Alarm at start. Tack doesn't go over 1500 although engine does.
 

hey everybody, i've got an '88 2nd gen. non-turbo convertible... it's been running pretty good, recently had to replace the fuel pump. i keep the oil changed as well as good plugs in it... this morning when i got in to go to work, i started the car and noticed a buzzer alarm going off. the alarm is a steady buzz, similar to the one that goes off when low on coolant. i checked my coolant, and oil. both are good. the car was running fine as of last night, went to arkansas and back (2.5 hr drive one way), and everything was running fine... along with the annoying alarm, i noticed that the tach. isn't reporting properly... it stays below 1500 rpm's and i know i'm going much faster. the engine mechanically sounds good. as i was merging on the interstate i was giving it some throttle and noticed that the steady alarm became a "gurgling" alarm. i looked at my tack and noticed that the needle was dropping repeatedly in sync with the gurgle; but my engine itself was properly accelerating and sounded fine. i consulted my Haynes manual, to find nothing on this topic. could somebody please give me some pointers to check out, or even better, can somebody tell me what's wrong with my car?

thanks

Cold weather problem?
 

just as quickly as the problem started, it went away. when i was going to lunch, i started my car, and everything just worked properly. It may have something to do with it having been 25 degrees this morning, or maybe not... i don't know enough about my car to say for sure. but if anybody out there has anymore ideas about this, i would love to know them just in case it does this again. your help is greatly appreciated.

thanks

Probably a bad trailing coil or ECU

on second thought
 

i was discussing the problems with a co-worker; and the rev limiter was brought up. after some thought, the problem that it was giving me this morning was more like the car is supposed to act when going about 7 - 8 thousand rpm (with the buzzer, and the tack jumping down when accelerating, and not reporting over 1500 rpm.). Is there some type of sensor or cable that governs what the tack reports and could maybe falsely report something like a 1500 rpm red line? this morning when it was acting up, everything was still running properly, and it still hauled ass down then interstate. :P

The tach gets it's signal from the trailing coil.

Yes there is a circuit board in the tach that has a pot that is adjustable for the redline buzzer, but it reads off the tach signal, so if the tach was reporting 1500, the signal from the trailing coils was 1500.

It did it again.
 

As previously stated, the problem went away yesterday. Everything seemed to work fine for the rest of the day. This morning, when i got in my car (off to work again), the alarm kicked on making that awful buzzing sound and the tach was doing that same thing again. The only difference was this time, it stopped right before i got to work. I looked at the temp gauge, and it was a bit warmer than usual (in relation to the cooler weather, but it wasn't freezing cold or anything like that last night), as soon as the buzzing stopped the temp dropped. The higher temp that it was registering this morning wasn't a high temp, like i would get from a sticking thermostat. I also noticed this morning that when the buzzer starts, it starts before i start the car, as soon as i turn the key to the "on" position. Is this still going to be the trailing coil? I'm a network tech, and i'm learning automotive as i have to fix this car. lol