Cross

iTrader: (10)

Ok I am on my iPhone so forgive spelling etc.

This thread explains some sim issues I found while searching.
http://ltxtech.com/forums/showthread.php?t=7249

This is my direct information. I am at the shop testing now.
On the way here the car would do this still intermittently.
No set anything tach needle just would jump.

Main info (copy paste setup)
This sounds a lot like what I am going through today.

Up in Phoenix for a weekend trip. The Dynaspark was just rebuilt I ahve been really easy on it but I got on the course and of course I had fun lol.

Well I had to play with the panhard a little and I thought I heard a whine coming from the rear. Well I go to turn into my buddies house and i had to make a U-Turn. I have been on The interstate the whole time, drove up here no problems its got good oil pressure and its under 160 the whole time.
Anyway I turn and notice it starts stumbling around 3-35k.... Then goes away. I pull up to his house and Rev it no problem. I am concerned but pop the hood and everything looks good.

I go to leave and I do not even make it a block. I tried going above 3k and it freaks out the Tach is jumping around like a Midget on Crack. Then it dies. I had that Optispark sinking feeling but she fired right back up but now its worse its hesitating, jumping all over then smoothing out then jumping it does not die but it tries to even just sitting there idling.

I pull into the corner strip mall and I turn it off, start it back up its still doing it but it starts right up... I am lost. I do not think its an Opti like before but I am at a loss. I do not have a code reader for the 95 around me and I know nothing around here so buddy to the rescue... I hope its just the ICM.

Cross

iTrader: (10)

According to the tech2 (I think I am using this right).
6 codes
0016 low res pulse circuit. (dreaded opti....)
0018 injector circuit
0042 ignition control circuit grounded
0046 passkey
0047 KS Module Missing
0051 PCM PROM

robsquikz28

iTrader: (246)

here is some good reading for ya its straight from my alldata....especially for your no start problems and missing I have found it to be one of the below. This can and will cause all of those codes.

Reference ground.
This circuit is grounded in the ignition module and the computer; it makes sure the ground circuit has no voltage drop, which could affect vehicle performance. I have found an open in this circuit can cause a vehicle �no start� as well as a false code 42/E23.

EST.
This circuit triggers the ignition module. The computer does not know what the actual timing is, what it does know is when it gets a reference signal. It uses this reference signal as a base point and advances or retards the spark from that point. So, if on vehicles where the base timing is adjustable, and the base timing is set incorrectly, the spark curve will be off through its entire range by the amount that the base timing is misadjusted. An open or short to ground in this circuit will set the code and cause the engine to run on ignition module timing.

Why the computer flags this code.What we have here is a failure to communicate.� The ignition module and the computer are in constant communication when the engine is in operation. (Over 400 RPM.)With the computer telling the module the correct timing. If communication is lost or a circuit becomes infected with false signals (bad grounds, short to battery +, Electro Magnetic Interference {spark plug wires to close to circuit wiring}, oil contamination of the circuit connectors and wiring) then the computer will turn timing control back to the ignition module and flag the code.
Possible causes:� EST circuit open or grounded.
� Bypass circuit open or grounded.
� Reference Ground circuit open or shorted to battery� +.
� A bad computer to engine circuit ground.
� A defective ignition module.

� A defective computer.


If you are testing a vehicle for this code check the routing of the spark plug wires making sure they are not to close to the EST circuit(s) wiring. Check the connector terminals making sure they are not over-sized or oil contaminated. Check the entire wiring of the circuits for chaffing,
short(s) ground.

Cross

iTrader: (10)

Brand new Dynaspark, well just rebuilt got it back in August.

robsquikz28

iTrader: (246)

added more info for ya

Cross

iTrader: (10)

Thank you I have been on GM Connect trying to find information and the site is having issues it seems.

That gives me a lot to go off of and I think i know some of the ground wires its talking about.

Cross

iTrader: (10)

Just cleared the codes and moved the car around she revs all the way up but the tach started going nuts again after I let off the gas.

I checked the codes again and there is only one...
0016 Low Res. Pulse.

So a Just completely rebuilt Dynaspark leaves me stranded 150 Miles from my home. I am so tired of Opti's I could blow the whole god damn car up.

I am parting this thing out I am done with it.

robsquikz28

iTrader: (246)

Have you tried to replace your opti harness at all??? it can be bad or even check the wires going into every connector in the back of the pcm and make sure they are all in their designated spots and clicked in. Then check the main ground on the pass fenderwell and power side as well. Make sure they are not loose and see if there are any burnt wires indicating, shortage. Then check ur Icm/ coil and make sure they have a good contact, did you do a icm mod at all?

Cross

iTrader: (10)

No ICM Changes, the Harness from the Opti is built in on the Dynaspark.

I am going over the wiring now but I did not think anything else caused the Low Res Code but the Opti Failure.

Also its still not throwing the check engine light the Tech2 is just giving me the code for it... strange. I know it works I see it come on when I have the key on engine off.

Either way though Rob, your help is def. Above and Beyond I owe you a pitcher of beer some time. I can not thank you enough.

robsquikz28

iTrader: (246)

No problem at all man, also the harness may not be bad in the opti, but going to the opti harness may be bad...Yes the opti will throw that code only, but it can be the wiring goin to the opti or out of the pcm. You can trace those wires from the opti harness back and see if they are bad, burnt, pinched in between something or better yet schaffing on the frame or block. I would drive it around a bit and let it throw the code and then check it, you will have to do atleast 2 drive cycles for it set a ses light. I have family in AZ so maybe 1 day I will hit u up and we can chill!!!! But try all that before you ditch the beautiful car, you will regret it.

Cross

iTrader: (10)

I am checking all the wiring but it just seems myself and optis do not mix
three in less than 6 months

Cross

iTrader: (10)

All wiring is good. Seems my Passenger Valve Cover is Leaking now too... Brand New less than a week ago I had a feeling I should have used some RTV on it. Oh well not horrible to fix but there is always something.

So its new Opti Seal, New Opti/Dynaspark Rebuilt (I have no idea how long its going to take), Reseal Valve Cover. OH the FUN!

I'm sorry but I am thinking about grabbing a stock opti from a member making it run and demodding it while listing it for sale.

This is Opti #4 to go on next and thats just too much.