Manbearpig

iTrader: (1)

So I picked up a 94 LT1 Formula last week

Ran like a raped dead horse
Replaced the opti and it idled good again

buuuuuuuuuuuuuuuuuuuuut

Everytime I take it out for a test drive it will start to stutter and die on me
Throws code 16 for low resolution

I know when that code gets thrown the pcm will cut fuel

I'm loosing my mind.

I'm not replacing that opti again

FFFFFFFFFFFFFFFFFFUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU UUUUUUUUUUUUU

Alex94TAGT

What brand/type of Optispark replacement did you use -- new, refurbished, aftermarket? Ensure that the waterpump isn't leaking on the new unit.

First things first, check the wiring harness.

If you have a digital multimeter with continuity test, you can check the wiring all the way from the optispark to the "Black" PCM connector. I found a bad pin on my intake manifold optispark connector that way. Helps if you use alligator clips + a paperclip/needle to probe the electrical terminals.

There are four wires:
1. Optispark Red/Black wire --> Pin 2 on black PCM connector
2. Optispark Pink/Black wire (Mine actually looks Orange/Black from fading) --> Pin 3 on black PCM connector
3. Optispark solid Red wire --> Pin 14 on black PCM connector
4. Optispark Purple/White wire --> Pin 20 on black PCM connector
That's what I have written down, anyway. I should probably double-check.

Clean out the electrical terminals with electronics parts cleaner (brake parts cleaner or isopropyl alcohol will suffice). I always apply dielectric grease on automotive electrical connectors.

Manbearpig

iTrader: (1)

Company says their units are new

Unit even looked new

I'm going out on a limb and saying it's refurbished though.

95mysticta

iTrader: (4)

Code 16 is either bad opti harness or opti itself. Check the voltage readings out of the harness first and if they are good its the opti. Simplest way to check.

DisasterFormula

iTrader: (1)

Companies spew bullspit all the time. What name is the company? For example, CMS makes great optis at times, but there for a while you had a 50/50 chance of a DOA and even still there are DOAs from them. MSDs can last 5 years or 3 months. Cardone will give you a good new one every once in a blue moon (I was one of those moons lol).

Manbearpig

iTrader: (1)

Richporter Technology?

Lol it was all my local parts story had in stock

I do have an acdelco unit on order though

95mysticta

iTrader: (4)

Did you do the voltage tests on the opti harness to see if they were good before assuming its the opti? I would sure hate to replace an opti to have the same problems as before when it could of been as easy a cheap 15$ harness.

Manbearpig

iTrader: (1)

Before buying either optis nope

Just did the continuity test and Im not pulling anything from the pcm pin



Will still feel better with a new delco unit in though

Manbearpig

iTrader: (1)

Anything else inbetween the manifold harness and the pcm?

The red/black wire will see nothing, then occasionally look normal then go back to seeing nothing

This can explain my random code 16s

95mysticta

iTrader: (4)

Optispark Harness
A = ~5vdc
B = ~5vdc
C = ~12vdc (or your system voltage)
D = ~0 - 0.2
ohms ground

Those are the readings you need to look for at the terminals off the opti harness going into the opti.

Manbearpig

iTrader: (1)

Okay my dumbass had the pink/black wire confused with the red/black

DisasterFormula

iTrader: (1)

shbox.com is your best friend for an LT1 car.

Manbearpig

iTrader: (1)

Delco unit comes in today and will be going in tonight

Car is already stripped ready for it to go in

Manbearpig

iTrader: (1)

Got the delco unit in

on the first start

Its running like absolute **** and sounds like its knocking terribly on the driver side

Engine smells like its been flooding up since I bought the thing

New plugs/wires went into it during the new opti install

It isn't possible to install these 180° off is it?

95mysticta

iTrader: (4)

Did you even do the voltage checks on the opti harness before just assuming it was the opti? If you were getting the correct voltages at the harness it should fire if not then its the harness and or PCM.

http://www.mifbody.com/DTCs/DTC%2016.jpg
http://www.mifbody.com/DTCs/DTC%2016_2.jpg

EDIT: Did you install it in the right slot of the opti drive? Common overlooked mistake that does happen.

Manbearpig

iTrader: (1)

Opti is installed right

I just found another issue

Have a leaky/stuck injector

Oil had about 3 qts of fuel in it

Not even exaggerating there



This car is a nightmare