LT1 is acting up badly

[Fbody3400]

Driving today, this is what happened:

Started stuttering real bad around 10 mph, its like you can feel the pistons hitting actually. Felt like a really bad misfire.

No SES light

High idle (2500) in park

I tried to get it back to park and right before i was almost there it died.


So any ideas guys?

[loser]

Re: LT1 is acting up badly

how many miles? whats been replaced?

fuel filter? crank pos. sensor?

it only idle's high in park?

does it act up the whole RPM range? like, does it stutter from 0 to whatever?

[BEAST]

Re: LT1 is acting up badly

on lt1's the opti spark is a big problem....there is ways to find out if its out or not try going to z28.com they have a article on it.....check you coil and icm then check your opti and see what you get.

[97rs4life]

Re: LT1 is acting up badly

on lt1's the opti spark is a big problem....there is ways to find out if its out or not try going to z28.com they have a article on it.....check you coil and icm then check your opti and see what you get.

that was my first thought, was that stupid opti unit on those lt1's that people have so much trouble with.

[BLLDOGG]

Re: LT1 is acting up badly

sure was. Opti FTL!!!

[vanbibber]

Re: LT1 is acting up badly

well...

the funny thing with the opti is, sometimes the ses comes on, sometimes not. sounds like what mine was doing sort of, but not quite.

check the vaccume lines first before anything on the drivers side. make sure no cracks or loose ones. best way of knowing the opti is toast...

high rpm power is gone, stutters bad at low rpms, ses light MIGHT come on(might not like i said) when breaking the car with feel like you have a huge *** cam and the car will kinda jerk and feel like its about to die.

and since it died on you, theres a good chance thats it. dont drive it!!! opti going bad will throw all sorts of things out of wack trust me.

[Vanquish]

Re: LT1 is acting up badly

I would definately check your Opti-Spark, or possibly your FPS and the hose that runs too it for any tears, crack or just plain wear on it.

Then, if that all checks out fine, do a tune up of cleaning the air filter, fuel filter, and anything else to do with the air or fuel.

But, my money is going to be on your Opti-Spark or your FPS(Fuel Pressure Regulator)or the hose that runs to it.

[vanbibber]

Re: LT1 is acting up badly

heh, you really cant check the opti without pulling damn near the front of the motor off.

[Vanquish]

Re: LT1 is acting up badly

heh, you really cant check the opti without pulling damn near the front of the motor off.

Oh, well I was unaware of that. I'm not familiar with the LT1 engine style very much, so sorry for the bad advice.

3.8's are my specialty:tup: FTW

[vanbibber]

Re: LT1 is acting up badly

feel lucky. lt1s make you want to jump off a cliff. opti uninstall/install is a good 6 hour job the first time.

[Vanquish]

Re: LT1 is acting up badly

I've always read about reviews and writeups in magazines and online about the Opti-Spark being the worst designed feature that GM ever made.

That's what has inspired me never to purchase one.

In one of the reviews I read that the guy messed his Opti up just by washing his car and some water got down under his hood and wet the Opti. If that were the case, then I would be very scared to drive it while it's raining.

[vanbibber]

Re: LT1 is acting up badly

yep. optis and water dont mix. i hate washing my car because of it. gotta be careful. i avoid at all costs driving in the rain because of it. the vented opti's are much better because they let moisture out instead of the older ones that arent vented and the moisture has no way out, which wreaks havoc on the unit.

its not that its bad, its just placed in the worst spot possible. it sits on the front of the motor in between the waterpump and the timing chain. if the water pump goes, the opti is toast 99% of the time.