LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

More Optispark Woes (in a Chevelle)....?

Thread Tools
 
Search this Thread
 
Old Aug 20, 2006 | 03:05 AM
  #1  
WS6NIGHTMARE's Avatar
Thread Starter
Registered User
 
Joined: Jun 2004
Posts: 546
From: Webster,Tx
More Optispark Woes (in a Chevelle)....?

Ok, so Ive been helping a friend do a LT1 swap into a Chevelle. Time to get it started, but nooooo that would be too easy. So here it is.

Intially it started and ran for about 10 seconds or so, died. This was 1 time. After that it would just kinda pop but not actually turn over and go. Sparks was not consistant at the plugs either. Today, not putter at all, just turning. No spark at plugs either. Pulled the Opti and brushed off the contacts just to see if it reacted any different. Nope, still nothing and no spark at the plugs. Opti has about 70k on it.

Also pulled the wire from the coil and stuck a screwdriver in there, nothing either, but it checks out on the Voltmeter. Dont know how to test the module, but put a good one in there, nothing still.

Car is using a 93 or 94 Caprice motor, i dont remember, and using the same wiring harness. Im aware thats probably not the best one to use, its a little over-complicated for the application, but its what we got right now.

So do yall think its the Opti? Im open to other suggestions. Car is soooo close and yet so far away.
Old Aug 20, 2006 | 07:25 AM
  #2  
Guest47904's Avatar
Guest
 
Joined: Sep 2004
Posts: 0
Re: More Optispark Woes (in a Chevelle)....?

If you don't have spark, start with the basics at the ignition system. With KOEO, you should have 12 volts on 2 of the wires at the ICM. Ground on another and the white wire will bring the trigger signal from the PCM to the ICM. The white wire signal will be between 1 and 4 volts AC (not DC) while cranking.

Let us know what you find.
Old Aug 20, 2006 | 03:08 PM
  #3  
WS6NIGHTMARE's Avatar
Thread Starter
Registered User
 
Joined: Jun 2004
Posts: 546
From: Webster,Tx
Re: More Optispark Woes (in a Chevelle)....?

KOEO...meaning key on right?

Ya Im not too familiar with the harness workings so these are the things I need.
Old Aug 20, 2006 | 03:52 PM
  #4  
JimboManJones's Avatar
Registered User
 
Joined: Jan 2006
Posts: 308
From: Long Island
Re: More Optispark Woes (in a Chevelle)....?

Originally Posted by WS6NIGHTMARE
KOEO...meaning key on right?

Ya Im not too familiar with the harness workings so these are the things I need.
I think it might mean, Key On Engine Off
Old Aug 20, 2006 | 08:40 PM
  #5  
Dave89IROC's Avatar
Registered User
 
Joined: Aug 2002
Posts: 4,676
From: Melvindale, MI, US
Re: More Optispark Woes (in a Chevelle)....?

Originally Posted by JimboManJones
I think it might mean, Key On Engine Off
correct, and KOER is key on engine running
Old Sep 7, 2006 | 03:29 PM
  #6  
SSCamaro's Avatar
Registered User
 
Joined: Sep 2000
Posts: 382
From: VA
Re: More Optispark Woes (in a Chevelle)....?

That could go both ways, it should be changed or it might screw someone up real bad that doesnt know it, like me, well, now I know.
Old Sep 7, 2006 | 07:11 PM
  #7  
WS6NIGHTMARE's Avatar
Thread Starter
Registered User
 
Joined: Jun 2004
Posts: 546
From: Webster,Tx
Re: More Optispark Woes (in a Chevelle)....?

Sorry I havent gotten back to this thread, Ive been workin non stop since i posted it and I havent gotten back to my friends house to check it out some more....he refuses to test electrical without me there
Old Sep 7, 2006 | 07:44 PM
  #8  
93redz's Avatar
Registered User
 
Joined: Mar 1999
Posts: 157
Re: More Optispark Woes (in a Chevelle)....?

I know you said you have no spark but did you check to see if you have fuel? I did a LT1 in a 69 camaro and it had a similar start condition and it was the vats that needed bypassed.When i sprayed starting fluid in the intake it would fire.If it has fuel and no spark i have a trouble shooting guide for that if you need it.
Old Sep 7, 2006 | 07:45 PM
  #9  
WS6NIGHTMARE's Avatar
Thread Starter
Registered User
 
Joined: Jun 2004
Posts: 546
From: Webster,Tx
Re: More Optispark Woes (in a Chevelle)....?

Actually it has the VATS bypass module hooked up.
Old Sep 7, 2006 | 08:03 PM
  #10  
93redz's Avatar
Registered User
 
Joined: Mar 1999
Posts: 157
Re: More Optispark Woes (in a Chevelle)....?

If you dont have spark at the coil i dont think its the opti.I just went through all this on mine and it ended up being a bad connection between the the coil and ignition module.Im not saying thats your problem but the way i understand it is the coil fires the opti and if there is no fire at the coil i would try to get fire there first.
Old Sep 7, 2006 | 09:23 PM
  #11  
MEAN LT1's Avatar
Registered User
 
Joined: Aug 2001
Posts: 1,983
From: Jacksonville,fla
Re: More Optispark Woes (in a Chevelle)....?

I agree with the above that its not the opti. If you havent tried another icm then I would do that and work from there. People are soo quick to blame the opti.
Old Sep 7, 2006 | 09:53 PM
  #12  
3DFORMULA's Avatar
Registered User
 
Joined: Jul 2006
Posts: 309
From: Bartonville, Ill
Re: More Optispark Woes (in a Chevelle)....?

The coil does not fire the opti. The coil fires the cap and rotor. If you do not have spark at the coil it very well could be the opti. It(spark signal) comes from opti to the computer, then to the coil.
Old Sep 8, 2006 | 03:30 PM
  #13  
93redz's Avatar
Registered User
 
Joined: Mar 1999
Posts: 157
Re: More Optispark Woes (in a Chevelle)....?

I agree with you. I worded that wrong. I meant that the coil sends the spark through the cap and if you dont have spark at the coil you are not going to have it through the cap either.If he has resolution signal from the opti then the opti could be fine.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Formula Steve
LT1 Based Engine Tech
45
Sep 19, 2023 08:31 AM
Jeff1904
General 1967-2002 F-Body Tech
5
Jun 5, 2016 05:00 PM
PopoFormula
LT1 Based Engine Tech
5
Oct 12, 2015 04:19 PM
football4life
Cars For Sale
2
Oct 4, 2015 07:48 AM
colts0455
LT1 Based Engine Tech
5
Sep 27, 2015 01:07 PM




All times are GMT -5. The time now is 10:30 AM.