C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Quick opti question....

Thread Tools
 
Search this Thread
 
Old 03-17-2014, 12:14 PM
  #1  
ChrisWhewell
Pro
Thread Starter
 
ChrisWhewell's Avatar
 
Member Since: Jan 2009
Location: Austin Texas
Posts: 686
Received 4 Likes on 4 Posts
Default Quick opti question....

My 93 still isn't starting. Fuel pressure good, fuses all good, injectors have pulse, drained tank put new fuel in, new fuel filter, MAP sensor tests good. I crank it and it almost starts, like it wants to start but just doesn't quite start. There is spark, but i'm wondering maybe opti is bad ?

I have a spare optispark unit from a 95 LT1 vette, motor had 25k on it when rod bearing went. The opti looks new but been sitting in garage in a box 4 years. Any reason I would not want to swap to this one ? It has the vent nipple on it. I think I read where optis are different , different years. Does anybody know if the '95 opti is a direct drop-in replacement for the '93 opti, or are the drives different or some other reason I can't swap one for the other ? Thank you very much
Old 03-17-2014, 12:57 PM
  #2  
bassackwards
Pro
 
bassackwards's Avatar
 
Member Since: Aug 2012
Location: Nashville TN
Posts: 663
Likes: 0
Received 0 Likes on 0 Posts

Default

Won't fit, drives are different
Old 03-17-2014, 01:03 PM
  #3  
01 Coupe
Racer

 
01 Coupe's Avatar
 
Member Since: Jul 2003
Location: Denton, TX My goal in life is to be as good of a person that my dog already thinks I am.
Posts: 332
Received 23 Likes on 17 Posts

Default

Like Bass said, drives are different for the '95 and "96's. Besides optis are never a quick change and if you are not sure that's the problem you are creating a bunch of work for yourself. Just my .02.
Old 03-17-2014, 01:08 PM
  #4  
dizwiz24
Race Director
 
dizwiz24's Avatar
 
Member Since: Sep 2001
Location: NEwhere Ohio
Posts: 13,331
Received 559 Likes on 436 Posts

Default

cant he convert his motor to use it?

Id rather convert to use a new old stock gen 2 opti vs. Buy some piece of crap china gen 1 optispark. Though you might be able to pay top dollar and find a new old stock gen 1 optispark if you look hard enough.

The vacuum vented setup, of the gen 2, should work better. Way more reliable setup... Though you can/should easily convert a gen 1 to vented setup.

I have my 93 converted to use a gen 2 optispark. I had to so i could use the lt4 extreme duty timing chain kit.

I also put a new cam in.

My memory is failing right now (its saint patricks day) And i cant tell you all the parts i needed to do this.

Bassackwards, werent you the guy in TN that i sold my old new old stock optispark, with custom vent, to?

I bet its still working good!

Last edited by dizwiz24; 03-17-2014 at 01:10 PM.
Old 03-17-2014, 01:29 PM
  #5  
STL94LT1
Race Director
 
STL94LT1's Avatar
 
Member Since: Jan 2002
Location: O'Fallon Missouri
Posts: 12,258
Received 81 Likes on 71 Posts

Default

List of parts to convert his 93 to a gen II opti.

Gen II vented opti
Opti vaccuum harness
Opti wire harness
Gen II timing cover
Camshaft change
Old 03-17-2014, 03:26 PM
  #6  
ChrisWhewell
Pro
Thread Starter
 
ChrisWhewell's Avatar
 
Member Since: Jan 2009
Location: Austin Texas
Posts: 686
Received 4 Likes on 4 Posts
Default

thanks ya'all, I was afraid of that. Too bad the drives aren't interchangeable. By the time I change opti and pull the manifold for a cam change, I"m thinking I might just as well pull the motor to make it all easier. I just wish I could get her running again
Old 03-17-2014, 03:29 PM
  #7  
DanielRicany
Melting Slicks
 
DanielRicany's Avatar
 
Member Since: Jun 2013
Posts: 3,065
Received 36 Likes on 34 Posts
Default

If you spray some starting fluid through the intake, do you get a different response from the engine? Almost likes its firing up?
Old 03-17-2014, 04:00 PM
  #8  
dizwiz24
Race Director
 
dizwiz24's Avatar
 
Member Since: Sep 2001
Location: NEwhere Ohio
Posts: 13,331
Received 559 Likes on 436 Posts

Default

If you gotta do a cam change, now is a good time to do hotcam mod.

I would have traded you my old new old stock gen 1 opti w/ custom vent harness for this opti you have - if you would have posted this in 2012!

Last edited by dizwiz24; 03-17-2014 at 04:03 PM.
Old 03-17-2014, 08:45 PM
  #9  
Tom400CFI
Team Owner
Pro Mechanic
 
Tom400CFI's Avatar
 
Member Since: Aug 2004
Location: Park City Utah
Posts: 21,544
Received 3,181 Likes on 2,322 Posts

Default

Originally Posted by ChrisWhewell
My 93 still isn't starting. Fuel pressure good, fuses all good, injectors have pulse, drained tank put new fuel in, new fuel filter, MAP sensor tests good. I crank it and it almost starts, like it wants to start but just doesn't quite start. There is spark, but i'm wondering maybe opti is bad ?
Well...you checked at least ONE of the critical elements required to start and engine...ave you checked the other? Is there good fuel pressure?
Old 03-18-2014, 07:32 AM
  #10  
ChrisWhewell
Pro
Thread Starter
 
ChrisWhewell's Avatar
 
Member Since: Jan 2009
Location: Austin Texas
Posts: 686
Received 4 Likes on 4 Posts
Default

Originally Posted by DanielRicany
If you spray some starting fluid through the intake, do you get a different response from the engine? Almost likes its firing up?

No. Yet, there's spark at the coil. But, different plug wires , when I put a spark plug in the boots and crank it and observe them, the spark is visibly different on some than others
Old 03-18-2014, 07:32 AM
  #11  
ChrisWhewell
Pro
Thread Starter
 
ChrisWhewell's Avatar
 
Member Since: Jan 2009
Location: Austin Texas
Posts: 686
Received 4 Likes on 4 Posts
Default

Originally Posted by Tom400CFI
Well...you checked at least ONE of the critical elements required to start and engine...ave you checked the other? Is there good fuel pressure?
41 psi
Old 03-18-2014, 08:33 AM
  #12  
bassackwards
Pro
 
bassackwards's Avatar
 
Member Since: Aug 2012
Location: Nashville TN
Posts: 663
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by dizwiz24


Bassackwards, werent you the guy in TN that i sold my old new old stock optispark, with custom vent, to?

I bet its still working good!
It's still in a box on the shelf.

OP if you have good spark at the coil and erratic coming out it could be the opti. I bought a car that wouldn't start and turns out the rotor fall off.

Your cap off the newer opti will fit the older one.
Old 03-24-2014, 08:25 AM
  #13  
ChrisWhewell
Pro
Thread Starter
 
ChrisWhewell's Avatar
 
Member Since: Jan 2009
Location: Austin Texas
Posts: 686
Received 4 Likes on 4 Posts
Default

Originally Posted by bassackwards
It's still in a box on the shelf.

OP if you have good spark at the coil and erratic coming out it could be the opti. I bought a car that wouldn't start and turns out the rotor fall off.

Your cap off the newer opti will fit the older one.
Thanks. I'm pondering switching drives between the opti's, wondering if that's viable.

Or, get a new opti. In that case, oh great, another search and re-search. Help !! Anybody know what source is a good replacement opti for a '93 ??
Old 03-24-2014, 09:39 AM
  #14  
lt4obsesses
Le Mans Master
 
lt4obsesses's Avatar
 
Member Since: Dec 2006
Location: H-Town Texas
Posts: 5,139
Received 481 Likes on 261 Posts

Default

Okay, so we have good spark at the coil, and erratic spark at the plugs.

This tells me that your opti, at least on the low resolution side, the optical sensor, is functioning.

First, double check your plug wire connections, use a little dielectric grease on them. Also double check that all the wires are in the right place, as it can be easy to cross them at he opti. (I'd bet you already have, but it's worth stating) Particularly the connection of the coil wire going into the opti, it can be difficult.

It could be the distributor cap and/or the rotor. One of the main reasons they converted to a vacuum based vented design was the build up of gasses from the electrical spark that would cause the terminals to corrode.
Old 03-24-2014, 09:47 AM
  #15  
ChrisWhewell
Pro
Thread Starter
 
ChrisWhewell's Avatar
 
Member Since: Jan 2009
Location: Austin Texas
Posts: 686
Received 4 Likes on 4 Posts
Default

Originally Posted by lt4obsesses
Okay, so we have good spark at the coil, and erratic spark at the plugs.

This tells me that your opti, at least on the low resolution side, the optical sensor, is functioning.

First, double check your plug wire connections, use a little dielectric grease on them. Also double check that all the wires are in the right place, as it can be easy to cross them at he opti. (I'd bet you already have, but it's worth stating) Particularly the connection of the coil wire going into the opti, it can be difficult.

It could be the distributor cap and/or the rotor. One of the main reasons they converted to a vacuum based vented design was the build up of gasses from the electrical spark that would cause the terminals to corrode.
Fudge it, I ordered an MSD 8381, $499 including overnight shipping only $25 extra. I'll button it back up and hopefully that was the problem, if not I won't worry about the Opti anymore for a while.
Old 03-24-2014, 06:03 PM
  #16  
dizwiz24
Race Director
 
dizwiz24's Avatar
 
Member Since: Sep 2001
Location: NEwhere Ohio
Posts: 13,331
Received 559 Likes on 436 Posts

Default

Originally Posted by ChrisWhewell
Fudge it, I ordered an MSD 8381, $499 including overnight shipping only $25 extra. I'll button it back up and hopefully that was the problem, if not I won't worry about the Opti anymore for a while.
If that optispark from the 95 w/ 25000 miles is oem, I will buy it.
Old 03-25-2014, 06:39 AM
  #17  
ChrisWhewell
Pro
Thread Starter
 
ChrisWhewell's Avatar
 
Member Since: Jan 2009
Location: Austin Texas
Posts: 686
Received 4 Likes on 4 Posts
Default

Originally Posted by dizwiz24
If that optispark from the 95 w/ 25000 miles is oem, I will buy it.
OEM, yes. Its off a 95, the motor threw a rod bearing, motor had 28k on it, or 25k, I forget which. Its been in a freezer bag in my garage about 5 years. the resin looks nice shiny newm the bearing is tight, rest of it looks fresh. I have another opti off a 100k motor, its bearing is noticeablly loose, but its good for parts I guess. agent[at]inventorweb.com or 512 763-1142

Get notified of new replies

To Quick opti question....




Quick Reply: Quick opti question....



All times are GMT -4. The time now is 02:24 PM.