Code h36 on 94 vette, need help please...
Thread Starter
Cruising
Joined: Jul 2006
Posts: 12
Likes: 0
From: Oswego IL
Code h36 on 94 vette, need help please...
This is my 1st post, I bought my husband a 94 vette for his 40th bday about a month ago. The other day I was driving it and decided to punch it to see what it could do, and as soon as I did, the engine sputtered/misfired, then my a/c turned hot (hot air was coming out), and the check engine light came on. The car continued to run (unlike some of the other postings I have read with the code 36). When I got home a few minutes later I turned the car off, restarted it, and the a/c began working again and the check engine light went off.. The only idea I have is the MAF, which is what I continue to see on this forum. Any ideas/suggestions are welcomed! Thank you for your help!
Thread Starter
Cruising
Joined: Jul 2006
Posts: 12
Likes: 0
From: Oswego IL
what is the opti and where is it located?
WOW!! Thanks for the quick reply! You rock!! Can you please elaborate? What is the opti and where is it located? Also, if we don't fix this, can we just continue to drive it like old folks and not punch it and not hurt anything?? Thanks again!!! 
Le Mans Master
Joined: Mar 2004
Posts: 8,700
Likes: 298
From: Ft. Lauderdale Fl
Originally Posted by thefixmom
WOW!! Thanks for the quick reply! You rock!! Can you please elaborate? What is the opti and where is it located? Also, if we don't fix this, can we just continue to drive it like old folks and not punch it and not hurt anything?? Thanks again!!!
---The Opti is located under your water pump. Its in the front of your engine, all the way down, you can't even see it. The second question, "can we continue to drive it like old folks", No, the problem just gets worse and worse until starting the engine becomes impossible.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
the Optispark is the distributor. It has two main parts, the high voltage (cap/rotor/coil) or "spark" and the optical sensor, the "Opti" part.
The optical part keeps track of engine timing and fuel injection timing. That's where the error comes in. The code 36 means that it can't keep track of engine timing correctly (high resolution). The other code you could get is a code 16, which is a low resolution error, meaning it can't keep track of the fuel delivery.
What would cause this? Failing electronics, or, a bad bearing inside the optispark causing the optical disc to fall out of aim with the light sensor.
either way, a new Optispark is in order. I suggest getting an MSD unit.
The optical part keeps track of engine timing and fuel injection timing. That's where the error comes in. The code 36 means that it can't keep track of engine timing correctly (high resolution). The other code you could get is a code 16, which is a low resolution error, meaning it can't keep track of the fuel delivery.
What would cause this? Failing electronics, or, a bad bearing inside the optispark causing the optical disc to fall out of aim with the light sensor.
either way, a new Optispark is in order. I suggest getting an MSD unit.
Le Mans Master
Joined: May 2005
Posts: 7,354
Likes: 2,278
From: Central Maryland
Welcome to the 'hood, and congrats on the new toy!
Sorry to hear you're gonna have to replace the Opti so soon. I know how that feels. I had my '94 for two weeks when the Opti failed, so I learned a lot about Optis real quick.
Suggest you check out these recent threads for more info:
http://forums.corvetteforum.com/show....php?t=1450906
http://forums.corvetteforum.com/show....php?t=1454837
Be well,
SJW
Sorry to hear you're gonna have to replace the Opti so soon. I know how that feels. I had my '94 for two weeks when the Opti failed, so I learned a lot about Optis real quick.
Suggest you check out these recent threads for more info:
http://forums.corvetteforum.com/show....php?t=1450906
http://forums.corvetteforum.com/show....php?t=1454837
Be well,
SJW
Thread Starter
Cruising
Joined: Jul 2006
Posts: 12
Likes: 0
From: Oswego IL
You guys (I assume?) are AWESOME!!!
I'm just sad it's gonna cost bet. 1500-2k by the sound of it. We are taking it to the dealer we purchased it from, Corvette Collection. Any word on them? They said they would work w/us, we're past the 30 day (of course) 50/50 repair warranty they offer, but said they'd work w/us. I'm keeping my fingers crossed that they really are good guys like you all (this is WAYYYYYYYYYYYY better than I could have imagined a web forum could be!! - usually people just do stuff that doesn't matter or help anyone for real)...
Anywho, happy drivin' to ya'll and I'll let you know what happens. I can see now why you can fall in love with a car! Never understood it until I drove it. Vettes are da bomb!!! Peace out!
Anywho, happy drivin' to ya'll and I'll let you know what happens. I can see now why you can fall in love with a car! Never understood it until I drove it. Vettes are da bomb!!! Peace out!
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
damn... I hate dealers.
I hope they suck it up.
Whatever you do, do NOT replace that optispark with OEM. I have read here where several members have had problems with Delco optis... throwing codes and such.
I would advise getting an MSD part.
If you or the hubby are handy with hand tools, this is a DIY project... just take your time.
I would consider replacing the waterpump.
I hope they suck it up.
Whatever you do, do NOT replace that optispark with OEM. I have read here where several members have had problems with Delco optis... throwing codes and such.
I would advise getting an MSD part.
If you or the hubby are handy with hand tools, this is a DIY project... just take your time.
I would consider replacing the waterpump.
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Safety Car
Joined: Apr 2003
Posts: 3,793
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From: VA
Originally Posted by thefixmom
This is my 1st post, I bought my husband a 94 vette for his 40th bday about a month ago. The other day I was driving it and decided to punch it to see what it could do, and as soon as I did, the engine sputtered/misfired, then my a/c turned hot (hot air was coming out), and the check engine light came on. The car continued to run (unlike some of the other postings I have read with the code 36). When I got home a few minutes later I turned the car off, restarted it, and the a/c began working again and the check engine light went off.. The only idea I have is the MAF, which is what I continue to see on this forum. Any ideas/suggestions are welcomed! Thank you for your help!
To find a competent mechanic you should post in the appropriate regional section of this forum and see if anyone can recommend a mechanic in your area.
The reason given above for avoiding an OEM optispark is poor advice. There are reasons to choose an aftermarket opti, but problems with new OEM optis is not one of them. There are probably over 100,000 OEM replacement optis on the road with no problem. We've heard about a handful of problems on here, and most if not all of those were installed by DIYers.
Once you find that competent mechanic, if it does turn out to be the optispark, talk to him about the replacement options.
Le Mans Master
Joined: May 2005
Posts: 7,354
Likes: 2,278
From: Central Maryland
Originally Posted by Vis Croceus
All of the symptoms you describe are not explained by a failing optispark. You need to get a real diagnosis - not an internet diagnosis or a diagnosis by the place that sold you the car - before you spend money on repairs.
The reason given above for avoiding an OEM optispark is poor advice. There are reasons to choose an aftermarket opti, but problems with new OEM optis is not one of them. There are probably over 100,000 OEM replacement optis on the road with no problem. We've heard about a handful of problems on here, and most if not all of those were installed by DIYers.
The reason given above for avoiding an OEM optispark is poor advice. There are reasons to choose an aftermarket opti, but problems with new OEM optis is not one of them. There are probably over 100,000 OEM replacement optis on the road with no problem. We've heard about a handful of problems on here, and most if not all of those were installed by DIYers.
1. I may be mis-remembering this, but I think the ECM will shut off the A/C when certain DTCs appear. If this is true, I think the symptoms are consistent with a dying Opti. A Code 36 is almost surely either a dying Opti, a failed input line on the ECM, or a wiring harness fault between the Opti and ECM (and in nearly all cases it turns out to be the Opti).
2. I think the advice to avoid an OEM replacement Opti is sound. The replacement first-generation OEM unit is no different from the unit that was installed at the factory, which by GM's own admission (implicit by their major redesign of the Opti) is widely accepted to be highly deficient. With the DynaSpark and MSD units available as bolt-on replacements, I cannot in good conscience advise anyone to install another OEM piece as a replacement, unless it is a desperate situation that doesn't permit other options.
Be well,
SJW
