Maybe somebody can help me with a problem that my 94 LT1 Z28 decided to have...

After I got back from I parked my car on the street cause I was going somewhere else later on....

Well I jump in my car and started her up and it had this weird vibration that rattled my interior while the engine was running, I go to turn on the heat and everything in my car is vibrating worse and the it sounded like it was going to quit.....
The exhaust sound changed from sound like a stock V8 to a cammed V8, so I turned the heat off but I still got a vibration like the first time... The idle hovers at 500- 650rpms but mainly at 500 in gear and park, I know its supposed to be around 700 or so, so I gradualy reved the rpms up and the vibrations was still there

Well I put my car into gear and the vibration has gotten worse and then turned on the heat and everything was rattling more worse than before...

So I listened to my exhaust and it sounded like I was running on 7 cylinders but when I drove it I still had the power of all 8 cylinders and no vibrations.... There are no vaccum leaks what so ever....What gives???

I have come down with some thoughts in what might be wrong...
1. Ignition Coil
2. Ignition Module
3. Plug wires
4. Opti
5. o2 Sensors

Can anybody help me???

Thanks

 

#1 check your wires to make sure none are fried.
#2 opti...

sounds a lot like a bad opti to me. how many miles are on yours? could also be a bad O2...

don't worry, it's not that big of a problem.

 

i know this probably isnt it.... but ive heard that a descreened maf will sometimes cause this if the engine doesnt adapt correctly to it..??? i have no idea but ive wondered if this was true.

 

Sounds like you have a dead hole. Like enisguy said, check to see if you are getting spark to each cylinder. Are you throwing any codes. I had a similiar problem when I descreened my MAF. Something must have got in my air intake and damaged one of my resistors in the MAF. It threw a code for this and ran like crap. It is really easy to test the MAF with a voltmeter is this is the case.

 

Could be a number of things, I'd definitely do what they stated above first, check all your wires are good, not burnt, plugged in, etc. Then plugs, coil & 02 sensors. Autozone will scan it for free and I'm sure you have an SES light, probably blinking (multi-eng-misfire). Optis are evil sure but a lot of times it's something else. I just went through 2 weeks of diagnosing mine running crappy and turns out it was my drivers side (3-week old) 02 sensors...they don't like race-gas...well lesson learned I really just didn't know any better, but it's runs like a champ again, all it was. Codes were P1133 & PO132 I think for Bank1 Sensor 1 (drivers side 02) faulty. Good luck, let us know what you find, helps us all diagnose.

 

Well my # 8 wire was ripped before (the car still ran normal) so I taped it with electrical tape and it still ran fine... but ill check to see if the wires are fireing... Ill let ya know what i find more

 

Sounds like it's time to get a new set of wires.

 

Lol I agree... they aren't that expensive. Like 50 bucks. I'd say 90% it's that wire you taped that isn't getting spark to a cylinder...

 

Well i tested all the wires and Im getting spark.. Even the one thats taped is getting spark.... With my check ill go throw some good ones on..