Ok, making some headway...I hooked up a "check engine light" and jumped pins a and b on the aldl, the light is giving me code 36...Distibutor ignition system faulty high or extra low resolution pulse detected. Going back in the garage to check opti connections, and reading up on this.

 

Checked the wiring/connection to the opti harness, all looks fine. Online the next step is replacing opti.....my opti doesn't have 50 miles on it, basically brand new.

Kind of strange I'm not getting any O2 fault codes, only code 36. Now what....hmm..

 

Did you clear the codes? Perhaps it's an old code.

What kind of opti is it?

 

It's a new MSD unit, the entire opti. Cleared codes, about to take it on a drive. I'm sure the codes will come back.

Here's the voltages I'm getting on the opti harness:

Engine running....
Pink/black wire .01v
Red/black wire 14.4v
Red wire 1.3v
Green/black wire 2.76v

 

Do you have the old opti? If so, swap out the optical sensor and disc from the old one to the new one and see what happens.

 

Some good work done today, and I figured out what could be the root of the problems here...maybe..

When I cleared the codes and took it for a test drive, it was fine until it got up to 160 degrees, then the idle started fluctuating just as before, the longer it ran, the worse the fluctuations. But it didn't set off my check engine light, and there was no codes.

Now as the engine is running all crazy by itself I'm looking at the engine dumbfounded again. I start touching/messing with the vacuum lines on the driver side intake manifold. I accidentally pulled out the pcv valve and the engine immediately smoothed out and ran and idled perfect. Hmmmm...checked the pcv, and hoses, all good. Put it back in the intake...terrible idle..now wtf? I researched online the vacuum routing and found my hoses where ran all wrong. Granted I was looking at a diagram from a 1995 lt1, but my 93 has all the same ports as a 95.

What's strange is its just started acting up this way, those vacuum lines haven't changed since 2008. Anyway, ran them all the way the diagram showed and am clearing the computer now. I did get the code 36 again once I pulled the pcv while it was running. Very strange. Will report later after I run it again.

 

Does this new msd vented opti have to be hooked correctly to vacuum for it to operate correctly? The vacuum hose harness that came with the opti is already dry rotted and cracks everywhere. I put a cap on it and pulled the hose off so there won't be a leak. From what the instructions said one end of the vented system goes to the intake, other end just an elbow on after the air filter. There are some check valves along the way, but wouldn't a vacuum hooked up to an open air system cause a vacuum leak? Or do the check valves stop it? Anyway pretty crap hoses from msd...thanks..

 

Very strange...reset the computer, started it, it immediately ran like crap, like normal, like I haven't been trying anything and everything to figure this out...rpms all over the place...no check engine light...until....

Once it ran like garbage all the way up to 160, the check engine light came on with the fans and the thing ran like a champ at the same time. Just went and drove it around, it runs fine with the check engine light on and both fans running....is my pcm gone haywire?

 

Your PCM went into maintenance mode. You really need to get a data log going.

 

Gosh I know it. I just hate to buy a $50 cable to plug it into a laptop, I won't even know what I'm looking at or what I should be seeing, if I have enough computer brains to get the program to work.

 

It's easy enough. Get the cable, it's worth every penny. Install the cable driver via the DVD the cable comes with. Download and install Scan9495.exe (google search for Gary Doug or Scan9495.exe) or $EE Hack (Google search for Steveo or $EE Hack). Connect cable to car and computer, open the program you installed and find the connected com port in that program and select it. Then click connect with the engine running and watch it record everything. Don't forget to save it before you close the program (it'll ask you to save anyway). Then compress that file to .zip (go to the folder the file was saved in, right click on the file you want to attach to your post, select "send to", then select "compressed zip folder"). Take that zip folder and attach it to your post. One of us gents will look it over and help you out and help you know what you are looking for.

This isn't something that is learned over night, but it's not overly complicated either. It's really not that bad to learn, just take your time and you'll get there.

 

You just inspired me...lol...I live on a military base and there is an auto hobby shop here, I'm going in tomorrow to see if they might have all the stuff I'd need. If not guess I'll have to buckle up and buy the cord/dvd. Thanks!

 

One thing I miss most about the military, auto hobby shops......

 

I know they have scan tools and what not, but not sure about data programs. I'm hoping so.

 

I would be utterly shocked if they had any OBD1 LT1 datalogging software as they are all custom.

 

Waiting on tax returns to afford data reading components. Keep messing with different things. This thing is running so rich, it set off my carbon monoxide detectors in my house, we have an attached garage, but damn. Still code 36, idle everywhere. Thinkin of pulling the connector on the IAC when the idle hits a normal rpm to see if I can drive it until my cash flow hits.

 

Another thing to add that I never mentioned before is I know my battery is on its last leg, it starts strong and charges like it should, but I know my battery is getting wore out. Orreilys battery test said it's bad, with no other info. Is this worth diving more in depth on? A load test perhaps? Could this possibly be the root of all issues?

 

What's the voltage with the engine running? The battery should have a very small effect with the engine on if the Alternator is working right. A super dead battery can cause some issues if it's sucking up all (or most) of the Amps the alternator can make, but I rarely see that happen. Easy way to check is to start the car, with the engine running disconnect the Negative cable off the battery. You'll likely notice no change or a small reduction in idle (normal) or idle tone (from a reduced load). The engine should keep running just fine with or without the battery disconnected.

 

It's around 14.5v while running. I didn't think this had much to do with it, but...I'm about to try and get the idle somewhat normal and pull the plug on the IAC, hope that'll make it driveable for a few more weeks.

 

This thing is running fine with the iac unplugged. Any issues I should be on the lookout for running it unplugged?