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I need to correct myself on this part. “All” vented opti’s from the factory regardless of what year make or model had the timing cover with the larger distributor seal hole.
I stand firm that vented opti first showed up in the 94 B body cars. Corvette and F body cars began in 95.
Okay, so it seems safe to say that all the sensors for the non-vented optis are the same and will interchange, and the same is true for the sensors from all vented optis. IOW, if you have a vented opti and the sensor died, then you should be able to replace it with the sensor from any other vented opti. The OP has a non-vented opti, and the sensor from any other non-vented opti should work in it.
Yeah, I believe I've heard before that B-bodies got the vented setup in 94. I have no trouble believing that.
Anyway here’s a 94 Fleetwood LT1 that just showed up in a local Baltimore junkyard. In addition to getting vented opti and other related components, these cars are also good donors for the 8051 OBD1 LT1 PCM’s. They work on all LT1 cars including those who wish to step down from OBD2. I’d run up and snag this one but I already have a couple spares here in my garage. Notice in the pic below of this 94 Fleetwood engine. See the opti vacuum line vent connected to the intake bellows?
They’re also good donors for the various sensors, ICM and related components. Good opportunity to get cheap spares here. Many you can still find the functional OEM stuff still there
They’re also good donors for the various sensors, ICM and related components. Good opportunity to get cheap spares here. Many you can still find the functional OEM stuff still there
The OE water pump is worth snagging too! The replacement ones you can buy now are junk, including "AC Delco" branded ones.
Not any other LT1 car. The 96 Corvette and the 96 B body LT1’s are OBD2. The 96-97 F body cars with LT1 are also OBD2. The sensor in those optis are different than 95 and earlier OBD1 LT1’s.
good point, also there’s two kind of optispark
spline drive and pin drive depending on your car years
Side note, since the water pump was replaced when the PO replaced the Optispark, I plan on replacing the gaskets, but should I replace the seals on the engine and water pump seal? From what I can tell there is a seal on the shaft coming out of the engine into the optispark and one in the shaft going into the water pump. No I don't think I need to replace the water pump......
As far as the fuel system contaminants, I decided I would pull the pump and look in the tank. If it is dirty, I would drain and clean....thoughts?
I’ve been in the same boat I’ve replace my opti with a Petris last week and I do replace both oil seals in the timing cover while I was there for peace of mind this whole job is a pita and I don’t want to get there again
If you decided to put new seal I have buy the special tool to install the one for the water pump and it’s worth it if you one mine send me a PM I’ll let it go for cheap Good luck
Last edited by captain vette; Feb 16, 2022 at 12:32 PM.
Here's an article about converting a non vented opti to a vented opti. I did this for a 94 LT1 we have in a 79 Malibu wagon. I did not use the exact process as in the article but used it as a guide. Instead of modifying the cap I just used a vented cap from a later model LT1. For the mod tho the distributor body, the article shows using a series of vacuum t's to connect to the three drain holes. Instead I just plugged two of the holes and used a vacuum nipple on one hole. Anyway, here the article.
Day one breakdown…..came apart nicely. PO installed a vented opti but did not install the hose.🤦🏻♂️ So I’m guessing my opti is shot because of this. Nonetheless, I have the Petris in hand and should have it back on tomorrow. My question is, I drained the coolant and the color was not orange, nor was it green but more like Carmel color…..
should I do a flush and change the thermostat? I’ve read the orange and green don’t mix and can cause issues.
A true vented opti has two vacuum line connections. One in the cap (plastic) and one in the distributor body (metal). Does your old one have both? It’s possible to put a vented style cap on a non vented distributor body.
What does the optical sensor look like? Can you post a picture of it?
On your coolant question, they now make green colored coolant which is designed to mix with all other types of coolant, regardless of color. Perhaps the PO did that. One thing for sure is if non compatible green coolant had been mixed with Dexcool, the result would be nasty brown sludge wreaking havoc on the cooling system.
Looks like the PO skipped the step associated with completing the vented process! Lol 3 small holes on bottom of the aluminum part and the vent tube on the cap screams “vented” but nothing connected up soooooo seems more like it screams “water/contaminants entry point”
Looks like the PO skipped the step associated with completing the vented process! Lol 3 small holes on bottom of the aluminum part and the vent tube on the cap screams “vented” but nothing connected up soooooo seems more like it screams “water/contaminants entry point”
That is a vented style cap on a non vented style distributor body. The non vented units had those three “drain holes”
Well finished everything up. Started up, running water through the system to flush. Now my “miss” is worse. And I have a new rich smoke out the exhaust.
still on jack stands, will take it for a run tomorrow, but I’m a little concerned. A few small backfires or pops.
Does this need to run before ECM and Optispark start to work in unison or do I have a different issue?
this one was painful. No codes, yet.
Well finished everything up. Started up, running water through the system to flush. Now my “miss” is worse. And I have a new rich smoke out the exhaust.
still on jack stands, will take it for a run tomorrow, but I’m a little concerned. A few small backfires or pops.
Does this need to run before ECM and Optispark start to work in unison or do I have a different issue?
this one was painful. No codes, yet.
Sounds like your coolant temp sensor by the water pump didn't get plugged back in, or maybe it got broken during the other work you did. This is not the one in the cylinder head (which does nothing but run the crappy "analog" temp gauge). It's the one next to the round water pump face at about 4 or 5 o'clock as you look at the water pump from the front of the car. It sends info to the digital gauge in the DIC, but more importantly it give the ECM the coolant temp info so it can properly manage the fuel and spark parameters. If it's bad or unplugged, it can cause this kind of symptom.
Sounds like your coolant temp sensor by the water pump didn't get plugged back in, or maybe it got broken during the other work you did. This is not the one in the cylinder head (which does nothing but run the crappy "analog" temp gauge). It's the one next to the round water pump face at about 4 or 5 o'clock as you look at the water pump from the front of the car. It sends info to the digital gauge in the DIC, but more importantly it give the ECM the coolant temp info so it can properly manage the fuel and spark parameters. If it's bad or unplugged, it can cause this kind of symptom.
so funny thing about the sensor, I broke the sensor a few weeks back while loosening the belt to get the alternator off, so I had to install a new one. Checked the wiring and made sure everything was plugged back in.
I feel like I am becoming a parts replacement mechanic and I don’t want to go down that path. Any good advice for testing/checking for why this is happening?
it is not a “rhythmic” miss……it’s more of a Run run run Miss run miss run run miss miss run run miss run run run ( best way I could put the miss into words) lol
so funny thing about the sensor, I broke the sensor a few weeks back while loosening the belt to get the alternator off, so I had to install a new one. Checked the wiring and made sure everything was plugged back in.
I feel like I am becoming a parts replacement mechanic and I don’t want to go down that path. Any good advice for testing/checking for why this is happening?
it is not a “rhythmic” miss……it’s more of a Run run run Miss run miss run run miss miss run run miss run run run ( best way I could put the miss into words) lol
The Engine Coolant Temp sensor (ECT), is a voltage-varying device and the ECM figures the coolant temp based on the voltage it sees from the ECT. 5V is cold (like cold start) and 0V is high temp. So if it's working, you should see it go from "low" on the digital readout and start climbing soon after a cold start. If it doesn't climb, the ECT is bad. It's not at all hard to believe you got a bad sensor out of the box. Somewhere in something called "service category specifications" there is a list of resistance values relative to temps that you could test with a multimeter and a pot of water on a stove top or whatever. I don't know where to find that. It's not in the Factory Service Manual. But the digital temp readout should give you the same info.
You guys are awesome! Thanks MathewMiller for all the help. Good news I figured it out and I can't even bring myself to share what the issue was. Lets just say it was clearly an "I.D.10-T" error.....Note to file, ALWAYS check and double check your wires when you land them on the Optispark. They are very easy to cross up..... She's running the way she should, now. Flushed the coolant about 6 times to get all the gunk out and filled it back up with green coolant. Ready to go cruising and enjoy my labor....
