money pit

Hey guys, first post. Ive been reading up on this but cant figure it out. I made a huge post about every litle detail, but I had a crappy wireless connection and it didnt go through.

Basically, I put a new MSD cap and rotor on after my opti was getting worse. Then replaced the clutch, took i

money pit

Sorry that was all messed up, my connection was really bad and it wouldnt go through all the way.

Anyways, put the new cap and rotor on, clutch in, and after breaking the clutch in it ran awesome. I did a small burnout for a freind, as I was about to accelerate after the tires stopped spinning, the car backfired, cut out, and threw the ses. Scanned it later and it was code 16 and 36, high and low res opti signal. Clear the codes and it fired right up, and ran fine. Sat at idle, revved it a little, ran fine. then after a couple minutes it threw the code again. Still had the scanner running so I cleared code 16 again, it came back instantly, this hapened 4 or 5 times till I shut if off and called it a night. Came back a couple days later, started it up fine with no codes present, backed out of the driveway, and as soon as I went to put it in first to take off up the street, it cut out, threw the code, but then I continued up the street. It was very sluggish, hesitating and surging up the street. Pretty hard to get any kind of decent speed. Then as it started to warm up it ran better, it got to the point it ran great, just had a code thrown. Parked it for 15 minutes or so, went to start it again, it fired but stalled right out, tried again and it just cranked. It acted as though it was trying to start as we cranked but just wouldnt fire up. Finally after cranking more and persuading it with gas she fired, the SEs was on, it was backfiring alot, and it wouldnt hold an idle. I limped it down the street back home, backfiring and cutting out the entire time. Put the car on stands and noticed on the underside of the opti, on the driver side the very lowest connection, the vacuum line had a tear in it. Replaced that, then noticed that a 4 prong connector underneath the oassenger side of the throttle body was cracked. Unplugged the plus, no start, plugged it back in, she fired, threw the code again, then seemed to run fine, just a bad throttle response. What is that connector? I checked the harness on the pass. side of the intake manifold and it checked out, I tried to look at all the connectors on the opti but couldnt see much today so I'll look again tomorrow. Any other suggestions guys? I seached and looked at everything thats I found to look at so far. I need to get this fixed so I can sell it, to many toys and I cant afford this fun one anymore.


Thanks for any help.

-edit- Also its a 94 6 speed, forgot to add.

shoebox

You have a bad opti or poor connection to it.

Greaseymec

I had a code 16 when my opti died. It's the opti code of death.

Mec

Injuneer

DTC 16 isn't uncommon to find in a "scan". It apparently can show up when the PCM has a problem finding the Opti low res pulse on startup. But if you clear it and it comes back frequently, its a sign of the problem Rob/Shoebox pointed out. When the PCM sets DTC 16, is also shuts down the fuel system, injectors and fuel pump. If the engine is running, DTC 16 is a "stored" code. If it won't start, its an "active" code.

Your mistake was replacing only the cap and rotor. If you don't find corrosion on the harness connector pins, you will need a complete new Opti.

Possibly the connector for the IAC motor on the plate on the bottom of the throttle body?

Shoebox has a labeled photo of the complete wiring harness:

http://shbox.com/1/harness.htm

contraststriker

I wanted to believe in my opti, I really did. I investigated every single possibility besides the opti, but ultimately code 16 told the tale. Sorry, but it's rarely wrong

money pit

So could I just replace the sensor now, or do I need to buy a whole new unit? Is there something I could buy so I cold keep this MSD cap and rotor, since its supposedly a little better than stock? Trying to keep this cheap, this is all thats holding me back from selling it, besides this the car runs flawless.

Dave89IROC

well, the GM opti comes complete, if you want, even though quite a few people say not too, you can get a opti from Autozone, it is just the opti, no cap/rotor, and it comes with a lifetime warranty last time I checked