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Discussion Starter · #1 ·
I recently replaced plugs, wires, steering column guts, and opti. Can runs perfectly. I replaced the radio the other day and now it won’t start. Put the old radio back in and same result. Security light does not flash and goes off with the other dash lights. Any ideas? I’m exhausted
 

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I'd start by looking for blown fuses, even though radio has nothing to do with ignition system or fuel system. 93 can read codes with the paperclip trick. Look for codes. Even though check engine light is not on, there are codes that don't turn it on.

DTC 16, 36, 41 & 42 are all ignition related codes. Get the 93 factory service manual at the following link It will have all sorts of troubleshooting help.www.mediafire.com/?40mfgeoe4ctti

Test your car for spark. If you have spark, spray some starting fluid into intake elbow. See if engine runs for a couple of seconds, or at least tries to start.

If you have a dead ignition system you will probably have one of the codes listed above. DTC 16, & 36 are for opti. If code 16 sets engine won't run. Code 36 will let engine run but badly. Codes 41 & 42 are ICM codes. Both of these will stop engine from running.

If spark tested good on several cylinders, move to fuel system. Get a fuel pressure tester & do a key on prime. Pressure should be around 43 psi. If no you have a fuel system problem. If pressure OK, get a set of noid lights to see if fuel injectors are opening when engine cranks..

Back to ignition system. If you bought any opti besides a GM, Delco, or Delphi, it's junk. This could be your problem. Shoebox site has a way of testing if low & high resolution pulses are being sent by opti. But only 100% way to test these signals is with an oscilloscope. Both the opti signals are square waves that multimeter won;t show.
 

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Discussion Starter · #3 ·
I'd start by looking for blown fuses, even though radio has nothing to do with ignition system or fuel system. 93 can read codes with the paperclip trick. Look for codes. Even though check engine light is not on, there are codes that don't turn it on.

DTC 16, 36, 41 & 42 are all ignition related codes. Get the 93 factory service manual at the following link It will have all sorts of troubleshooting help.www.mediafire.com/?40mfgeoe4ctti

Test your car for spark. If you have spark, spray some starting fluid into intake elbow. See if engine runs for a couple of seconds, or at least tries to start.

If you have a dead ignition system you will probably have one of the codes listed above. DTC 16, & 36 are for opti. If code 16 sets engine won't run. Code 36 will let engine run but badly. Codes 41 & 42 are ICM codes. Both of these will stop engine from running.

If spark tested good on several cylinders, move to fuel system. Get a fuel pressure tester & do a key on prime. Pressure should be around 43 psi. If no you have a fuel system problem. If pressure OK, get a set of noid lights to see if fuel injectors are opening when engine cranks..

Back to ignition system. If you bought any opti besides a GM, Delco, or Delphi, it's junk. This could be your problem. Shoebox site has a way of testing if low & high resolution pulses are being sent by opti. But only 100% way to test these signals is with an oscilloscope. Both the opti signals are square waves that multimeter won;t show.
Thanks…will try today
 

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1st charge up the battery and see if it's healthy still. Get it checked out at autoparts store. Disconnect the intake at the throttle body. Open the throttle spray carb cleaner in side, with engine off. Start the car. If it runs for a second then it's a fuel problem. If nothing changes try again with a 5 second spray. If still nothing put a spark plug tester to see if the coil is firing. If you have both of them, check compression. A good lt1 has like 150 psi
 
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