Optispark question
Thread Starter
Racer
Joined: Sep 2005
Posts: 417
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Optispark question
My car wont start. We took off the wires to the optispark and we're not getting a spark. So we know thats the problem. My water pump isnt leaking though....so is it possible the optispark itself isnt bad and just the wires?
Racer
Joined: Apr 2004
Posts: 482
Likes: 0
From: Wilmington NC
The coil wire would have to fail completely, or the coil itself. You could probably have several plug wires go bad and it will still start but run of course very rough.
Is there spark at the coil wire connection?
Is there spark at the coil wire connection?
Le Mans Master
Joined: May 2005
Posts: 7,334
Likes: 2,260
From: Central Maryland
If there have been no codes set, the optical section of the Optispark should be working, and should be feeding good camshaft position data to the ECM. This should allow the ECM to trigger the coil.
Check for spark at the coil (disconnect the coil wire from the Opti, and see if you can see spark there). If you have spark there, but have no spark coming out of any of the spark plug wires, you've probably had a rotor failure or a carbon track from the coil contact to ground inside of the Opti.
If you have no spark at the coil wire, but no codes have been set, follow Larry's advice about checking the coil control module (it's right next to the coil), and the coil itself.
Be well,
SJW
Check for spark at the coil (disconnect the coil wire from the Opti, and see if you can see spark there). If you have spark there, but have no spark coming out of any of the spark plug wires, you've probably had a rotor failure or a carbon track from the coil contact to ground inside of the Opti.
If you have no spark at the coil wire, but no codes have been set, follow Larry's advice about checking the coil control module (it's right next to the coil), and the coil itself.
Be well,
SJW
Melting Slicks
Joined: Jul 2003
Posts: 3,222
Likes: 48
From: Pomfret, CT
Finalist 2020 C4 of the Year - Unmodified
Just a note....just because your water pump is good, doesn't mean the opti is ok. My water pump wasn't leaking, and my opti died. If you do have to change the opti, change the water pump anyway....good or not. Just my .02.
Le Mans Master
Joined: May 2005
Posts: 7,334
Likes: 2,260
From: Central Maryland
Originally Posted by Achilleus07
how do i test these things for spark?
Pull the coil wire loose from the Opti. Leave it connected to the coil. Take a spare spark plug, and connect the coil wire to the plug. Connect a jumper wire from the steel body of the spark plug to a good engine ground. Crank the engine, and look for spark jumping across the gap of the spark plug.
If you have spark at the coil, reconnect the coil wire to the Opti, and test for spark the same way at the plug wires -- disconect plug wire from plug (leave it connected to Opti), then crank and observe. Spark at each plug wire should only occur 1/8 as often as at the coil wire.
Leave the spark plugs in the engine while doing this test. You don't want air/fuel mixture to be shooting out of the spark plug holes while you're cranking the engine, especially with sparks occurring in that area.
Be well,
SJW
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Le Mans Master
Joined: May 2005
Posts: 7,334
Likes: 2,260
From: Central Maryland
Originally Posted by cicch95
Just a note....just because your water pump is good, doesn't mean the opti is ok. My water pump wasn't leaking, and my opti died. If you do have to change the opti, change the water pump anyway....good or not. Just my .02.
Consider the DynaSpark as a replacement, rather than the OEM Opti. Also consider a 160* thermostat when replacing the water pump, as this will allow you to have the ECM reflashed to kick the cooling fans on at lower temperatures, which can help to keep under-hood temps lower.
<note: GM does not offer a 160* thermostat for the LT1/LT4. You can get one made by Hypertech at a well-stocked speed shop. Just make damned sure that the 'stat is made for an LT1/LT4, as they are NOT the same as for other small-block Chevy engines.>
Be well,
SJW