Scott, I have a question...

[min301]

97 camaro Z-28/SS, owner added LT-4 hot cam, now has recurring
cylinder missfire codes(random).
Is this caused by the lopey cam, or is there changes to the tuning
that can aleviate this?

[dieselgeek]

Re: Scott, I have a question...

97 camaro Z-28/SS, owner added LT-4 hot cam, now has recurring
cylinder missfire codes(random).
Is this caused by the lopey cam, or is there changes to the tuning
that can aleviate this?

That's a pretty common swap. He would be best to check with the LT1 crowd/forums and see if they typically just remove the check for misfire in the stock tuning? or if they recommend VE table changes, etc.

I know the hot cam is not that crazy of a cam. He may have an intake leak in that cylinder or something like that. Make sure it's actually firing on that cylinder (look at the plug, etc.)

[shaun callaway]

Re: Scott, I have a question...

min i thought you were a god at this stuff....hmmm....maybe not

have you tried the basic checking plugs and wires. usually this is where it is or the ignition module itself. i have done a couple of these cam swaps for friends and never seen this pop up.

back to the basics......

[shaun callaway]

Re: Scott, I have a question...

what is the code number for this vehicle?


have you checked the resistance on the plug wires? are the plugs gapped correctly? do any of them look fouled?


the resistance should be something like 10,000 ohms


does this motor have a distributor (sorry im not chevy savy)

[TheSilverBuick]

Re: Scott, I have a question...

Random cylinder mis-fire codes are the worse. I've seen the crank trigger sensor cause that for what that's worth. But checking the basic's on the ignition system is a good place to start. Is there a chance it's a weak fuel pump causing a mis-fire when there is an electrical spike from the brake lights, A/C Clutch activation, etc?

[shaun callaway]

Re: Scott, I have a question...

ok so i went and looked at our 94 and 98 and they are coil over plug so i will retract my "is there a distributor question"

i would go with a simple plug and wire change or see if you can narrow it down to specific cylinders.

sometimes you can erase the code and see if it will come back on and it may be more specific then you can diagnose the coils but first do a plug and wire change.

maybe he got shitty gas.

[CTX-SLPR]

Re: Scott, I have a question...

97 Camaro is an LT1 with the optispark MkII. The wires run under the headers so I'd check to see if they are fried. Can also check the Opti to see if it's in good shape since they do have a bit of a reputation for failure but the MkII is definately better.

[min301]

Re: Scott, I have a question...

min i thought you were a god at this stuff....hmmm....maybe not

have you tried the basic checking plugs and wires. usually this is where it is or the ignition module itself. i have done a couple of these cam swaps for friends and never seen this pop up.

back to the basics......

It's my new coworkers car, I haven't looked at it.

[min301]

Re: Scott, I have a question...

Cap and rotor, wires, and plugs are all new.

[shaun callaway]

Re: Scott, I have a question...

so the optispark crap is good?

[min301]

Re: Scott, I have a question...

Yes, according to him, it's all been replaced. All GM parts.

[shaun callaway]

Re: Scott, I have a question...

hmmmmmm

well you could check for a leak somehwere but i am not confident to say that is what it is.

if it was me i would erase the codes and see how long it takes to come back and in what fashion they com back in. remember a sparkplug gapped wrong on this car could cause it aswell. stupid i know but it is a gm. hahaha

maybe the ignition module this could cause it

[CM325]

Re: Scott, I have a question...

I had a buddy who had an IROC with the same similar problem. Even though he replaced the cap,rotor,etc...
It turned out to be the optic pick up under the rotor. It looked like the thermopaste had broke down and let the sesnsor burn up. Once that was replaced he was good for a month or so till the anti theft in the key went, so that led to chasing the circut and place a comparable resistor in line to fool it.
Anyway that's my .02
Good luck, I absolutely hate electrical grimlens.
CM

[shaun callaway]

Re: Scott, I have a question...

Good luck, I absolutely hate electrical grimlens.
CM

i like them because they make you use your brain, something most people dont do anymore.

[min301]

Re: Scott, I have a question...

I don't mind, it keeps me from getting into trouble. ;)