1981 electronics

Reply Subscribe

Thread Tools

Search this Thread

Jan 9, 2016 | 02:34 PM

rolltidechris

Thread Starter

Cruising

Joined: Sep 2015

Posts: 10

Likes: 0

1981 electronics

Can someone please tell me what this is? Should this be plugged in?

Last edited by rolltidechris; Jan 9, 2016 at 02:35 PM. Reason: it is located in the battery box

Jan 9, 2016 | 02:44 PM

gjohnson

Drifting

Joined: Mar 2008

Posts: 1,808

Likes: 439

From: Denver CO

YES. That's the ECM.The cars brain.Unless the motors been changed out to a non computer car

Last edited by gjohnson; Jan 9, 2016 at 02:45 PM.

Jan 9, 2016 | 03:05 PM

rolltidechris

Thread Starter

Cruising

Joined: Sep 2015

Posts: 10

Likes: 0

Quote:

Originally Posted by gjohnson

YES. That's the ECM.The cars brain.Unless the motors been changed out to a non computer car

That makes sense, the original owner told me he was converting it over to the 1980 style carb and distributor. He had done the carb but not the distributor when I purchased it.

Jan 9, 2016 | 03:08 PM

454Luvr

Burning Brakes

Joined: Jul 2015

Posts: 823

Likes: 57

From: Austin TX

'81 had an ECM? I thought that was only used with TBIs. Weren't all the '81s carbureted?

Jan 9, 2016 | 03:16 PM

toobroketoretire

Melting Slicks

Joined: Apr 2009

Posts: 2,632

Likes: 112

From: Great Plains Iowa

Quote:

Originally Posted by 454Luvr

'81 had an ECM? I thought that was only used with TBIs. Weren't all the '81s carbureted?

Yes, but they were ECM controlled carburetors in which the idle circuit was controlled.

Jan 9, 2016 | 04:11 PM

7T1vette

Team Owner

Joined: Jan 2006

Posts: 37,637

Likes: 3,116

From: Crossville TN

If the engine no longer has the '81 "electronic" carb, you need to swap out the distributor for a standard GM points or HEI distributor, too. The original '81 dizzy has timing regulated by that [non-functional] ECM, also. As it is now, your ignition timing is at a 'default' level for start-up mode, only.

Jan 9, 2016 | 11:35 PM

64roadster

Burning Brakes

Joined: Aug 2003

Posts: 1,060

Likes: 19

From: Ocean Springs, MS

St. Jude Donor '07

Quote:

Originally Posted by rolltidechris

Can someone please tell me what this is? Should this be plugged in?

Yep, ECM. I have an '81 project that did not run when I bought it so I've been thru this system quite a bit. I almost opted for the non-ECM carb a number of times but decided to stick with it and learn more about it. Now I finally have it running correctly. If you stay with the E4ME carb I would suggest getting a scanner to help you decipher what the ECM is telling you.

I understand that removing the ECM also requires changing intake manifold, carburetor, and distributor. I priced that change at about $1,000. But the challenge of understanding the E4ME was worth it.

BTW, getting a replacement ECM runs about $100. Finding a good Prom for an automatic is not easy.

Last edited by 64roadster; Jan 9, 2016 at 11:37 PM. Reason: Adding info