I have recently baught my 94 Z28 and am new to this forum so please forgive any ignorance.

I have done some searching around but thaught it would be better if I posted my particular problem.

I was getting the from what I see usuall 1 - 2k miss/stumble/hesitation but then ran very strong through the rest of the RPMs

so I changed the wires. nothing

cleaned the MAF - nothing

changed the MAP sensor - nothing

pulled the vacuum on the egr and plugged the solenoid- nothing

Then after driving the car most of the morning I get back into the car and start it and it has this terrible miss..kinda like a dead cylinder. out of no where. Tremendous loss of power. so then

Changed the spark plugs - nothing

unplugged the MAF so it would use the default table - nothing

checked fuel pressure - OK

any one have any suggestions. I would hate to buy an Opti and still have the problem

 

Seeing that the problem is going down hill and it seems like an ignition problem since your fuel pressure was good, I would have to vote for the opti. Also, since its a '94 its likely its up to about the end of its lifespan.

Aaron

 

low rpm miss is 9 times out of 10 the optispark...

do a search and you'll find tons of info on how to replace it.

for the cheapest price on a new one contact jason chromer or is it cromer?

do a search and you'll find his contact info as well

 

Also I scanned it and am getting no codes

 

change the coil and the wire first, cheaper than the opti, if that doesnt work its time for a new opti

 

who scanned it for you?

 

a buddy of mine has a shop and used a 'Snap-On' scanner...

 

Good call, this is a good reason to upgrade to a MSD Blaster coil. Even if it doesn't fix the problem its still nice to have and only costs about $35-40.

Aaron

 

I would spray some (cat approved) carb cleaner on that little wire in intake mass air sensor,and see if that helps,then do the coil wire.If the opti was going,it would be a horrible ride.Also see if the water pump is leaking down onto the opti.Everybody likes to blame the opti for a lot of stuff,when actually it's other issues.Do the cheap stuff first.My02

 

Thank you everyone for all of your replies....

I have solved the problem......plug wire 7 was touching the header and burnt through.....it was a new wire....replaced it...everything ok...

Now back to the good ole 1-2k stumble

 

Also check to make sure the manifold pressure sensor (on top of the engine)is sealed tightly.Also check the connector to it as well.The wires seem to go south with age.My02

 

I've seen a lot of complaints here about MSD coils not lasting very long on LT1s. I'd stick with the stocker.