1A2 Tach and Oil Pressure problem

Hello Everyone,
I read a few threads regarding tach issues. I have a 1991 1A2 that I finally got on the road today after it sat for nearly 8 years. The Tach idles at 15 and gets buried when you step on the gas. Im guessing from the threads that it is the board on the back of the cluster. Mine has the 1A2 Certified digital speedometer. I was wondering if anyone had done this type before. I imagine its very similar as described in the other threads. Also, The oil pressure gause gets buried too. Possibly the same bad cluster?
Finally, Will a CC RM or analog Caprice board work on the back of a Digital Cluster or are they different.
Thanks for the help, You may be hearing more from me as I get the kinks out.
Nick in PA

My 91 OCC did the same thing with the tach and oil pressure gauge as yours.The oil pressure gauge being pegged is due to the sensor on the engine going bad.My tach started reading twice as fast after a tune up due to the wrong ignition module being installed.I swapped back in the original module recently which cured the tach problem completely.The oil pressure sensor is about 50 bucks from GM,I still have the part number somewhere but have to look for it.Both are easy fixes.

Thanks,
Ill have to try the oil pressure sensor. I put one on my custom cruiser many years ago and I remember it being real easy.
Ill look up the ignition module too.
Have a good day,
Nick

If it is not the ignition module, the boards are different. If the cluster is the same as an 91-3 9C1, there is one in a local yard for the next 3 weeks.

Sending unit is like $30 or so on RockAuto. Just make sure you're ordering a sending unit for the gauge, not a switch for the idiot light.

I love that cluster - best mod I ever did for my '92 Civi wagon.

FOUND IT,the delco number for the oil pressure gauge sensor is 10222130.

it is the 91-93 9C1 cluster, digital speedo, analog tach. Fred I would grab it anyway, not many around anymore. I buy every one I see (think I have 3 now).

Thanks for the part number,
I believe it is the same cluster. I priced the oil pressure sensor at Autozone today, It is $33. The ignition module is $44.
Ill try them when I get some extra cash to play around with. The car is just a toy and not a daily driver. I just put $90 battery in it yesterday. When your a married guy, you need to ease these expenses into the budget. Ill have to grab a cluster when I see one at a junkyard just to have in the future. I think the LTZ had the digital speedometer too but It wouldnt say certified for the 1a2. It may be the same board though.
Thanks ,
Nick

Yes, it's the same board. The only difference is that it doesn't say "CERTIFIED" like a 9C1/1A2.

The LTZ actually says certified too. At least on some years. As my parts cluster came from a '92 LTZ and it says certified.