Try replacing all of your wires. You probably have one arching that you don't know about.

Try accels universal wire kit from advance or autozone. @ $45. Thats what I have and it took car of my problem.

Just remember, you have to use the ends of your stock wires for the opti side, because it doesn't come with the accel kit. Take your boots and ends off, then put them on the accel wires. Remember you have to cut these wires, skin the ends off using regular wire strippers, and then bend the electrode back while you crimp the stock end onto the wire. Slide the boot over the end and stick it in the opti spark.

D Moss

 

Most arching wires may not show themselves until you're riding down the road when you're in the car and can't be looking under the hood.

i.e....taking off from start, reapplying gas when coasting, and trying to hold a steady speed at low rpms, and also really high RPMs 5000+.

D Moss

 

I found out what was causing it in my car

It turns out that the previous owner did a 7/8 spark plug job and thus I had one cracked plug. I also had 2 possibly arching wires. (you could see the white insulation at a certain spot.)

For those doing plug wires: I just bought one set of prefit wires, and them bought some single wires (long ones) That way when you are doing the passenger side, you can just reroute any wire that gives you trouble. I used zip ties to secure them. Forget about the stock looms.

of course, this is after an opti change. The opti change DID help, but it didn't solve it completely. The bearing on the opti was shot. Before the opti change, my car would rev itself up on its own occasionally. It would miss all of the time, hot or cold. After the opti, it would run fine until warm, and then start missing under load/ at idle. The idle would fluctuate a little, but it stopped the ghost revving.

blackdroptopta --- I hate when you think you have fixed it, and then it comes back. That is the worst! Make sure to check all of your plug wires.....you may have just burned another.

edit: EASY WAY TO GET TO #8 plug. The one all the way back on the passenger side. For M6 cars with stock manifolds.


Jack the car up. Lie underneath the car with your head under the trans, feet at the front of the car. Look up in between the Y pipe for the 02 sensor wiring. The plug is around there somehwere. You might have to feel for it a bit, but there will be plenty of clearance. Actually it was one of the easiest ones to get, once you have the right angle. No need to take off the starter. Hope that helps.

 

Okay,I got under there with just my tire jack(I know, ballsy),First off,I realize now that I routed the #7 wire wrong,I routed it between the head and manifold both times because I think thats where the stock one was,or i forgot and tried to route it on the outside and saw that it was hitting the exhaust manifold,and figured that couldn't be right,well after i pulled it again i had it wrapped wit headerwrap like I said,i t looked fine but I couldn;t tell if the whole wire was fine so I tried to pull it all the way through and the damn wrap had come off alittle got stuck and i probably wrecked it even more if it was burnt at all,anyway,it was cracked right by the boot,so I go back up to the autoparts store buy another wire(it was missing alot worse)put it on the outside because now i see there is a loom on the bottom to keep it away from the manifold,drive away no miss(temp did not get hot though)problem solved again but wait I drove it again later and got temp up to 210 and the miss and detonation was back I only have this slight miss when the temp is hot I checked the wire again and it was okay,as are my other wires but I cant see the ends of the ones on the pass side,i cant believe i have hd 3 problems
1.I know my opti was bad that solved my hesitation and knock problem
2.I know my #7 MSD wire was bad because it was bunt,and changing that solved my roughness and most of my miss
3.

 

MY HESITATION IS FIXED!!!!!!!!!!

Got my car back today!
ran it in 101 degree weather for 20 or so miles, did EVERYTHING I could to get it to hesitate, the car wouldn't skip a BEAT AT ALL!!!!!!


ALL that was wrong, was my Opti rotor wasn't spinning right, therefor was rubbing really weird on about 3 different spark studs(I have now clue what they are called)
and just like that, Brand new Opti ($640 later) car runs FLAWLESS!!!!!!!!!!!!!!!!!!


Also I had a exhaust leak on my passenger side, actually one of the BOLTS on my exhaust manifold was even busted!
But ya that got fixed too, overall it was a $1,100 bill at the shop, but I mean I payed them for about 5 hours of laber, adds up to almost $300 alone just for laber, then you add in the Damn $640 Opti, and thats how I fixed my problem!!!!!!!

I can't believe it's fixed it's amazing,

If anyone would like a Picture of my Bad Opti and take a look at EXACTLY what was wrong, email me at z28landon@hotmail.com
and I would be glad to send you the picture!


I REALLY!!!!! hope this helps some of you, I realize some of you have gone the "replace opti route" but maybe it's just something you can check out!

 

I don't know if I am reading it wrong, but did you pay $640 for an optispark?

 

Yes, yes I did, I didn't have time to look around on the internet. And I wasn't going to buy a re-built one for $230, from NAMPA or Autozone.
It's not just the cap part, it's the WHOLE ENTIRE thing. I got it straight from the dealer. one of my friends works there and he said that I could buy a re-built one from NAPA or Autozone, but, thats not exactly reliable........... The Plug on the Opti(not the plugs for the wires, the plug for the computer) was totally like loose and not even sitting in there right.
AND when I opened up the opti, the rotor was spinning around wrong, it was loose and like it was warped. THUS causing my car to really miss fire really bad on about 3 cylinders............Well my car is going up for sale on Monday,
I found a 1998 Z28 with only 10,000 miles on it!
kinda sucks though, I have been fighting the hesitation for over a year, and then I FINALLY get it fixed and running flawless, and then I sell it!
oh well its not like Im selling it to buy a Honda, Im selling it to get an LS1!!!

 

Anybody else have any luck with their hesiation lately?

 

New opti, cap and rotor, new water pump, new fuel filter ... also new tranny mount, cuz the other one was toast.
The tires wont even stick anymore now. Fuel filter was changed 1 week after the new opti. I still had hesitation after the new opti and water pump until the fuel filter was changed. Now it runs like a beast. Now im flying sideways down the roads of Florida. Amen! I dont know if im 100% back to normal yet though. Im gonna space my ICM a half inch and do a TB bypass and see what I can get out of that. Also re-check my wires and plugs and see whats happening there

 

ttt

 

i tried all these things too, and it ended up being a very simple fix. some resistors i had laying around, and about 10 min.

Give this a try.

 

okay,i just thought i would update everybody,and bragg alittle on how my car is running now.I checked the #7 plug wire again that i got from the autoparts store again,I guess it had come out of the bottom loom(it was a little short) and must have been up against the manifold again,but was not burnt,so I dont see why it was still missing,but the guys at MSD were cool enough to send me a new wire and since I've put it on I just have to say WOW this thing has *****!There is no miss, and the power is great enough to get the car sideways at a 1-2 powershift at 6K and i even get a nice "bark"going from 2-3.It has never flt this good, I even enjoyed the fruits of my labor and the help from this board as I ate up a new stick GT at a light(it was like he was in reverse) I had just 2 prblems then,the opti,and burnt #7 wire,thanks to everyone who helped

 

The reason these cars run good when they are cold is that:

IT IS RUNNING IN OPEN LOOP YALL!!!

The PCM doesn't listen to those O2 sensors until they warm up and the car has been running for so long. Then the PCM goes into closed loop.

Most of these problems that we are having is plug wires. If the spark doesn't get to the plug, air and fuel passes right through the engine. In the exhaust sits these wonderful O2 sensors. O2 sensors only monitor OXYGEN, not fuel. So if it senses oxygen, it tells the PCM to leave those fuel injectors open a little bit longer for some more fuel to burn up that oxygen that it is sensing, not knowing that it is unburned fuel and air in there. Rich conditions exist now, giving us poor gas mileage and running like a pig.

Spark plug wires have a bad tendency of arching under heavy loads. If you stomp the gas, that plug wires archs, and the stiuation occurs. If you're slowing down to a lower speed limit with your foot off of the gas and press down on the throttle, MISFIRE (due to dif. in load) the situation happens again.

All of this happens ONLY WHEN IT IS HOT! Closed loop. Feed back from the O2.

IF you have new wires and you're sure it it not your wires, then look to OPTI.

Hope this helps yall

D Moss




WIRES YALL, WIRES. PROB. 7 OUT OF 10 TIMES, IT IS WIRES!!!!

Congratulations on your fix droptop.

 

I came across this TSB for all our lt1's. The # is 93356D - Engine miss, hesitation, rough. Does anyone know where to find the dealer repair info for this TSB? I think this may have something to do with our problems.

 

hummmm I never heard of this TSB. sOMEONE ELSE HEARD OF THIS?