Story goes, my daily driver spun a main bearing, purchased another lt1 out of a 94 t/a. My car is a 95 Z28 and the man I got the engine from said it ran great but they had just bought the car to build into a 1/8 mile car for his grandson. He said he had bought the car with the optispark bad and replaced it and his grandson drove it for 2 months after that. Well installed the motor today, and then went to crank and it just cranked. While cranking i heard spark jump somewhere then realized it was from the post on the coil it was cracked. So I replaced the coil and still no spark at the plug wires. I was tired and it was getting late, so I didnt get to do much diagnosing. Just thought id post this up and see what kind of input I got. I called the man to ask him about the opti and he said he replaced it with an oem unit, and that he was certain not to get it wet upon engine removal. But it is an older non vented opti, would that have something to do with it? Installing it in a 95 car? I installed a new harness for the opti also. Could i have some sort of bad ground?

 

not certain, but something you might look into and check on, or someone else might chime in...

when i did my swap from the 94 non vented optispark engine , to the 97 vented optispark engine i transplanted..

i had to use the coil from the 94 engine on the 97 engine.

i dont know why, guess the coils are different at some point. dont know if its a difference in the vented and nonvented optisparks or possibly obd1 to obd2 computer.

a few respected individuals on this forum told me to use the older coil on the newer engine so i did, and it worked like a champ..

 

The unvented Opti (93-94) can not be installed on a 95 engine (95-97 are vented). The drive mechanism is not compatible. It is possible to swap, but would involve the wiring harness, timing cover, and timing set.

Courtesy of Shoebox:

http://shbox.com/1/93-94_opti.jpg

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

Are you sure the engine is out of a 95? See Shoebox's VIN guide:

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

Do you have the correct harness connector for the 95 Opti? The unvented and vented have different length connectors? Did the harness connector insert correctly in the Opti?

The 96/97 coils only have a single connector. The 93-95 coils have a dual connector.

 

I purchased a 94 stlye lt1 with an older non-vented opti, to install the engine in my 95 z28. I used the 94 opti on the 94 engine and yes I know about the harness differences I had already bought a new harness from Lsxtune and installed it.

 

Well done some diagnosing today and it looks like the opti is bad. Damn poorly designed things. The pink/black wire from the opti harness is grounding out, so I guess that means the optical sensor is bad?

 

The pink/black wire is the low resolution signal. That should be setting DTC 16. Prevents the engine from starting.

The big problem with the Opti seems to be the unending supply of shoddy, Chinese units, that have a life expectancy of 1 week to 1 month. The OEM (Delphi) part is much more reliable than the copies. "thepartsladi" on ebay seems to have them at good prices, and with good service.

 

I appreciate your input, I took the opti off earlier and its no good. Are the units the "thepartsladi" sells, new delphi products? I planned on trading the car in, but im not gonna cheap out and give someone else a big headache. So I guess I'll be going with a delphi.

 

Yes... AC/Delco parts are now mostly manufactured under the Delphi name.