With 1000 miles on it, your compression numbers should be higher than that..... they are actually below spec.....

No way to adjust cam timing without pulling the cover, unfortunately. I am thinkin' it would need to be pretty far off to drop compression numbers that far.... Something strange is going on. Can you do a leakdown test?

 

Did you have the bores checked for roundness? Assuming you honed them prior to the new pistons/rings? Did you have a ridge at the top of the bore? Was that addressed? What EQ heads did you use? They had a lot of issues depending on what you got. Did they need to be machined? One of the issues with them is the rocker supports. It's possible there may be an issue with that causing a valve problem. A leak down test is in order to find where your compression is going.

 

Use sorter push rods due to the valves not closing all the way. Did you get new push rods with the cam? Did the block get decked (no)? How thick of a head gasket, stock? All the cylinders have low compression and the only mechanical piece that operates all of them is the camshaft. Are the pistons flat tops? Do they come all the way up and even with the block surface? The cam can cause vacuum problems but the 95 psi would cause it too.

 

Sadly no, I don't have a tester, or access to one. Would really rather not buy one.

 

I didn't have roundness check, but yes I did hone them, and yes I took care of the ridge at the top. It wasn't bad, but did have one.

The EQ heads I used were the the ones with preset valves, seals, etc. So not just the bare head. No they didnt need machined from what i could tell. As far as the rocker supports go, I did replace the rocker arms, and valve springs, not sure if that'd make a difference with the supports. They looked fine when I pulled em though.

But yeah, I've figured it's a valve issue, just not sure what the cause is. I'll see if I could find a leakdown tester to use.

 

I did not get new pushrods, no. And no I didn't get the block decked. The head gasket is stock thickness. The pistons are not flat top, they're dished. But yes the pistons do come all the way up to the top. I'm thinking that compression issue is the causing the vacuum issue, but I just don't know whats causing the compression issue.

Given all this, any tips? Is it the pushrods? Or are the valves the issue?

 

Also, forgot to say, I've also retimed my engine fully, and re-torqued my rocker arms down to spec.

As a general question, do you all agree it's a compression/valve related issue? Or is it something else? Could it be failed injectors? (They are ticking). There is a ticking noise from the engine that I can't figure out for the life of me, but I wanna say it's the injectors... not sure if they're bad or not though. just trying to narrow it down.

I'm still detecting spark knock with my scanner/tuner, even with timing set correctly.

Also, to note, I'm certain I have the right size pistons and rings, and I know it was honed thoroughly, so I know that isn't the issue. so IF the compression reading was accurate, itd have to be the heads or head gaskets. Just a matter of which, and the cause behind it? I'm about at my whits end with it. I don't want to take it to someone and get charged gobs just to diagnose, but I'm close to wanting to do it.

 

Ticking injectors is normal. They are just solenoids after all.

Not sure why your scanner would be showing spark knock, there is no knock sensor on second gens......

Did you have the throttle wide open when doing the compression test?

I am still thinnkin' this a valve timing issue.... or pushrods incorrect length, and holding the valves open a bit..... Can you rent a leakdown gauge from your local parts store??

 

Yeah I'm not sure why it's showing spark knock, it's weird. And no, I didn't have the throttle wide open. It varied, I let it idle, revved it, held it at about 3k rpms, etc. Got a full graph of info on it.

And alright, I'm hoping it's something like that, not too hard to fix at least, just hard to diagnose.

I'll see if I can rent a leakdown gauge, not sure if I can or not.

 

The engine shouldn't be running for a compression test.... and the throttle should be wide open, else you get inaccurate readings... (low)