95/96 Opti Install
Thread Starter
Race Director
Joined: Jan 2002
Posts: 12,261
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From: O'Fallon Missouri
95/96 Opti Install
Just finished a camshaft install, and did the 95/96 opti upgrade. Tried to start the car this afternoon, and it barley idles, sputters, and smokes. Does it sound like the opti was installed incorrectly, I could swear I installed it right? Would the car even run if the opti was installed wrong? I traced the plug wires on the passenger's side, and the are correct. I will need to pull a few things on the driver's side to check the wires.
Any other ideas, before I tear this thing back apart?
-Mike
Any other ideas, before I tear this thing back apart?
-Mike
Safety Car
Joined: Dec 2002
Posts: 3,655
Likes: 24
From: Charleston SC
Is the check valve for the vacume installed correct? If not it will cause the cap to suck in and hit the rotor, ask me how I know. Try disconnecting the vacume lines and see if it helps,
Other then that I would think firing order
Other then that I would think firing order
Thread Starter
Race Director
Joined: Jan 2002
Posts: 12,261
Likes: 85
From: O'Fallon Missouri
Didn't degree the camshaft.
Almost certain the opti vacuum lines are correct.
Hoping the drivers side spark plug wires are switched up. I wouldn't think the car would run if the opti was installed wrong.
Almost certain the opti vacuum lines are correct.
Hoping the drivers side spark plug wires are switched up. I wouldn't think the car would run if the opti was installed wrong.
Drifting
Joined: Jun 2001
Posts: 1,997
Likes: 1
From: Lake Ozark MO
Mike,
The vacuum lines would have nothing to do with it.
If you installed the Opti on the wrong slot (pin-wise) then it would be firing about 120 degrees off normal and bucking like a son-of-a-gun. So that may be a possiblility. It takes effort to install the Opti on the wrong slot. You'd have to really muscle it on. The correct slot is an easy fit.
Was the Opti a tough fit?
If not then you have to fall back on either cam timing or wiring.
Sorry to hear about the situation.
The vacuum lines would have nothing to do with it.
If you installed the Opti on the wrong slot (pin-wise) then it would be firing about 120 degrees off normal and bucking like a son-of-a-gun. So that may be a possiblility. It takes effort to install the Opti on the wrong slot. You'd have to really muscle it on. The correct slot is an easy fit.
Was the Opti a tough fit?
If not then you have to fall back on either cam timing or wiring.
Sorry to hear about the situation.
Melting Slicks
Joined: May 2005
Posts: 2,730
Likes: 1
From: Atoka Oklahoma
St. Jude Donor 06
sounds like opti is right, i am leaning on crossed up plug wires. let us know either way. i am not sure if it'll help or not but i would double check wires are seated solid on opti.
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by STL94LT1
Just finished a camshaft install, and did the 95/96 opti upgrade. Tried to start the car this afternoon, and it barley idles, sputters, and smokes. Does it sound like the opti was installed incorrectly, I could swear I installed it right? Would the car even run if the opti was installed wrong? I traced the plug wires on the passenger's side, and the are correct. I will need to pull a few things on the driver's side to check the wires.
Any other ideas, before I tear this thing back apart?
-Mike
Any other ideas, before I tear this thing back apart?
-Mike
Mike did you check the short wire harness between the opti and the main harness connector at the intake manifold. I think the early short harness was different in some what with the later 95 harness, I would have to compare the two together, but if memory serves me right the 92/94 harness had one less wire than the 95/97 LTx harnesses. I have both at the shop so I can take a look tomorrow if you haven't sorted this out by then.
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Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
I don't see how it can be done, but I've heard of people having the Opti-Spark installed with the pin in the wrong hole -- in fact, one magazine article stated they did exactly that.
The missing wire in the later Opti-Spark is just a ground wire for a shield that GM decided not to use on the later Opti-Spark harness.
Tom Piper
The missing wire in the later Opti-Spark is just a ground wire for a shield that GM decided not to use on the later Opti-Spark harness.
Tom Piper
Thread Starter
Race Director
Joined: Jan 2002
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From: O'Fallon Missouri
Originally Posted by tjwong
Mike did you check the short wire harness between the opti and the main harness connector at the intake manifold. I think the early short harness was different in some what with the later 95 harness, I would have to compare the two together, but if memory serves me right the 92/94 harness had one less wire than the 95/97 LTx harnesses. I have both at the shop so I can take a look tomorrow if you haven't sorted this out by then.
The driver's side spark plugs are correct at the spark plugs. But, I may have reversed the order at the opti. I'll pull a few parts off this afternoon and check the plug wire order.
Also, I pulled the opti off breifly after it was first installed, I know for certain it was installed right at this time. Maybe when I put it back on it was misaligned. but, it slid right on.
Now I'm starting to second guess everything.
Guess I'll see this afternoon.-Mike
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by STL94LT1
Tom, my 94 has the same 4 wires as the new harness. But, I had to cut an alignment rib out of the inside of the opti harness to the engine wire harness plug.
The driver's side spark plugs are correct at the spark plugs. But, I may have reversed the order at the opti. I'll pull a few parts off this afternoon and check the plug wire order.
Also, I pulled the opti off breifly after it was first installed, I know for certain it was installed right at this time. Maybe when I put it back on it was misaligned. but, it slid right on.
Now I'm starting to second guess everything. Guess I'll see this afternoon.
-Mike
The driver's side spark plugs are correct at the spark plugs. But, I may have reversed the order at the opti. I'll pull a few parts off this afternoon and check the plug wire order.
Also, I pulled the opti off breifly after it was first installed, I know for certain it was installed right at this time. Maybe when I put it back on it was misaligned. but, it slid right on.
Now I'm starting to second guess everything.
Guess I'll see this afternoon.-Mike
Safety Car
Joined: Dec 2002
Posts: 3,655
Likes: 24
From: Charleston SC
Originally Posted by Dan Parker '96
Mike,
The vacuum lines would have nothing to do with it.
If you installed the Opti on the wrong slot (pin-wise) then it would be firing about 120 degrees off normal and bucking like a son-of-a-gun. So that may be a possiblility. It takes effort to install the Opti on the wrong slot. You'd have to really muscle it on. The correct slot is an easy fit.
The vacuum lines would have nothing to do with it.
If you installed the Opti on the wrong slot (pin-wise) then it would be firing about 120 degrees off normal and bucking like a son-of-a-gun. So that may be a possiblility. It takes effort to install the Opti on the wrong slot. You'd have to really muscle it on. The correct slot is an easy fit.
Safety Car
Joined: Dec 2002
Posts: 3,655
Likes: 24
From: Charleston SC
I am sure you already have done this but double check all the sensors and anything (such as vacuum lines, EGR, Air tubes) that where disconnected during the install, a vacuum check with a gauge wouldn't hurt either.
I also haven’t seen anything on valve lash posted yet, are you fairly comfortable with your procedure for adjusting the rockers? I have seen problems similar to yours when the rockers where to tight.
I also haven’t seen anything on valve lash posted yet, are you fairly comfortable with your procedure for adjusting the rockers? I have seen problems similar to yours when the rockers where to tight.
Thread Starter
Race Director
Joined: Jan 2002
Posts: 12,261
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From: O'Fallon Missouri
Update
Well, I pulled the opti, it was installed right. Also, the plug wires were in place. Checked the valve adjustments, had one intake a little loose. Started the car, same thing. Checked for codes, and got a code 33 high MAP. Let the car spudder for a few seconds to record some data, and my MAP values are staying in the ~90kpa range at idle. Could a bad MAP sensor cause my problems? Doesn't make sense that I wasn't having a MAP problem before this install.
Melting Slicks
Joined: May 2005
Posts: 2,730
Likes: 1
From: Atoka Oklahoma
St. Jude Donor 06
well all be....guessing can get expensive. at least you check previous work and now you won't have to second guess yourself. 
from what you first posted i was leaning to a crossed wired, at least that is what it sounded like. it is kinda hard to believe something else could go bad just sitting there. got me on this.
also..good follow up.
from what you first posted i was leaning to a crossed wired, at least that is what it sounded like. it is kinda hard to believe something else could go bad just sitting there. got me on this.also..good follow up.
Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
Originally Posted by STL94LT1
Well, I pulled the opti, it was installed right. Also, the plug wires were in place. Checked the valve adjustments, had one intake a little loose. Started the car, same thing. Checked for codes, and got a code 33 high MAP. Let the car spudder for a few seconds to record some data, and my MAP values are staying in the ~90kpa range at idle. Could a bad MAP sensor cause my problems? Doesn't make sense that I wasn't having a MAP problem before this install.
Originally Posted by FD2BLK
Is the check valve for the vacume installed correct? If not it will cause the cap to suck in and hit the rotor, ask me how I know. Try disconnecting the vacume lines and see if it helps,
Other then that I would think firing order
Other then that I would think firing order
Correct me if I am wrong here, but I think you just installed a vacuum vented Opti-Spark and now you are having MAP readings out of range.
My guess is the vacuum vent is the problem.
To prove it, temporarily plug the vacuum from the manifold (plug it at the manifold) for the Opti vacuum vent. If everything clears up, you need to address the problem with the vacuum vent on the Opti.
Tom Piper
Last edited by Tom Piper; Jun 13, 2005 at 07:37 AM.
Melting Slicks
Joined: Apr 2003
Posts: 2,150
Likes: 6
From: NS
Originally Posted by STL94LT1
Well, I pulled the opti, it was installed right. Also, the plug wires were in place. Checked the valve adjustments, had one intake a little loose. Started the car, same thing. Checked for codes, and got a code 33 high MAP. Let the car spudder for a few seconds to record some data, and my MAP values are staying in the ~90kpa range at idle. Could a bad MAP sensor cause my problems? Doesn't make sense that I wasn't having a MAP problem before this install.
Does the cam you installed have high valve overlap? If so your manifold pressure might be that high. It might just be a tuning issue. If it is then advancing your base ignition timing should help, also increase your idle speed.
Are you sure the cam is timed properly?
Team Owner
Joined: Sep 2003
Posts: 25,295
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From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
It is insanely easy to install the opti wrong. The damn rotor will spin during installation if you do not hold it in place.
If it happend to me it can happen to you.
Yes, the car will run, poorly, if you install it wrong.
If it happend to me it can happen to you.
Yes, the car will run, poorly, if you install it wrong.
Thread Starter
Race Director
Joined: Jan 2002
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From: O'Fallon Missouri
Originally Posted by Atok
Could be, just verify your MAP sensor readings using a good old fashion vacuum gauge. 90kpa is around 3 in. hg of vacuum.
Also, just remembered that when I had the intake off. I cleaned it with engine cleaner and a water hose. Dummy me, forgot to remove the MAP. I'm hoping it got wet, and a damaged MAP sensor is my problem. If not, I'm stumped.
-Mike