Code 36 Fault Issue & Rough Idle - ZR-1 Net Registry Forums

pattonas · 03-22-2022

Looking for some guidance. I have a 90 ZR1 1 with 27K miles on it. I jut installed a Billy Boat cat back x-pipe exhaust. Soon after it started idling rough. Service light came on too and I checked for codes and it shows a #36 which I believe is something to do with the ignition/ECM. Car starts just idles poor.

Thanks Scott

WARP TEN · 03-22-2022

Is it possible that during the installation the O2 sensors or wires got damaged? Or maybe they are original and were just waiting for an excuse to fail? That could cause some poor running.--Bob

richarde · 03-23-2022

It's hard to see a link between fitting a BB cat back exhaust and a code 36. The 1990 Corvette Service Manual has a good diagnostic check for a code 36 on page 6E3-A-56 and 57.

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tf95ZR1 · 03-24-2022

Per Dynomite's Sticky:

Code #36: Direct Ignition System (DIS) Circuit (missing or extra EST signal)

viper107 · 03-24-2022

i know one thing,the ecm,s were junk in them years, i would update it to the improved part number , 95 zr-1 ecm in any 92 down z

ZR1CK · 03-31-2022

I had a similar experience with code 36 and 31. 31 being a cam sensor issue. The car started real hard, ran extremely rough, would then all of a sudden run okay and then run rough again and almost stall out, and did a couple of times. I'm not gonna go into details as to what I did to try and chase down the problem, it'll take too long. If you have or can get ahold of the shop manual for that year, follow the diagnostic procedures for that code as mentioned by richarde above. My problem ended up being the ECM. I tried a whole lot of other things before I went to the ECM, hoping it wasn't the issue, but finally decided to send it out to Marc Haibeck to have him check it out. He refurbed it and sent it back and the car now runs great again. By the way, I have a '91 with around 27k miles. Good luck.

03-22-2022	#1
pattonas Join Date: Feb 2022 Location: Woodstock, GA Posts: 3	Code 36 Fault Issue & Rough Idle Looking for some guidance. I have a 90 ZR1 1 with 27K miles on it. I jut installed a Billy Boat cat back x-pipe exhaust. Soon after it started idling rough. Service light came on too and I checked for codes and it shows a #36 which I believe is something to do with the ignition/ECM. Car starts just idles poor. Thanks Scott

03-22-2022	#2
WARP TEN Join Date: Apr 2007 Location: Lake Bluff, IL Posts: 2,120	Re: Code 36 Fault Issue & Rough Idle Is it possible that during the installation the O2 sensors or wires got damaged? Or maybe they are original and were just waiting for an excuse to fail? That could cause some poor running.--Bob __________________ 2016 Long Beach Red Z06 #10281 "POPS Z" 1995 Polo Green #409 "WARP TEN"--Haibeck 350/510 package, 4.10s, Hurst, Stock Exhaust with QTP Cutouts --Sold but still running strong 1993 Quasar Blue #161 "HIL KING" --Sold but still running strong, now with more than 120,000 miles 1967 Marlboro Maroon/Saddle Corvette Coupe 300 hp/4-spd --Sold a long time ago ZR-1 Net Registry Founding Member #95 NCM Lifetime Member Favorite Quote--Attributed to Mickey Thompson: "Too Much Horsepower is Almost Enough" Last edited by WARP TEN; 03-22-2022 at 11:40 AM.

03-24-2022	#4
tf95ZR1 Join Date: Aug 2005 Location: Northridge, CA Posts: 1,461	Re: Code 36 Fault Issue & Rough Idle Per Dynomite's Sticky: Code #36: Direct Ignition System (DIS) Circuit (missing or extra EST signal) __________________ 1995 ZR-1 #106 Blk/ Blk Owned by me since 2000. 93K miles, but not on motor :-) Mods the way I want it, Not afraid to drive it!

03-24-2022	#5
viper107 Join Date: Dec 2019 Location: st louis mo Posts: 742	Re: Code 36 Fault Issue & Rough Idle i know one thing,the ecm,s were junk in them years, i would update it to the improved part number , 95 zr-1 ecm in any 92 down z __________________ 95 admiral blue z(sold)/ / 93 ruby z(sold) 91 steel blue z/95 aqua z haibeck 510, 91 callaway 415 areobody #5

03-31-2022	#6
ZR1CK Join Date: Jan 2013 Location: Liverpool, NY Posts: 35	Re: Code 36 Fault Issue & Rough Idle I had a similar experience with code 36 and 31. 31 being a cam sensor issue. The car started real hard, ran extremely rough, would then all of a sudden run okay and then run rough again and almost stall out, and did a couple of times. I'm not gonna go into details as to what I did to try and chase down the problem, it'll take too long. If you have or can get ahold of the shop manual for that year, follow the diagnostic procedures for that code as mentioned by richarde above. My problem ended up being the ECM. I tried a whole lot of other things before I went to the ECM, hoping it wasn't the issue, but finally decided to send it out to Marc Haibeck to have him check it out. He refurbed it and sent it back and the car now runs great again. By the way, I have a '91 with around 27k miles. Good luck.

03-23-2022	#3
richarde Join Date: Sep 2012 Location: United Kingdom Posts: 68	Re: Code 36 Fault Issue & Rough Idle It's hard to see a link between fitting a BB cat back exhaust and a code 36. The 1990 Corvette Service Manual has a good diagnostic check for a code 36 on page 6E3-A-56 and 57. Sent from my iPad using ZR-1 Net Registry __________________ Richard 1990, numbers 1821 and 2391 1821 - owned since Nov 2002, charcoal / Gray, Stainless headers, B&B system, 4.10's 2391 - owned since Jan 2019, Black / Black, have completed restoration. Jeal headers, Corsa system, 4.10's, Aluminum flywheel with Carolina clutch.