94 z28 lt1 shuts off
#16
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Re: 94 z28 lt1 shuts off
I have given up suggesting you watch the tach while cranking. I guess you don't think that will help to tell if the Opti is working. Good luck.
Last edited by GaryDoug; 07-10-2016 at 01:24 PM.
#17
Re: 94 z28 lt1 shuts off
ok ran the car till it shut down again, confirmed that it will not start, so i i was watching the rpms (like somebody said) while i was cranking and they just sat there absolutely no movement, so i guess when the optispark is cool it runs fine, heats up shuts down. so i guess its my optispark, now napa has them for 300 canadian i see eBay has them for around 100
#18
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Location: Born on the Florida West Coast, now where can I retire?
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Re: 94 z28 lt1 shuts off
To make absolutely sure, wait until it cools off enough to let it start. Then shut it off immediately. remove both injector fuses and try to start again while watching the tach. It won't start, just cranks. If the needle moves then, you will be 99% sure the distributor is the problem.
You will get what you pay for. The $300 one will work first time and probably for quite a while longer. The $100 one will probably work first time but who knows for how long.
You will get what you pay for. The $300 one will work first time and probably for quite a while longer. The $100 one will probably work first time but who knows for how long.
Last edited by GaryDoug; 07-10-2016 at 01:23 PM.
#19
Re: 94 z28 lt1 shuts off
As the Opti price goes down, the chance of failure goes up. Most people will strongly recommend you bite the bullet an get an AC Delco or Delphi unit.
#20
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Re: 94 z28 lt1 shuts off
By the way, you can test a new Opti before installing it into the engine. Just connect it to the small cable only (no spark plug wires) and spin the Opti shaft while someone watches the tach with the ignition on. The tach needle should move up a bit, maybe 100-200 rpm or more depending on how fast you spin it. Try both directions. I don't remember which direction it turns. Fred may be able to help here. I recommend doing this with the injector fuses removed so as to not "fuel" the engine.
#22
Re: 94 z28 lt1 shuts off
my rpm needle sits a little lower below the 0, took the injector fuses out and cranked the engine, the rpm needle moves to just a wee bit above the zero, so does that confirm its my optispark
#23
Re: 94 z28 lt1 shuts off
By the way, you can test a new Opti before installing it into the engine. Just connect it to the small cable only (no spark plug wires) and spin the Opti shaft while someone watches the tach with the ignition on. The tach needle should move up a bit, maybe 100-200 rpm or more depending on how fast you spin it. Try both directions. I don't remember which direction it turns. Fred may be able to help here. I recommend doing this with the injector fuses removed so as to not "fuel" the engine.
#24
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Location: Born on the Florida West Coast, now where can I retire?
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Re: 94 z28 lt1 shuts off
Watch the video at the link I posted earlier. Notice how much the tach needle rises the second time he operates the starter. If it is about the same rise as yours, the opti sensor circuit is not dead and is probably ok. That does not test the cap and rotor however.
#29
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Re: 94 z28 lt1 shuts off
CP9185. They go for as little as $76 on Amazon. You will need a 120v-to-12v 2.5mm supply. They are very common, you may already have one for something else. Or you can buy the CP9127 which has it and the 12-pin cable for a 94 also.
https://www.amazon.com/Actron-CP9185.../dp/B000T8UG52
Actron/GM OBD I ALDL cable kit CP9127- Read1Reviews onActron #CP9127
https://www.amazon.com/12V-Power-Ada.../dp/B00447C4HM
https://www.amazon.com/Actron-CP9185.../dp/B000T8UG52
Actron/GM OBD I ALDL cable kit CP9127- Read1Reviews onActron #CP9127
https://www.amazon.com/12V-Power-Ada.../dp/B00447C4HM
#30
Re: 94 z28 lt1 shuts off
so this is what happened with the code reader, plugged it in did a scan, came back with dtc 47, i then noticed that it was set on 1991 so i changed it to 1994 and now it keeps say check cable and dose not retrieve any codes, so now what