LSX454 swapped 95 BASS burb.

[shady]

So I found a new issue I have to address.

I put that wilwood adjustable prop valve in, in place of the ABS unit.

When I bled the brakes I had pressure coming from all 4 bleeders when the pedal was pushed.

But no matter where I set the knob I seem to have no rear brakes.

I'm going to have to pull it apart and see if the shoes are shot or something.
I noticed that when I was backing out of the shop drive, down hill on gravel, the front tires would slide. I adjusted it from one extreme to the other and did some rolling forward on gravel hard stops.
Fronts just slide, seems like nothing at the rear either way.
Burning the crap out of my new front pads.

 

[folkenheath]

I think that prop valve is directional? Double check that. I put mine in like 20 years ago so I don't remember.

 

[shady]

Hard to mess this one up lol.
I probably should get in there and check the rears anyway. Beings it has 409,000 miles on it, and I have no idea when they were last done.

 

[shady]

Been getting used to the driving. And think maybe most of my problem is the fact that I've been DDing big blocks for almost 4 years
So I'm not worried about that.

But what's annoying me more than anything is the ramp up after starting.

Even when hot, this will start up, ramp to 1800 or so and hang there for a while. Then slowly ramp down.
It's annoying as hell when in drive throughs, at home trying not to wake everyone up, at the shop moving things around, etc.
Because I have to wait for it to do it's thing and get down to idle, before I can put it in gear and go. And It's not exactly quiet.

 

[shady]

I got into the idle stuff, and found a ramp setting that I thought was right, and adjusted it. But it seemed to make no change in anything,,,, at all really.
I'll look up the exact setting I changed next time I get my laptop out.

I'm actually not sure that my last round of tune changing that I mentioned here took.
Because I put the TC lockup settings back to what I thought were original and it's still locking up around 42 where I had it set before.

 

[folkenheath]

Did you look at your idle speed chart? It has different idle speed targets based on coolant temperature.

Also, make sure you adjust the butterflies for an IAC open about 5 - 15% at idle when fully warmed up. Then recalibrate your TPS in the software.

Are you sure you don't have a vacuum leak? 1800 RPM sounds very high, like something is way off.

 

[shady]

It starts, ramps up to 1800 within a second or 2, then hangs there a second, and starts falling back to normal idle over the course of about 2-3 seconds. Does it every single time it's started no matter the temp.

I'll check that iac and see what mines at.

 

[folkenheath]

It starts, ramps up to 1800 within a second or 2, then hangs there a second, and starts falling back to normal idle over the course of about 2-3 seconds. Does it every single time it's started no matter the temp.

I'll check that iac and see what mines at.

If it's only seconds, for that you want to look at the IAC Parked position. Its what the IAC valve is open too while you are cranking, sounds like you need to lower it some, its also based on coolant temperature.

 

[shady]

The vid a few posts up is what it's doing. I figured when it's warm it'd just start and idle.
Should in my opinion anyway lol.

 

[folkenheath]

That vid doesn't show the IAC position, you need to lower the "IAC parked" position.

 

[shady]

Did you look at your idle speed chart? It has different idle speed targets based on coolant temperature.

Also, make sure you adjust the butterflies for an IAC open about 5 - 15% at idle when fully warmed up. Then recalibrate your TPS in the software.

Are you sure you don't have a vacuum leak? 1800 RPM sounds very high, like something is way off.

So do I open or close the butterflies for that.
Maybe it has a vac leak because my butterfly is as closed as it gets and my iac is 0%. Opening them does nothing to the iac position.
Curiously opening the throttle with my pedal does make it go up. So I'm confused

 

[shady]

Only way I can think of it'd have a vac leak is a cracked intake. Which is new...?

 

[folkenheath]

Is it a stock throttle body and seal? I've seen throttle bodies that are hollow in the back that have gaps and need a plate to seal correctly to the intake.

There also could be a vacuum port not plugged somewhere?

BTW, that is the better proportioning valve. The one I have is less expensive one that only hooks inline to the back brake to reduce pressure of the back only, I believe that one is directional.

Did you try changing the IAC parked position in the software?

 

[shady]

I don't mess with the parked position yet.

All of the open ports were plugged/capped.
The throttle body is aftermarket, but the back was smooth .
I AM running a catch can off the intake with a pcv valve from a BBC in the line right after the valve cover.
This engine did not have a pcv valve stock. Never seen that before .
It had a nipple on the valve cover, and a nipple on the stock intake. Just a plastic tube between them.
I used the TBSS intake, and the nipple molded in the top of it from the catch can. Then came off the nipple on the valve cover with a flared piece of hose that fits the pcv valve snug. And came off of that to the catch can.

The more I think of it the more it seems like there's a leak though.
Only vacuum line I'm running is to the terminator x ecu.
I did get a new map sensor, and it's installed. But I have the terminator set to use the one in the ecu since they recommended that with a non boosted application.

 

[folkenheath]

Did you use a pcv valve in series with the catch can? Or is it just wide open to the catch can and then atmosphere?

One test would be just unplug that port at the intake side while idling and see if it changes much, if it doesn't, then its a vacuum leak that's still a vacuum leak.

If you have a new MAP sensor I would plug it in and use it, it should be faster response time than the hose to the ECU. They can both work satisfactory, just the MAP sensor on the intake has a slight edge, if it's free, use it.

 

[shady]

Couple pics I took of the computer while I was playing with it.

 

[shady]

Pcv valve is immediately off the valve cover, hose goes down to the input of catch can, output of catch can goes up to barb on top of intake.
Brand new 3/8" valve on the bottom of the catch can for draining.

Only reason I used the map in the ecu is the directions said go ahead lol.
All I should have to do to use the one in the intake is switch it in the program I believe. It was 100* out and I was sitting in it with no air trying to iron the idle out. I got frustrated quick and said fug it and went home lol.

It idles and runs fine.
It's just that high idle hold every time I start it, and I have noticed every now and then when I'm cruising through town, and I let off it seems to stay at 1200 or so and I cruise like 30 without having to touch it. But when I brake to a stop it idles normally again.
That's why I never really worried about it.
Something is definitely not right though.

 

[folkenheath]

Well that data shows there is air somewhere else, the target idle speed is 700, it's idling at 942, and the IAC and throttle are both at 0%. (Assuming the IAC is working correctly, which is something to check).

So if you can't close the butterflies more at idle with the idle screw, then air has to be getting in somewhere else. This may also affect your performance at lower engine RPMs if you have a vacuum leak, which is what you were concerned about.

 

[shady]

Yeah I never thought about a leak until I started seeing the same stuff yesterday.

I've always thought it was odd that it wouldn't idle down to my set point, which started at 780.

The set screw for the butterfly has been all the way out since day one. I figured I'd adjust it as needed when I got it running and just never needed to.

 

[shady]

I'll unhook the pcv system first and go from there eliminating possibilities.