derekguzz

94, 6spd, no spark, I installed

new water pump
new opti spark
new wires
new plugs
NEW coil

the coil was the last thing I added and after I put it in, I tried to start it and it fired for about 3 seconds then died and won't start. My battery was dead so I hooked it to the jumper. Maybe I have to have a full battery I dont know. I am going to check codes right now and see whats going on. I will check fuses again for the 10th time. I am confused and MAD !! ha

surfer92

Was it running before install?

Recheck wires, 9 times out of ten, you either crossed 2 or more wires or boots are not on all the way.

Why did you change everything?

Mark85Vett

Sounds like you're throwing parts at it...that gets expensive!
Spend a little more money and get an FSM...it'll pay for itself!

derekguzz

I have an FSM, It was running great, then wouldnt start, I had it towed to a place and they said water pump leaked onto distributer and wires and plugs need to be replaced as well ($ 2,200) So I had it towed to my house and I replaced what they said.

Al Borman

First thing you need to address is your battery. The PCM and all associated electronics depend on a reliable and stable voltage source.

Second, check for any stored error codes. You had 3 seconds of glory before it crapped out. See if the offending component threw an error code. When you installed new coil, did you loosen or remove ICM from the heat sink ?? The ICM needs to have a thin layer of thermal compound to reliably transfer the heat generated from ICM to the alumimum bladed heat sink.

Also check your fuel pressure. Put an FP gauge on there and turn ign. to "On" position. Make sure there is approx. 40 psi at the rail (please double check this, but I think '94 is spec'ed at 42psi).

Double check your Opti connections and coil connection.

<<AIR>> <<SPARK>> <<FUEL>> .... You lost either spark or Fuel ..... air is a no brainer as long as your IAC is working.

derekguzz

I went to auto zone and got a piece of metal that a guy told me to put in where a obd1 would go and it would flash my engine light and correspond to the codes, Well the damn thing doesnt fit in the two holes. Its too big, So I can't check codes today. I did take apart my icm and didn't know about the thing coating between the icm and housing. I think there was a rubber coating of some sort. This si crazy. I have never been close to the engine only to change oil and flush my coolant. HA this is a big step for me. I am surprised I switched out my opti and water pump. So I gues I wont touch anything till I check codes.

surfer92

Use a paper clip to get codes.
Did you have the coil checked?
Did you take the cover off the old opti and check for coolant or corrosion?
did you check the old WP for leaks?
Did you check the ICM?

ICM and coil can be checked by parts store and when a coil or ICM goes bad, it will not throw a code.

Did you do a search here?
This problem has happened a million times.
Did you check the opti, coil and ICM harnesses for broken wires or insulation?

markKlein

Make sure you didn't mis-route any of the plug wires. It is easy to do.

Al Borman

Forget autozone. Just get a small piece of wire and short pin#4 and pin#12 shown below. Then turn ignition "On" but don't start engine. Codes will display where the digital gas gauge is. "C12" is the first code you will see which means start sending serial data. Anyway, write down any codes and report here if you don't know what they mean. My '94 has the 16 pin ALDL connector below. If by chance you have the 12 pin connector, you will short PinA and PinB together.



Since you seem new to the LT1, let's re-visit your Opti install. Are you aware that the Opti spark drive gear is splined and fits ONLY 1 way on the front of the cam. If you did not line up the spline correctly, your engine will not start. I know you said it ran for 3 seconds, but let's just make sure you installed it properly. Did you buy an AC Delco OEM Opti or an aftermakrket. You may not want to hear this, but it is not unheard of that some new Opti's are duds right out of the box.... If this is the case, when you get your error codes, there are several error codes related to the Optispark. So get the error codes. It only takes a few minutes and a piece of wire.

Lastly, I hope you did not wipe off the grease from the ICM and heatsink when you had it disassembled. The ICM will burn out in no time if this heat transfer agent is not there.

surfer92

AL, those are for F bodies and will not work on vettes.
Jump A and G with a paper clip, turn key to ON position, but do not start.

surfer92

Forgot, have you checked the fuel pressure?
Did you check for spark at the plugs?

derekguzz

I just checked fuel pressure and I am at 40. I did not match up the gear tooths for the opti spark, WHOOPS. Should I go back and fix that? I will check codes RIGHT NOW...be right back

derekguzz

ok checked codes and first thing I saw was C12, then under that I saw the number 1, then C 12 was gone then all I saw next was the number 4, then 9 then A, then 1.0 and it just stayed at 1.0 and didnt do anything for 2 mins then I took the keys out. Whats going on?

derekguzz

when I put in my new opti I had no idea about the slinned drive being keyed, but it fight right in and I bolted it up. Like the locking lug nuts on my truck, the key only works one way. Is that the case with the opti being installed? Like could I have put it in right if it fit, or is there a chance I got it in but still didnt line up the key right? ha

derekguzz

DONT LAUGH...but, is there another chance my car wont start because when I took my coil and ICM out I cleaned my ICM with degreeeser and water? it was dirty, I didnt soak the connecter part. But I gues the back of it shouldnt have been touched huh? HAHA

Al Borman

Ok, this is normal. If you did not see any history codes like "H64" then you do not have any error codes stored. I am assuming you have a standard LT1 engine VIN P (8th digit of your VIN reading Left to Right). Here is a listing of the error codes that are possable. An "H36" would be an Opti error, for example.

The numbers you see, 1 4 9 and A are different modules. If you saw something like:

C12 (this just indicates start of error code dump, you will always see this)
1 ---
4 ---
9 ---
A ---

Then there are no History error codes present. (Caveat - if you had a dead battery, or disconnected the ground terminal, this would have cleared your error codes)

http://www.troublecodes.net/GM/94_57P.shtml

Al Borman

OK, I am taking these questions 1 at a time. Yes your Opti is absolutely splinned or "Keyed" as some like to call it. The chances of you getting it installed the first time, with the splines aligned are very very thin. It usually takes a few minor turns to align the Spline in the driveshaft to the key in the cam shaft. Remember both the Opti side and front of your cam is splined. I have done a lot of these installs, and the easiest way is to insert the splinned shaft into the Opti first. Then get a flashlight, stick your head down in front of the CAM as best you can, and locate the keyed spline inside the CAM. Then turn the drive shaft in the Opti to match CAM position.....ballpark stuff. Then insert the Opti and splined drive into CAM. When you get it aligned right, it should slide right into the CAM, requiring no force. It is possable to have a mis-aligned spline and think you have it in correctly. Correct is when the splines are aligned exactly, and the Opti mates up flush to the front of the engine. It usually taked me 4 or 5 times before I get it in correctly. If you got yours in correctly while not knowing about the keyed spline, then you are EXTREMELY lucky...

derekguzz

If I even wired my wires to the plugs wrong it would stil fire each time right? It might run bad but it would fire...? why did my car start after a fresh coil but not a freah ICM? then die then not start at all? If my ICM is bad, is this a reason for not lighting up?

Al Borman

I'm not laughing, just trying to get you on the road again. No questions are stupid....only the unasked questions are !!!

If you did not remove the ICM from the aluminum heat sink that it is mounted to, then you should be OK. But you should have just cleaned it as best you can with a dry rag. If you just replaced the coil, then you really wouldn't have a reason to remove the ICM from the heat sink.... I think you are OK here...

OK, here's what I think we know:
1) your fuel pressure is good.
2) Optispark may or may not be correctly installed.
3) ICM may or may not be good, but probably wasn't damaged by cleaning

Next, and other folks have said it to......
You need to check for spark. Pull a plug that is easy to get to, ground the cathode against iron part of engine block, crank and look for spark jump.

1)If you do have a spark, and the engine is not starting, chances are the Opti is not aligned correctly so the timing would be completely wrong.

2) If no spark, time to back trace. Check coil for spark.

I'm getting tired of typing. When you installed the Opti, did it sort of snap right into place and the unit was completely flush with the front of the engine, or did you have to torque down the 3 Opti attaching screws to get it flush with the front of the engine ?????

Al Borman

Kind of depends on how many wires may have been crossed. Hve you double checked your Opti to spark plu wiring ?


How long did the car run before it quit ?? For the short time that the engine did run, did it run smoothly or was it rough and unstable ?????