Intermittent Lift Issues

Posted by: @marsrock7

Well it runs and I didn't screw up the timing. Performed flawlessly for about 20 minutes then when I punched it out of a cloverleaf turn getting back on the highway it faceplanted again. Drove for about an hour last night and the bark with no bite lift appears to be nonexistent. It either works right or faceplants. Got the faceplant a second time when I tried the 6th>3rd shift at 65mph in a straight line. I'm trying not to feel too disappointed because the car does feel better as a whole and now I'm not worried about the cam gear exploding. Lift works way more often than not. Startup rattle is gone as well.

I think I solved half of a two part problem. Now I suspect the spun metal cat installed a foot downstream of the header has bit the dust already. There is a very subtle rattle sound in the exhaust I don't remember hearing before. Maybe lateral forces and/or sudden pressure changes in the exhaust are bouncing loose substrate around and causing an intermittent exhaust restriction. Might be time to head out to the country, drop the exhaust and put in my earplugs for some testing. 

Only other thing I can think of is an oil pressure issue which I certainly hope it isn't. Not sure how I would track down an intermittent oil pressure loss. I also feel like I'd see more evidence of low pressure in the head if that were the case. 

 What I would do is find out if lift is being triggered.  If you can rig up an induction sensor on the lift solenoid wire or run the wires back to where you can connect it to a multimeter you can have someone confirm that the switch is being activated when you hit 6k.  If and when it fails and the lift solenoid is not activated then you know the problem is electrical. If it works then the problem is mechanical.  

@dev lift is being triggered. The changeover is audible and the facepant happens at changeover. Either I get the boost in power or I get a sensation similar to running out of slack on an anchor line. Doesn't sound or feel anything like going over 6k when engine is still cold.

Before the most recent work sometimes the laggy feeling could be felt before hitting lift but the changeover still caused a hard jolting slowdown. Didn't run into that last night but maybe with this work done I can narrow down what triggers the remaining issue. I just went out and smacked the cat on my exhaust and I think the substrate has come loose and is just bouncing around in there. Probably wont be able to mess with it till next week thou.

Posted by: @marsrock7

@dev lift is being triggered. The changeover is audible and the facepant happens at changeover. Either I get the boost in power or I get a sensation similar to running out of slack on an anchor line. Doesn't sound or feel anything like going over 6k when engine is still cold.

Before the most recent work sometimes the laggy feeling could be felt before hitting lift but the changeover still caused a hard jolting slowdown. Didn't run into that last night but maybe with this work done I can narrow down what triggers the remaining issue. I just went out and smacked the cat on my exhaust and I think the substrate has come loose and is just bouncing around in there. Probably wont be able to mess with it till next week thou.

Maybe it is your clogged cat. It’s probable that if the material is shifting around it could partially clogging. 

Don't know much about catalytic converters, but pretty sure they aren't supposed to look like this...

Cat is 4" wide and cat matrix is now under 3" wide. The divots in the side of the matrix are from where it was hitting the post cat O2 sensor. 

Now to find someone to weld this empty carcass back together....

Oh_my 🤨 😮 😲 😳 

Uh, is that a PPE cat? I have been using a great local welding shop for my exhaust welding, and they make great welds. I'm in Indy. If you'd like pics, get me your cell.

Some of the aftermarket cats use spun metal housings where the metal is fabricated around the cat material so it doesnt come loose. It is necked on both sides also. 

It would be interesting to see if it solves the lift issue. 

It is not a PPE cat, but a cheap spun metal piece. The only reason I went with it was due to the spacial confines I had to get a cat on this system at all, at a reasonable price. Given the outcome, I'm glad I didn't spend real money on a real cat. The melting could've been due to my tinkering with the fueling, timing, etc via the EMU (I didn't do anything drastic, and back to stock maps for now), or maybe due to the VVT gear not functioning properly, or a combination of all the above. 

Nonetheless, this C section is complete and the patient is buttoned up. Problem solved. It would appear the losses have been gradual and I didn't notice how much power I was missing across the board. With the piping clear and new VVT components, I feel like the car just lost a couple hundred pounds. The permagrin is definitely back!

It was a cheap Flowmaster cat.

Flows better now for sure...