FASTFATBOY

Opti harness and or the engine ground from the left front frame rail to the engine being off will also do it.

Put washers behind the coil to space it away from the head.



David

WestCoast96Z28

My advice..forget about the past and move forward with your LSx engine. I know you're pain, but fortunately (cross my fingers) I haven't had to throw that many parts at it. I've had some bad months I call my "random low RPM miss" days.

But I understand the frustration...many many times, I've thought about selling my 96 LT1, but when I finally get it running again, I want to keep it. Then something goes wrong (latest was tranny), and then I say I'll fix it and then plan to sell it, but after fixing it, I want to keep the car. I've thought about just buying a fast car that I don't have to mod...something like a Vette or Cobra (yeah, I said FORD). I figure it's comes stock with power from the factory, hopefully more reliable. Then I drive around and see how many "stock" Vettes, Chargers, and Cobras there are out there and I think..."what's the point of just staying stock...anyone can do that".

So back to my LT1, which I finally tightened a loose header bolt...damn SLP...NO clearance for the wrench on the 2nd bolt for cylinder #1. Those with SLPs know what I mean.

That's the fun of modding...it would be hard to fine 2 cars with the EXACT same mods on this message board. Our cars are about unique as each of us are.

Good luck with your rebuild!!

95z28 -quicksilver

Thanks for the understanding... Yeah 2 and a half years of diagnosing and still nothin'.... I need some reliability in my life. Time to cut my losses like a shoulda done a long time ago. With any luck I will be done with the swap by the beginning of summer. Can't wait

SS RRR

Sooooo was the ignition put on an oscilloscope or not?

seawolf06

Sorry to hear about this bro. I would like to see what it takes to put that LS1 into your car, though. I really wish I could have those heads, too!!

95 Civic

ive had a couple of LT1's and I loved em', but they act like they dont love us...lol... does it feel like your actually losing power or hear like its missing...
when my first lt1's tranny was going out, it made alot of popping and "missing" noise.... Just a shot in the dark.... I did alot of chasing that time and then my tranny took a sh** on me. That was with help of a guy thats owned 11 lt1 cars and 5 ls1 cars... I thought he knew something too... lol...

Pyrodawg

whatre u looking to get for the heads?

Stroked&Poked

I don't know everything you checked,i started to read the post but decided to just put in my two cents. I have a 94 corvette, 6 spd with 43,000 miles on it. It went from running fine to having a miss over night. I checked everything i could until i decided to do the opti. I pulled everything apart and took the cap off of the opti and the contacts were shot. When i saw that i just knew that was the problem so i put a new cap and rotor on it and also put in a new set of NGK plugs. I got her all back together, fired her up and everything seemed okay. I only drove it for about two miles ( it was late at night ). The next day i went out and it was running fine then it progressively got worse. I wasn't a happy camper. I was totally lost. I started checking everything all over again then for the hell of it i decided to put in another set of spark plugs. And that fixed the problem. What i'm getting at is that i'm guesing that the little miss i had was probably the cap being so bad and then believe it or not i got a bad spark plug. I looked at them through a lighted magnifying glass and they all looked fine. One of them was obviously broken inside somewhere.

This is just a thought. I hope you have luck figuring it out or with yur new motor.

slowride94z

I also had A bad plug the engine missed at about 5000 but would rev on up.

David94TA

http://www.ls1tech.com/forums/showthread.php?t=796022



When my LT1 gives up, I'll be making the switch.

KyleBlue85Iroc-Z

so what are the possibilities of this being a short block problem? if they're slim, I might be interested in that 355 short block. My Z just blew a head gasket or even more and i'm done with the stock block for good! I'm in DFW, so not very far away!

How much would you want for it?

Kyle

95z28 -quicksilver

As for the diagnosing... I have put 2 opti's on it to try to fix it. One stocker and then an MSD. No change. Also the spark plugs were changed out too along with the plug wires.

As for this problem being with the shortblock, i seriously doubt it. Its oil pressure is great, no pinging, no knocking. I also had a compression test done to make sure the piston rings sealed correctly and it was good. Leakdown test also showed up good. I am looking to sell the shortblock for around 2500, and the heads for 1,000. Or both of them together for 3K. The heads flow pretty well

Intake:
.100-------61.9
.200-------89.1
.300-------173.8
.400-------220
.500-------253.6
.550-------264.3
.600-------273.9

Exhaust:
.100-------58.3
.200-------115.3
.300-------147.1
.400-------174.00
.500-------181.8
.550-------185.5
.600-------185.9

2.02 intake valves, 1.55 exhaust valves, stage 2 port, 5 angle valve job

and have brand new beehive 918 springs on them that have maybe 50 miles on them. heads themselves only have 1500 miles on them. I have the flow sheets and dyno numbers that my car put down with these heads are in my sig.

KyleBlue85Iroc-Z

we might talk soon. could possibly be interested in block and/or heads.

95z28 -quicksilver

Just let me know, as soon as somebody gives me the thumbs up on a definite sale then i can have the engine taken out within a couple of days.

jbird

My car had a miss like that for almost two years. Every time I put a on a new opti the miss would disappear. I went through 3 icm's, 7 coils, a pcm, 4 sets of plugs, 3 sets of wires, more optis than I can remember (over 10) two or three fuel filters, a new fuel pump, cleaned every ground on the car, etc. One day on a whim I bought a new opti harness. The old one ohmed out just fine, but I thought, what the heck, it isn't going to hurt anything. That was almost a year ago and the car has ran great since. It was at four different shops trying to figure it out. Fifty bucks for a few pieces of wire and it was cured. Good luck with the LS1.