LT1 rough idle, ticking, poping in exhaust

[evilbeef54]

cool it sound similar to a burt plug wire that i had on the 72 now that i think about it now i guess i just gotta hire a midget or small child to change them out for me

 

[MyBoTy]

Which LT engines - early or late? The late ones used an "optispark" that's notorious for problems.

 

[Air_Adam]

Which LT engines - early or late? The late ones used an "optispark" that's notorious for problems.

I assumed the '94 Z28 in his sig, which would be the late LT1.

 

[rscamaro73]

Which LT engines - early or late? The late ones used an "optispark" that's notorious for problems.

Best fix I've seen for those is an LS1 swap

On the other hand, the 96 opti's are vented, and that helps with spark scatter and helps pull the 'vapor buildup' out of the cap....of course when you put a distributor underneath a water up, you're asking for problems....

Plug wires are a PITA....best to get it in the air 18" or more so you can work....SAFELY....

Change the knock sensor to an LT4 unit if'n you haven't already.....

 

[evilbeef54]

Best fix I've seen for those is an LS1 swap

On the other hand, the 96 opti's are vented, and that helps with spark scatter and helps pull the 'vapor buildup' out of the cap....of course when you put a distributor underneath a water up, you're asking for problems....

Plug wires are a PITA....best to get it in the air 18" or more so you can work....SAFELY....

Change the knock sensor to an LT4 unit if'n you haven't already.....

yea i'll have to try to jack it up and check when i get home, which will be fun, the guy before me had it lowered and i can barely fix the floor jack under it again im new to all this computer stuff why would changing the knock sensor be a benifit

 

[MyBoTy]

Best fix I've seen for those is an LS1 swap

Man, I'm with you on that one! I watched several dyno tests a few days ago with an LS1 with ported heads and a street hydraulic roller. Best run was just over 530hp, friggin' insane for that size engine that still makes enough vacuum to run power accessories.

 

[rscamaro73]

Interwebz explaination....

The LT4 knock module was developed along with the 1996 Corvette LT4 engine. The specific problem was the noise generated by the Crane Gold 1.6 roller rockers (relabeled as GM parts) used in the LT4 engine. The noise of the rockers was being picked up by the stock knock sensor, and getting through the LT1 knock module, causing the PCM to retard the timing. This is a case of "false knock".

The LT4 KM is simply a different filter to eliminate the noise signature of the roller rockers from the knock sensor signal, preventing the PCM from retardnig the timing and losing power.

There is a general belief that somehow the LT4 KM also filters out other noises that may produce false knock, but no one has really proven this to be the case. I guess most people install is as a bit of cheap insurance.

The only way to tell if you need one it to put a scanner on the PCM, and look for signs of knock retard. If you don't have any knock retard, there is simply no way the LT4 KM will change anything. Even if you do have knock retard, you would have to prove it is "false", and then see if the LT4 KM happened to filter out the noise causing the false knock.

The knock module is in the PCM, the knock sensor is on the lower driver side of the block (usually).....

 

[evilbeef54]

ah ha okay well good to know thanks, since that brought up roller rockers, anyone have any suggestions on a good brand that are good quailty without throwing away extra $$

 

[rscamaro73]

'HONESTLY'.....you'll get more tech style help with guys that deal with them all the time, and really hop them up.

The LT4 'Hot Cam' setup has really been proven to be a complete 'bolt on in a weekend' deal if you have a couple friends and the tools to do it.

A few guys from here as well as some other Camaro/Firebird/F-bod boards have the hands on with these.

They're a great engine....and always have tons of low end Torque.....plus you can't beat the sound of the exhaust either

 

[Air_Adam]

www.camaroz28.com

They deal almost entirely with 4thgen cars, LT1 and LS1 - very knowledgeable guys there. I learned alot when I first got my LT1 car. I suggest checking their message boards.