09-06-2000, 03:30 PM
I have a 1990 thunderbird SC I just got it about 2 weeks ago. Although there is a problem with it and I donít know what it is maybe you may know. This problem just happens about once or twice a day. Let me describe it to you, it kind of wants to turn off but it doesnít and while its doing this the rpmís keep on moving from 1 to Ĺ over and over again (LIKE IT WANTS TO TURN OFF, also jerks while doing this) and every time I step on the gas it does it more frequently with harder jerks. Another thing that also happens is the supercharger gauge moves like in intervals not steadily increasing it also struggles like the rpmís It usually goes away after about 2 to 4 min(SOMETIMES AFTER THE PROBLEM IS GONE THE RPM GAUGE WILL NOT WORK) or if I stop and turnoff the car and then start it up again the problem is gone but the rpm gauge doesnít work for a while (10-20 min.)- Sometimes the car will turnoff by it self out of know where just like the problem pops out of nowhere. The problem usually happens on the freeway and rarely on the street My speed gauge also doesnít work sometimes.
Some one told me to change the camshaft sensor and the crankshaft sensor? what do you suggest?

Some also told me to change the idle speed sensor what do you suggest?

Hopefully you can help me or refer me to someone that can. I live in LosAngles, Ca. Thank You Very Much For Your Help.

11-28-2000, 07:34 PM
I have a 90 SC too. My car did the same thing. What I found was my Crankshaft sensor was going bad along with my spark plugs. I changed my spark plugs but it didn't help. So I ended up changing the crankshaft sensor, the car worked fine after that.

04-10-2001, 10:12 PM
i would try check fuel pump or fuel filter


04-17-2001, 09:38 PM
I have an 89 SC, and shorly after I got it I had the exact same problem. I'm really not sure exactly what it is, but I figured it had to have something to do with the ignition system. I got that idea when I noticed the RPM gauge would quit on me, and the signal wire for the rpm gauge goes directly to the DIS. I had the dealer go ahead and change the entire ignition system for me, and I haven't had that problem since. That was about 4 years ago, so I figure I nailed it. Good luck.
'89 SC 5-speed
SCCoA Member #1448

SC SHOfanatic
04-18-2001, 12:09 AM
Do you know how to make it run the ignition-on, engine-off self test. If so, run it, clear the memory and do it again to see what codes come up.


'89 SC 5-speed

05-18-2001, 06:04 PM
I had the exact same problem with my 89 XR7. I learned how to run the test Chuck spoke of in the previous reply, and it revealed that it was the camshaft sensor. So for $30 at Autozone I picked one up, it was easy to install, and has been runn'in strong ever since. I hope your problem is as simple as mine.

89 XR7, 5 speed