Thread: Heavy Isolated Misfire Under Load

My 97 gtp is having heavy misfires on Cylinder #1 when accelerating any harder than grandma mode. The problem began after my 1.9 Rocker Install.


I re-inspected under the valve cover. I ruled out the spark plug, the wire, the coil pack and the ICM. I have no codes besides the misfire.

Any Ideas or suggestions will be greatly appreciated.

Time to look at your fueling situation. Swap injectors...see if the issue follows.

I found the problem. One of the pedestal spacers is missing. Which is odd because I remember taking the last one out of the packing.

Anyway the box that had the packaging is at the dump now if it was in there.

Where can I buy them?

might need to contact harland sharp.. Or maybe you could bring a normal spacer to a machine shop with a rocker spacer to have them machine in the curve?

A normal spacer? Where would I get this normal spacer?

Contact harland sharp, and I wouldn't drive the car until it is fixed.

Originally Posted by Drunkie

Contact harland sharp, and I wouldn't drive the car until it is fixed.

I already contacted them.

I dont really have a choice, I have class and work and this is the only car I have available to me atm. I made my own spacer in the mean time and I disconnected the boost bypass solenoid.

Originally Posted by HighOctaneRacing

At least you found the issue

Tell me about it. I'm so relieved. Since friday every ounce of free time I've had has been put into that car. Im drained.

see what happens when you work in the dark???

good find tho.

Originally Posted by Scottydoggs

see what happens when you work in the dark???

good find tho.

Thats what I've been telling myself all day.

"Thats what I get for working in the dark"


Hopefully I didn't bend the valve or damage a piston. That random noise I heard was knock due to the built up pressure not being exhausted quickly enough.

I've seen two come up missing and I know they were installed.

Hmmmm now who the hell did I give that bag of spare spacers to? Right..I'm the guy that had spares, and gave the bag to someone.......

I hope its not in the engine somewhere.

Harland sharp got back to me they're sending me one for the price of shipping.

Originally Posted by Jomamma

A normal spacer? Where would I get this normal spacer?

Like a bolt spacer from ACE or similar lol. like what we put in the accumulator for shift kit, and just have the curve machined into it. But since you already have one coming from HS you'll be good to go.

It's also not a straight spacer.. there's an angle. Which led to the great rocker issue of a few years ago.

So what's this issue and how can I prevent it ?

Dude.. IDK.. it never happened to me directly. I was just the guy handing out pedestals. Had a gallon bag of them.

If yours is a newer set you have nothing to worry about. it was the original ones that first came out from HS that had an issue. Mine are great!

Its all good . One will be here by Friday. Those guys over at Harland sharp are great.

Put the new spacer in.

Car still misses under throttle.


Now I can see what everyone was talking about. The spacer I got had a little dot on one side. I guess I didn't have the revised set.