hello, been trying to get my z28 back on the road... well got it running but not too well, put on new optispark, tested before installing for testing I hooked up the opti and used a drill to drive the gear and tested each port and all had spark, I installed the thing and just drove it around the block and started back fire and not running too good. I used a temp gun and pointed at each cyl header pipe, nr 1 was only around 150 degrees all others were around 350. i checked the plug wire and still same on next test except now nr2 cyl is also at 150... but now also cyl 5 is reading around 500...i then checked for spark on 1,3,5,7 and 2 cyl's all have spark, I pulled the injector wires off 1 and 2 (i have a kit to clean injectors and also spare injectors, the injectors are working and fuel pressure was good. I then put everything back together ...well cyl 1 still at 150, cly 5 has gone up to around 700, 3 and 7 still aroung 350 but now 2, 4, 6 and 8 are all at around 150... i'm thinking optispark, i have a spare but when i try to test it only flashed once then dead.... didn't try all ports. I hate to have to take off the optispark again and get another just to get junk (lifetime warranty form autozone). is there anyone who knows of a reliable optispark? thanks

 

did you replace the opti wire harness? triple check to make sure plug wires are to correct place. could be pcm or opti issues.

 

yeah new opti came with harness. sure that plug wires are good, as my first test with the temp showed around 350 degrees on all cyl except #1 , crazy thing after making sure everything was tight but second test I has dead holes in # 1 & 2. next time all holes on passengers side dead.... so yeah thinking opti spark or pcm/ecu

 

I dont think it would be ignition control module, I believe they let it run or not. at least that's what I have seen.

 

yeah I also think its not the ecu, Must be the opti, got another one today (warranty) gonna "bench" test before installing.
This is the way I test these things. I have an extra module harness and connect to the ecu and use extra ignition wire to coil and use a drill to spin the opti to check for spark at each port.
If anyone has other way to test like the input.

 

look at 28 here see if it helps any. shbox is good 4th Gen LT1 F-Body Tech Aids