Error code 31 help

[Bcam]

Hello from Australia!

We've recently imported a 1990 torch red ZR1 and absolutely love it!

Recently the SES light has been coming on intermittently and we're getting an error 31 code.

The car still seems to run well with the only symptoms I'm noticing from the engine is that the oil pressure reads low and the revs seem to dip intermittently when at idle after the engine oil has heated up.

After a long drive yesterday, over an hour, the SES light illuminated towards the end of the drive. When trying to restart the car the engine had problems restarting. It would crank, give a little shake but wouldn't turn over. I only tried this once. This morning the car started fine like usual and no SES light.

I'm not a mechanic by a long stretch but I am mechanically minded and can fix most things, so any suggestions that may help would be great.

Thanks guys,

BC

[conesare2seconds]

Hi and welcome to the forum. Folks will check in with suggestions soon, I?m sure.

[Ccmano]

Welcome to the addiction... code 31 is the cam sensor circuit. More often than not it's the weatherpack connectors that are dirty either right at the sensor or the main connector to the ecm. Check the connectors, clean and reseat them with some Dielectric grease. If you don't have one already get yourself the Factory Service Manual. It will help you diagnose any of the code issues (any everything else). While it could be a bad cam sensor, do the diagnostics and cleaning first. Cam sensors not easy to get, although one of our members actually makes new ones on request (last I looked). And remember, the beauty of these forums (as opposed the Facebook) is that there is a search function for each section. You can search and read up on what was previously said and on any conceivable issue. On top of that there is the "Solutions" sticky at the top of the Technical Section, where member Dynomite has collated the answers to all known ZR-1/LT5 issues making them easy to find.
Check out this thread...
https://www.zr1.net/forum/showthread.php?t=32278&page=2

Good luck and keep us posted. Btw also attached for you is code 31 section of the 1990 manual.
H

[G8nightman]

Like the others said above also see if the cam sensor is leaking oil it might be cracked. Also if your car is a 90 the correct color is bright red. Torch red was offers I believe in 94 and 95.

[Erik]

Originally Posted by G8nightman

Like the others said above also see if the cam sensor is leaking oil it might be cracked. Also if your car is a 90 the correct color is bright red. Torch red was offers I believe in 94 and 95.

Definitely Bright Red. Much richer, deeper colour then the somewhat washed out, more orange, Torch Red. Not that I'm biased or anything.

[Mystic ZR-1]

Bright Red?
Pretty clever bunch of guys in the
GM Color Studio to come up with that name.....
One thing they did know, the red
one's are the fastest!!! 😀