squarehead

My car's engine quit running while I was driving home last night. I saw the check engine light come on and I put my foot on the clutch and the RPM went to zero. After coasting to a stop I tried restarting it but nothing.

This morning I towed it the last quarter mile to my house and shop (yes it could have been worse!) and connected my scan tool to read:

code 16: Ign system problem loss of low res pulse signal

This is not the first time the car has quit in the same way, and the last time it was the optispark. I have a new GM optispark unit that I bought just to have ready and I think it is time to install it.


Thanks for any advise!

Injuneer

Clear the code (pull "PCM BAT" fuse - underhood box - for 30 seconds), try and start it and see if DTC 16 comes back. If it does, it's the Opti. The SES light does not come on for that code. Do you have any other codes?

squarehead

There were no other codes.

I cleared the code using your PCM fuse removal trick. I confirmed that the code was in fact gone, then tried to restart the car. When I then rechecked the scan tool there it was again code 16 : Ign system problem

I will change the opti and let you know when it is done.

Thanks Fred!!!!

Chimera96

OP

while the opti can fail electronically, when you remove the opti confirm the rotor screws did not come out causing the rotor to spin

If after removing the cap of existing opti you see signs of oil or coolant contamination inside, you will need to resolve those sources. If you do find fluid contamination, it is recommended you confirm the function of opti vent harness as the orifices in the blue/white check valves can clog easily.

The FelPro TC gasket/seal kit will have everything in it to do the swap if you do need TC seals

bw_hunter

It is advisable to pull the cover on the brand new opti and apply red loctite to the rotor screws. It's easy and can save a whole lot of headache later on....

Injuneer

I have heard that the AC Delco units now have a seal on them, and breaking the seal voids the warranty.

bw_hunter

Thanks Injuneer for the update. The one I just bought as a spare didn't have a seal but may have been an old stock item....

squarehead

I just wanted to report complete success with the repair and that I am back on the road!

I got the job done on Wednesday evening but then got sucked into the preparations for a Thanksgiving party so I am posting this later. It took me about three hours to remove the opti on Tuesday evening and another three hours to install the new unit after work the next day.

I missed the post from bw hunter about the rotor check and I did not open the unit to double check the fasteners; I hope the manufacturer did the job well. The part I used was a Delphi OEM replacement part so we will see how that works. I considered removing the cap so I could twist the rotor/shaft for alignment onto the distributor drive but I got lucky and with a careful eyeballing of the slot I got it to slip into place on the third try. The fasteners holding the cap onto the body of the unit were a torx socket design and I suspected that the design was intended to keep dumbkoffen like me out of the inside so I figured if I could get the unit installed without opening it that would be better.

The failed opti spark I removed was a Summit Racing house brand and I do not recommend their use. This was the second of their opti's I had used and I checked my records and the first failed after 23K miles and the second failed after 24K miles. It was my research here at Camaroz28.com that led me to buy the OEM quality unit but only after I had already installed the second Summit unit a couple years ago. I look forward to a longer life from the OEM unit!

Thanks to chimera96 advise above I changed the distributor drive shaft seal and water pump gaskets following the tech advice from other threads here. I used the Felpro TCS45956 seal kit and having the part number was a big help as my local Napa guys were having trouble finding the information.

Bottom line is thanks to all the good posts and help from Camaroz28.com my car is back in service with minimal cost and delay!

moparman

The Delphi and AC Delco units appear to be the only reliable optis. However, I have noticed, checking around various parts outlets, there appear to be no new AC Delco optis available. Only remans.

Chimera96

unless somewhere you find old stock original AC Delco that "brand" is now reman

The Delphi is a "new" unit. At least the one I bought several years ago from thepartslady.com is

Injuneer

thepartsladi went out of business in 2010.

Chimera96

yeah I know. I was just saying my Delphi was a new unit but I bought it years ago so I don't know if the "Delphi" opti sold today is new or reman. I think they are new vs reman still unless you know otherwise Fred

Injuneer

Don't know.... but the AC Delco only switched to reman a couple years ago.

timnfxr

Rockauto sells the DELPHI (P/N CZ20003) new, but their quantities are usually limited. Although the price has gone up since I bought mine 2 1/2 years ago, it's still cheaper than the AC Delco reman.