First ile start by saying that I took my '97 z28 into the shop a few weeks ago and had my pcm read because I was getting a Crankshaft position sensor code. I was told that it was getting an inconsistent signal from my optispark and that signal gets synced up with the crankshaft sensor and that I need to replace the opti (quoted at $1200). So i decided to do the work myself. After replacing everything I fired her up but Im still getting the same CKP code. But the real problem is that it Idles like a champ but once I put it into gear I lose about 500 rpms and have no power at all. I couldn't even back out of my drive way. The car was running and driving fine before the opti swap but I was suffering a noticable mpg loss. The guy at the shop said that my pcm was compensating by dumping more fuel into the sysem because of the wacky reading from my opti. I've asked around to local diy guys and they say it sounds like a timing issue. However I understand that there is no timing adjustment on these and that Its all controlled by the pcm. Is it possible that my pcm needs to relearn the new sensor in the optispark? Do I need to get my PCM retuned? I'm on a budget and can't afford to keep throwing money at it. So PLEASE someone HELP!!!

 

I know the feeling. first what kind of opti did you use? second did you do plugs and wires? have you had your fuel pump checked? have you checked your injectors?

honestly that's about how my car runs when im out of gas and pushed it to far...

 

Your mechanic didn't know what he was talking about. In the 97 LT1 the CKP is used to detect misfires, it has nothing to do with the opti, and has nothing to do on how the engine runs. The CKP code is probably due to a bad CKP or the wiring connecting the CKP.
Was the engine running properly before the opti transplant??
If the engine was running properly before the opti was replaced, then the new opti is bad, or not installed properly.
The PCM looks to the opti for timing signals to determine spark and injector timing, and there is no learning curve involved. The PCM will set codes if it does not see the timing signals (high & low res) or if their relationship is off. The learning curve is related to idle speed, fuel mixture, and automatic transmission shift quality. As we used to say in Brooklyn, "Foget about the PCM tuning" your problems are not in the PCM. Rescan for codes and let us know what they are. There may be stored codes even though the CEL is off.

 

I used a new Opti from Napa auto for $220. And yes ive recently done plugs and wires. Plenty of premium fuel in it and it was running before the opti swap just not effeciently (8mpg). I did another visual check of everything and checked all the routing of the wires and they were right. But during my check I noticed that my passenger exhaust manifold was glowing red after idleing for about 15 mins.

If the opti wasn't installed right I shouldn't be able to crank it over and idle good right? I also noticed a louder sucking sound from my CAI that ive never heard before but that may be because I just cleaned my filter? After reading a few other forums It sounds like if your air to fuel ratio has too much air in the equation that it will make it run rich and maybe thats where my glowing hot exhaust manifold is coming from?
Ive checked for codes and all ive come up with is P0335 (CKP Circuit) P0336 (CKP)

My last question is does my #1 cylinder need to be at TDC when installing the opti? Ive read that it doesnt matter because of the automatic timing from the pcm. I appreciate any responses and Im sure Ile be able to get this Z28 burning rubber again with your help! Thanks

 

double tripple check the plug wires to make sure there in the right place. very easy to get some of them crossed. opti can only go in one way if its installed correctly. did you notice a brand name on the new opti? not uncommon nowdays to get a bad opti new.

 

Glowing manifold, but only on one side? Maybe your cat is toasted and clogged?

 

A glowing exhaust mainifold is not a good thing, many reasons for that including heavy misfire, retarded spark, bad exhaust valve, etc..,but the end result is that the fuel is being burned in the exhaust manifold rather than in the engine, and is also a good reason for bad gas mileage.

The sucking noise could be a leak in the intake air path, and a clean air filter does not create more noise.

I don't know what you were reading, but too much air is not going to cause a rich mixture; however it can cause the mixture to go lean.

For the time being, do not worry about the CKP as it does not affect how the engine run, but get the other stuff fixed first.

It does not matter if the engine is at TDC or not when installing the opti, as it is keyed to only go in one way; however, it can be forced in wrong by not aligning it properly before tightening the screws. Forcing it in wrong can cause stress and damage the internal stuff.

By the way, burning rubber is not a good test on how a car performs. lol

 

The fact that your engine is now running like a dog after the new opti, is making me think you could have forced the opti on in the wrong position. The most common reason for a doggy engine, along with glowing exhaust manifold(s), is retarded ignition timing.

 

If the opti is installed correctly, then you probably got a bad one. Do you have your original opti? If you do, swap it back on and see if the car runs correctly (or at least as good as it did before the opti swap).

Then work on the other problems, and as always, scan for codes often and tackle them one at a time.

 

Thanks for the advice guys but the plugs & wires are all good and I didn't force the opti on. Some new info is that my car, pcm, and wiring harness are from my '97 but the engine is a '94. My drive pin in the opti was machined down from the '97 to exact specs of the '94 to fit on the cam. And theres nothing wrong with the machine job because it was running before the swap. My problem has to be Timing right? But why is my Pcm having trouble with the position of the pistons? The only thing that hasn't been checked since the swap is the Pcm readings. It looks like I need to hire a mechanic with the ability to get into the pcm and see exactly what my computer is seeing right? Has anyone else ever had problems with their computer not reading the new signal from the opti sensor? Could i just go back to a new '94 opti? Would my Pcm be able to read that? Thanks for your help Pete and your probably right cuz new tires every 4 months was starting to get expensive! haha