Opti going out???
Le Mans Master
Joined: Oct 2004
Posts: 7,705
Likes: 485
From: Everett WA
C4 of Year Finalist (appearance mods) 2019
You're driving along under light load and it starts to feel like two cylinders are dropping off.
You put your foot to the floor at a stop sign and it revs great to about 5000 RPM and then starts to break up.
Hard to restart when engine is hot but starts up no problem when cold.
I don't think that they generally fail "snap" like that it usually the optical sensor getting covered (so that it doesn't sense) with oil or dirt or the high voltage circuits burning out over time... or the cap and rotor needing to be replaced.
You put your foot to the floor at a stop sign and it revs great to about 5000 RPM and then starts to break up.
Hard to restart when engine is hot but starts up no problem when cold.
I don't think that they generally fail "snap" like that it usually the optical sensor getting covered (so that it doesn't sense) with oil or dirt or the high voltage circuits burning out over time... or the cap and rotor needing to be replaced.
Burning Brakes
Joined: Feb 2013
Posts: 767
Likes: 95
From: Central Pennsylvania
Just replaced the Opti in my 92 this past spring. Problem started out when the car would just stop running. Gradually it took longer and longer to restart. Finally it wouldn’t start at all. Ran great before it died. Went the ICM and coil replacement route first. No luck. Bit the bullet and replaced the Opti. The one I pulled out was in for 2.5 years.
Advanced
Joined: Oct 2016
Posts: 74
Likes: 11
From: Bradenton Florida
2017 C4 of Year Finalist
Skyhawk50
just out of curiousty, what brand did you pull out, (that only lasted 2.5 years) and what did you put in.
Thanks
Woody
just out of curiousty, what brand did you pull out, (that only lasted 2.5 years) and what did you put in.
Thanks
Woody
Last edited by woody3882; Nov 1, 2017 at 11:20 AM.
Burning Brakes
Joined: Feb 2013
Posts: 767
Likes: 95
From: Central Pennsylvania
Racer
Joined: Sep 2011
Posts: 462
Likes: 30
From: Riverside California
My was running fine, but was idling to the point it felt like it would stall either hot or cold. Went from a slight miss to serious over a few months.
Currently running great with about 1200 miles on the new Petris opti.
Le Mans Master
Joined: May 2005
Posts: 7,300
Likes: 2,220
From: Central Maryland
Opti failures come in two distinct flavors:
High voltage (distributor) side of the unit misbehavior will act just like any other distributor that has carbon-tracking on the cap, etc. Misfiring, backfiring, afterfiring, etc.
Triggering (optical sensor) side of the unit misbehavior will trigger a code, either a high-resolution failure code, a low-resolution failure code, or both. Normally one or the other. A low-resolution failure should shut down the engine because the ECM will be unable to determine the coarse position of the camshaft. A high-resolution failure will not deprive the ECM of coarse camshaft position timing data, so it should still be able to run the engine. What will be lacking will be precision instantaneous camshaft position data, as well as shaft velocity and acceleration/deceleration data, so optimal (no pun intended) performance will be somewhat compromised.
Live well,
SJW
High voltage (distributor) side of the unit misbehavior will act just like any other distributor that has carbon-tracking on the cap, etc. Misfiring, backfiring, afterfiring, etc.
Triggering (optical sensor) side of the unit misbehavior will trigger a code, either a high-resolution failure code, a low-resolution failure code, or both. Normally one or the other. A low-resolution failure should shut down the engine because the ECM will be unable to determine the coarse position of the camshaft. A high-resolution failure will not deprive the ECM of coarse camshaft position timing data, so it should still be able to run the engine. What will be lacking will be precision instantaneous camshaft position data, as well as shaft velocity and acceleration/deceleration data, so optimal (no pun intended) performance will be somewhat compromised.
Live well,
SJW
