[justin93transam]

Just put new opti in my 93 trans am. Running good first day. Then all of sudden out of no where starts running rough and backfiring like crazy. Been checking connections and plug wires. any ideas? hope i didnt get opti wet when i bleed cooling system.

[Bob]

 justin93transam, on 06 September 2009 - 11:08 AM, said:

Just put new opti in my 93 trans am. Running good first day. Then all of sudden out of no where starts running rough and backfiring like crazy. Been checking connections and plug wires. any ideas? hope i didnt get opti wet when i bleed cooling system.

What opti-spark did you use a replacement? Stock replacement? Did you spill a lot of water when you bled the system?

[Pete W]

Justin it does sound like you may have got it wet and the sensor doesn't like that at all.

[justin93transam]

I bought a newly redisigned one off ebay with a little vent on bottom. But it was runnin good for the first day. No codes. also found one of my wires is a little melted. I put some electrical tape on for now till i figure out problem. Could a bad wire be making it pop and back fire and also run real rough? NOt a lot of coolant spilled on it. just saw a little puddle on ground when i moved car from bleeders.

[Pete W]

 justin93transam, on 06 September 2009 - 12:04 PM, said:

I bought a newly redisigned one off ebay with a little vent on bottom. But it was runnin good for the first day. No codes. also found one of my wires is a little melted. I put some electrical tape on for now till i figure out problem. Could a bad wire be making it pop and back fire and also run real rough? NOt a lot of coolant spilled on it. just saw a little puddle on ground when i moved car from bleeders.

Replace the wire for sure, this is a high voltage unit.

[Bob]

Did you replace anything else when you replaced the opti?

[justin93transam]

Just replaced the opti. nothing else

Im gonna try to fix the one bad wire first. I also heard that the coolant sensor controls the injectors giving the computer a false reading will make it dump in more gas. is this true?

[Bob]

 justin93transam, on 06 September 2009 - 12:40 PM, said:

Just replaced the opti. nothing else

Im gonna try to fix the one bad wire first. I also heard that the coolant sensor controls the injectors giving the computer a false reading will make it dump in more gas. is this true?

What makes you think it's related to the coolant temp sensor?

[justin93transam]

A mechanic i know told me to check the sensor , if its bad it could tell the computer to dump more gas in. thus causing the backfiring. Never had problems with it though.

[Bob]

Can you get your hands on a scanner so you can read live sensor information while the car is running? You can eliminate almost all the sensors or find the defective sensor this way. I also know you can pull the codes from the 93 by shorting two pins, so I would check the computer for stored codes. Here is how you pull the codes on the 93:

http://shbox.com/1/dlc2.jpg

Which newly redesigned opti did you buy?

[justin93transam]

I checked it for codes already. didnt get any. The optispark is redisgned with a vented cap made by AIP electronics. i bought it off ebay from All Ignition.

[Bob]

 justin93transam, on 06 September 2009 - 03:14 PM, said:

I checked it for codes already. didnt get any. The optispark is redisgned with a vented cap made by AIP electronics. i bought it off ebay from All Ignition.

Did you use a scanner that had the capability to read live sensor data? I have never heard of that unit, can you post a link. I know a lot of people were having trouble with the MSD Opti. I wonder if you bought a bad opti.

[justin93transam]

I didnt use a scanner, just jumped the terminals to make light flash.This is the adress to the website i bought the optispark at off ebay.
http ://cgi.ebay.com/ebaymotors/92-93-94-LT1-OPTISPARK-DISTRIBUTOR-FIREBIRD-TRANS-AM_W0QQcmdZViewItemQQ_trksidZp3286Q2ec0Q2em14QQhashZitem5d260ab8f9QQitemZ400070195449QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

[Bob]

I have never heard of that company before, so I cannot comment on any issues related specifically to that company, but I do know that people have had problems with other name brand replacement opti-sparks. The symptoms you describe sound like it certainly could be a bad distributor, but there are also a lot of other things it could be. Because you just replaced the opti, I can't help but to think it's the opti that is causing your problems. Could be the fuel system, ignition system, or sensor issue. The easiest way to check sensors is with a scanner.

[Bob]

I just want to add what I would do. I would start by buying a scanner that can read live sensor data. You will use this tool all the time and it can save you a ton of cash and time. I would then re-replace the opti-spark. I know it's a royal PITA, and I know it may not be the opti, but the ONLY way to eliminate it as a possibility is to replace it. Since you uses an unknown company, I am even more suspect that it's a bad opti. If you want, you could replace other things like the engine temp sensor, map sensor, etc, or you can just test each of these sensors to eliminate them (I suggest testing them if you know how). You may end up spending a lot of money this way, but the opti you bought should have a warranty and should cost nothing to replace if you do it yourself. This is one of those situations where it's hard to know exactly what to do, so you have to make a choice about which direction you want to go in and start eliminating all the possibilities until you find the problem. Usually, if you just replace something and the problem appears soon after, there is a good probability it's related to what you just replaced. Have you tried to reset the PCM by pulling the PCM/Batt fuse for 30 seconds yet? Probably won't help since you don't have any codes, but it might be worth a try. :12EMOTICHEERS:

[Canhos]

Justin.
Did you replace that burnt wire already?
Did it help your problem at all?
Ignition wires run at thousands of volts, and to repair it with electrical tape is a temporary fix at best. Even if it's isolated from metal, the voltage can run through all the contaminants on the wire and through the tape, and will cause problems for you.

[Bob]

 Canhos, on 07 September 2009 - 10:38 AM, said:

Justin.
Did you replace that burnt wire already?
Did it help your problem at all?
Ignition wires run at thousands of volts, and to repair it with electrical tape is a temporary fix at best. Even if it's isolated from metal, the voltage can run through all the contaminants on the wire and through the tape, and will cause problems for you.

Good catch Mike, I forgot about that broken wire. I agree, fix that wire first.

[MaroRacing010]

Okay I do not know what the problem is, but I just got my opti replaced in my Camaro just the other day. Here is what I would do. Replace that bad wire, see if that is the problem, check all your vacuum hoses around the opti. If nothing turns up replace the opti. I know mine costed me $1400 to get replaced but so far, it was worth it. If you have to replace your opti, get OEM ac delco. Everyone I talked to before I replaced mine recommended that opti. Hopefully you get your car running again. Good luck!

[Bob]

 MaroRacing010, on 07 September 2009 - 03:55 PM, said:

Okay I do not know what the problem is, but I just got my opti replaced in my Camaro just the other day. Here is what I would do. Replace that bad wire, see if that is the problem, check all your vacuum hoses around the opti. If nothing turns up replace the opti. I know mine costed me $1400 to get replaced but so far, it was worth it. If you have to replace your opti, get OEM ac delco. Everyone I talked to before I replaced mine recommended that opti. Hopefully you get your car running again. Good luck!

$1,400 to replace the opti?? OUCH!

[justin93transam]

Tried disconnecting the wire completely and started it, no luck. Still back fired like crazy.I replaced it my self and i wouldnt pay someone $1400 to do the job. Its a pain but not that hard to do. One thing i kepp thinking about is when i installed it. When i inserted the shaft with the keyed splines into the cover (93's have shaft and not cammed rotor), i got it like half way in and had to tighten the bolts on the opti to get it in the rest of the way. It didnt force anything though. Could the timing be off because its not in the right way? Butt it was running great for the first day. I just hope the little bit of coolant that came from the bleeders wasnt enough to ruin the new opti. Any one know any ways to test it without removing it?