wear, they don't advise putting it back on. However, like most all things, your mileage may vary... I've gotten away with reusing a balancer with little internal wear. OTOH, I tend to inspect the engine+balancer rather frequently just in case something breaks.

unisonicz
04-21-2017, 02:13 PM
Another update. Apparently the balancer comes off a lot easier if you take the washer out. I got the bolt out no problem but I guess the washer was kinda stuck in there. Broke a balancer remover lol. Once I figured out the washer was in there, took it out and it came off easy with the removal tool... oh well, live and learn. Upon inspecting the balancer there is play in it. Will install the new one tomorrow and then test drive the car.

rickbtbird
04-21-2017, 02:59 PM
Hello everyone, my recently purchased 89SC dies randomly and I am not able to reproduce it, just completely random. Symptoms are the up arrow light goes solid, rpms drop instantly and car dies. Sometimes it will start right back up and drive fine. Sometimes it will start right up and drive for a few feet then die again, other times it will crank no start for a few to 10 minutes. Temps and oil pressure are fine. From what I have been reading is it is most likely harmonic balancer and or crankshaft position sensor and a small chance of it being the cam shaft position sensor. Now another thing that may be adding to my issues is my ignition on the steering column is very touchy/going bad. Now my question is, from what I have explained here where should I start first?

Thanks
Tad

good luck!

unisonicz
04-29-2017, 11:48 AM
Alright, finally got the new harmonic balancer installed. Was not hard but I just had to find the time to do it. Still dies randomly with the same symptoms. Going to play with the adjustment on the crank shaft position sensor and see if that helps.

sam jones
04-30-2017, 01:35 AM
Good evening



Before running the engine and making adjustments to the camshaft sensor and synchronizer check the following:


Check the for # 1 cylinder and the harmonic balancer is pointing to the correct 26 0 ATDC compression mark.

Check the camshaft sensor electrical connector is position properly not forward of the supercharger belt. If either is your problem is problem correct and repeat the camshaft sensor and synchronizer installation procedure which is addressed in the SCCoA forum, Haynes and Chilton repair manual.


Have you checked operating fuel pressure? Is there any evidence of fuel pressure regulator leaking? Have you recovered any codes yet? Have you cleaned the MAF sensor?


Good Luck.

unisonicz
04-30-2017, 11:33 AM
The MAF has been cleaned, it was the first thing I did. I suppose I can pull it and clean it again. I will read up and check the camshaft position sensor and and check the timing. I have not checked the fuel pressure yet. The car runs better with the new harmonic balancer and starts right back up with no issue and it runs longer. I will check the things listed here.

Thanks Sam