82 timing issue
Thread Starter
Racer
Joined: Sep 2005
Posts: 359
Likes: 0
From: Shoemakersville Pa
82 timing issue
Helping a buddy here with the crossfire injection. Tried to set timing on his car last evening. Disconnected the ecm wire (tan color?) he did'nt have the quick disconnect so we jumped the other 2 wires from this plug (pink & lt. blue). The timing is jumping at least 3 deg. back and forth on either side of the 9 deg. I was trying to acheive. Reconnected the ecm plug same thing and really idling rough. Help Please!
Burning Brakes
Joined: Jan 2006
Posts: 1,154
Likes: 1
From: St Augustine FL
Ok this is fun stuff here. Tunning tha 82 can ba a PIA but once you get it down its easy. I know I have done it myself. The timing should hold steady. You might have a worn out timing chain or something. Since the computer controls the car then the timing could jump around if the computer is telling it to. Check out this link:
http://www.corvettefever.com/techart...ing/index.html
Read it several times. If there are vaccum leaks, they will reak havac on the idling and performance of the car. The vaccum leaks will cause the computor to do some screwing things.
http://www.corvettefever.com/techart...ing/index.html
Read it several times. If there are vaccum leaks, they will reak havac on the idling and performance of the car. The vaccum leaks will cause the computor to do some screwing things.
Thread Starter
Racer
Joined: Sep 2005
Posts: 359
Likes: 0
From: Shoemakersville Pa
Ok this is fun stuff here. Tunning tha 82 can ba a PIA but once you get it down its easy. I know I have done it myself. The timing should hold steady. You might have a worn out timing chain or something. Since the computer controls the car then the timing could jump around if the computer is telling it to. Check out this link:
http://www.corvettefever.com/techart...ing/index.html
Read it several times. If there are vaccum leaks, they will reak havac on the idling and performance of the car. The vaccum leaks will cause the computor to do some screwing things.
http://www.corvettefever.com/techart...ing/index.html
Read it several times. If there are vaccum leaks, they will reak havac on the idling and performance of the car. The vaccum leaks will cause the computor to do some screwing things.
My buddy just bought the car, it only has 36,000mi. sat for most of its life. I'm not thinking it's the timing chain (yet). I've read the corvettefever article a couple of times. Seems like a complicated proceedure. The only thing it states that we did'nt do is plug the air filter vacuum line (which would give a vacuum leak) since we did the timming with the air cleaner off. We'll try that tonight. But I still don't know why the vacuum would make the timming jump around since the computer should'nt be a factor with the ECM disconnected
Burning Brakes
Joined: Jan 2006
Posts: 1,154
Likes: 1
From: St Augustine FL
I set my timing 10 degrees btc. I am also running the hyperchip. To tune this car right you will need a manometer (preferably digital) I got mine off ebay for $65, A multimeter or scanner (I got a year specific scanner of ebay for $20.00), Timming light and a drill with a grinding bit and I forget what size drill bit for popping the welsh plugs out and then your other standard tools for tuiing a car. Oh ou will need something to plug the IAC passages. Duct tape worked for me. There are several threads about this subject. I will go find them and post the links here. Once you get down to it, the process should only take around an hour. Follow the steps closely. If you screw one step up you have to do the whole process over.
Burning Brakes
Joined: Jan 2006
Posts: 1,154
Likes: 1
From: St Augustine FL
This is a good thread to read. This guy had a nightmare mess with his car that turned out to be something simple.
http://forums.corvetteforum.com/show....php?t=1603298
http://forums.corvetteforum.com/show....php?t=1603298
Burning Brakes
Joined: Jan 2006
Posts: 1,154
Likes: 1
From: St Augustine FL
Burning Brakes
Joined: Jan 2006
Posts: 1,154
Likes: 1
From: St Augustine FL
Melting Slicks
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
Thanks Bluesilver 82. This seems to be a touchy subject.
My buddy just bought the car, it only has 36,000mi. sat for most of its life. I'm not thinking it's the timing chain (yet). I've read the corvettefever article a couple of times. Seems like a complicated proceedure. The only thing it states that we did'nt do is plug the air filter vacuum line (which would give a vacuum leak) since we did the timming with the air cleaner off. We'll try that tonight. But I still don't know why the vacuum would make the timming jump around since the computer should'nt be a factor with the ECM disconnected
My buddy just bought the car, it only has 36,000mi. sat for most of its life. I'm not thinking it's the timing chain (yet). I've read the corvettefever article a couple of times. Seems like a complicated proceedure. The only thing it states that we did'nt do is plug the air filter vacuum line (which would give a vacuum leak) since we did the timming with the air cleaner off. We'll try that tonight. But I still don't know why the vacuum would make the timming jump around since the computer should'nt be a factor with the ECM disconnected
Sounds like its surging then calming (lack of a better word). Could be lots of things...low fuel pressure...vaccum leak, etc.
Its all about air, gas, and temp on these cars. Check for vaccum leaks first...if you have any no matter what else you do you will never get it to run right.
jim
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Thread Starter
Racer
Joined: Sep 2005
Posts: 359
Likes: 0
From: Shoemakersville Pa
Disconnecting the Tan doesn't disable the ECM....just the advance.
Sounds like its surging then calming (lack of a better word). Could be lots of things...low fuel pressure...vaccum leak, etc.
Its all about air, gas, and temp on these cars. Check for vaccum leaks first...if you have any no matter what else you do you will never get it to run right.
jim
Sounds like its surging then calming (lack of a better word). Could be lots of things...low fuel pressure...vaccum leak, etc.
Its all about air, gas, and temp on these cars. Check for vaccum leaks first...if you have any no matter what else you do you will never get it to run right.
jim
Melting Slicks
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
Last evening we disconected and pluged the vacuum lines right off the rear of the intake (there was two of them) made a little difference at idle. Found that the vacuum hose from the intake to what looks like a solenoid mounted on the drivers side inner fender was leaking. Put everthing back together with a new vacuum hose, but still is not right. Started checking the bolts that hold down the throttle bodies plate to the intake half of them were under 12lbs. I don't know what the torque spec is for these bolts and the throttle body bolts (did'nt want to overtighten them) we torqed everything to 14lbs, this was the torque of the tightest bolt. Does anyone know what this torque is supposed to be? From the sound of everyones help the first thing is to fix any vaccum leaks then proceed from there.
Jim
Thread Starter
Racer
Joined: Sep 2005
Posts: 359
Likes: 0
From: Shoemakersville Pa
