OPTI SPARK ??'s

[Caveman]

so i put together a new engine....will go into details of internals later if requested...but i think i have an issue with timing...it feels like the distributer is missing a little bit...like firing way too early... its fine at high rpm and heavy throttle but under light loads and lower speeds...engine or vehicle...it feels as if a few of the cylinders are firing early causing little jolts. is the opti spark adjustable and if so how is it done? or is this even a problem thats un related to optispark? any help appreciated

[MP81]

Yeah...sounds like Mr. Optifail.

[Will]

OEM Opti isn't adjustable, but MSD's is. You should check the easy sensors before you go tear apart half your engine to change the Opti though. MAF, MAP, etc.

[my95z28]

check for any codes

[Caveman]

she's not throwing any codes at all...could a sensor be bad and that system still not throw a code? i figured it would...

[Will]

You can have a sensor that is technically functioning, giving signal and everything, but not reading the right signal. I had this problem with my MAP and my MAF.

[Phantom409]

The Opti can go bad and not throw a code at all

Here is a link so you can test the opti to make sure it's your problem.

http://www.mainstreamtopics.com/foru...p?showtopic=78

I would say if your timing was off it would be more than just a few cylinders, it would ba all of them and the car would run real bad.

[Will]

I don't know about that Kyle, mine was bad for almost a year before it really went and started missing all of the time. I didn't really notice that it wasn't running right for all that time until it was replaced.

[Phantom409]

I had a few go to pot, they can have many isues and everyone's seems to be a little different.

Make sure your plu wires are on good.

[lozanoa11]

[Caveman]

so i checked the opti system as far as power in and out of the unit as stated by the info phantom dug up for me...everything checks out fine... guess im on to the map sensor... this isnt a problem ive had with the old motor...she ran perfectly..but i put this one together toss her in...and now she's having issues...

[bmwmcars]

so i checked the opti system as far as power in and out of the unit as stated by the info phantom dug up for me...everything checks out fine... guess im on to the map sensor... this isnt a problem ive had with the old motor...she ran perfectly..but i put this one together toss her in...and now she's having issues...

i would check your plugs & wires, both for firing order and for cracks/grounding/burns. i have seen a number of lt1s stumble and crap down low and act "ok" up high and in every case it was wires or plugs.