Just got a brand spankin new opti under warranty, wasn't the issue. Brand new plugs, brand new wires. Opened the throttle body idle screw to keep the butterflies open a little more. I have a ticking noise somewhere.

It will behave normally when its cold (still ticks) but it idles fine but the car shakes pretty badly (warm and cold) and when its warmed up, the car will start jerking around and will eventually kill itself. I can't figure this crap out. I took a mechanics scethoscope and couldn't find where the ticking is. Its not an exhaust leak and im not sure if its the rockers. I can't even tell which side its coming from because the exhaust is so loud.

Could this be the sign of the valves being too tight? I haven't pulled the passenger side valve covers yet because I had to head back to work, the drivers sides are okay.

Also, the coolant line that comes off the back of the heads, which line on the throttle body does it go into? The middle line or the bottom line? I got mine currently inside the bottom and the middle capped off. Thanks.

 

Forgot to mention, every cylinder is getting spark and fuel. I took the scethoscope to the injectors and can hear them clicking.

Someone give me a hand im getting tired of this guesswork .

 

Wow.

Shakes itself? Has it done this since you got the motor back or just recently?

 

I just got it running. Yes, shakes, I had this happen once before when I had 3 cylinders not firing on the old 350. Car feels like a vibrator. So Im guess valves too tight?

 

Okay, something real screwy going on here.

1st) I checked the drivers side rockers, their fine.

2nd) I found the ticking noise I believe, it was the belt tensioner, seems I installed the washer backwards.

3rd) I have a slight miss that comes off and on for some reason and the opti is 100% brand since 2 days ago.

4th) As soon as the car warms up (about 20 minutes or so) the tach goes wacky and the car tries to stay alive, the tach will jump to 3500 rpm and the car wont be at 3500 rpm and it jumps back to 1200, and to 2000 and the car is actually at 800-500 rpm trying to stay alive. What is causing the false rpm reading? Its not my dash wiring or my tachometer (aftermarket). I have a feeling its a ignition sensor. Doesn't happen when it goes to closed loop, more like when the engine is heat soaked (engine bay gets pretty damn hot, temp always stays at 210*) Perhaps the ICM?

5th) My vibration. I noticed my balancer has the middle rubber piece some what coming out of one side, not a lot but a little, could this be the problem?

Please help, thanks.

 

Tach jumping like that is usually a bad ground.

 

Ground points are all good, thought of that myself, I got six on the chassis and all grounds on the drivers side head on the coil are great, I even soldered the wire to the O connectors. Its definatley a electronic sensor getting heat soaked. The opti is brand new, only thing I can think of is the ICM near the drivers side head getting heat soaked.

 

Is it possible for the ICM to be heat soaked and is this a common issue? Im running out of ideas here guys =/.

 

Why don't you use something like a timing light to see if there are any plugs not firing consistanly? If either the coil or the ICM is breaking down, you should see the effect on different plugs.

Also, you can see if a device is breaking down from the heat by heating it up with a blow dryer. If it's ok when it's cold but heating up makes it crap out, you found it. The trick is to heat only one device at a time. You also don't want to heat anything up each time you test the engine to see if you found the part that when heated is causing the problem.

One other thing. Have you checked to see if you have a dead cylinder? Since you mentioned that it runs rough all the time, chances are good you got one. Pull the plug and inspect it if you find one. Swap the plug and wire from another cylinder too.

 

It really really sounds like a bad ground, did you scrape the paint off of the block wherer the grounds go, have you checked them with the engine shaking with an ohm meter? Usually when the ign module goes bad it goes bad wham, no run. I would check the grounds and inspect the wiring. Are you absolutely positive you have all the wires to the opti in the right order (sparkplug wires)

 

Sigh....its not a ground, i've already explored that possibility. I have 6 chassis grounds, all grounds on the actual harness were made with 14 gauge and thicker wire, they were also soldered onto the connector that hugs the bolt + crimped. Most of my I know its not a ground because my electric waterpump is still running when the car dies as long as the key is on, its on the same ground as everything else.

Im for sure its a heat soaked sensor because after it dies from being too warm it will not start (no spark) until I let it cool off for 10 minutes.

So once again....I ask.....is this the sign of a ICM issue?

I don't wanna throw down $68.88 for a new ICM if there is another sensor that could cause this.

 

Is the ticking still going on? could it be setting off the knock sensor? It seems a far stretch but I've seen it before.

 

Knock count isn't rising beyond normal. That also wouldn't explain why it wont fire up after its heat soaked =/.

 

In regards to your question regarding the coolant line.

The coolant line from the back of the heads does not go into the throttle body, it should go directly into the radiator. I believe it goes on the 2nd nipple down on the radiator filler neck.

The middle line on the throttle body is suppose to be PCV, and I believe the nipple below is for coolant passage (heats up the throttle body).

That could explain why engine is running hot.

 

Its always been hooked up there... Just didnt remember if it was the middle or bottom. There are 3 holes, middle is plugged, top is PCV and bottom had the coolant