Vacuum

[Hogg]

Hey Team,

I am having some cracked and leaky vacuum lines underneath the plenum and around the engine - my first idea was in some cases to cut them down and plug them, or in the case of some on the valve covers and ontop of the plenum - get tiny cone filters and clean up the engine bay a bit.

Im lead to believe that cracked hoses and vacuum leaks are the reason behind me Engine light being on.

Any opinions?

Thanks,Spence

[Q45tech]

The MAF/ecu software is designed for a CLOSED SYSTEM. Creating a after MAF air leak will cause problems!Venting crankcase/via valve cover vents gases to air is very illegal and will surely make matters worse.

Why not maintain system as designed so that you can achieve the as designed performance?

Just someone thinking this might work is scarey from a technical point of view shows lack of understanding about how modern engines function.

Modern being a 20 year old design! That is still copied today [2008] by most manufactuers.

[Hogg]

The cluster of Solenoid vacuum hoses, and the ones going into the plenum as well as some underneath it etc. Can those be cut and plugged? Im wondering how all these guys with custom intake manifolds and performance setups can have their motors run let alone smoothly without those doodads?

-Spence

[tmorgan4]

Yep, there are quite a few of "us" that have taken out all of the EGR plumbing and the engine runs fine. The only symptom I have left over is the EGR Temp Sensor code. To get rid of the EGR you're going to have to do the following:

Remove all EGR plumbing, valves, and solenoid. You'll be left with a big hole in the driver's side exhaust manifold which can either be welded shut or can be plugged with a bolt or setscrew. The small EGR line connections on the intake tube will need to be plugged. Where the EGR valve connected to the intake plenum will need to be plugged as well, and any 300zx EGR delete kit includes the necessary plate. Can't remember what else you'll have to remove.

I ended up removing basically the entire PCV system as well and have my valve covers venting to the atmosphere. All the breather filters I found didn't fit the valve covers so I ran hoses from the block fitting, and each valve cover to the drivers side of my engine bay. Eventually I'll hook them up to the catch can I've got.

[Hogg]

That sounds wicked, but yeah even the Charcoal Cannister stuff I dont know if I should touch that either... Clean engines are great - it just seems the VH45DE is basically wrapped in **** inside the Q45. Much of which is probably overkill? I know someone will say Im wrong, but I dont need to pass emissions or anything I basically just want to keep it simple and as little restrictions or metering as possible.

[tmorgan4]

If you do away with all of the EGR and emissions crap then there's no reason to keep the charcoal canister. Just one more thing to free up some space in the engine bay.

[Hogg]

Cool cool, I just heard it would run like garbage without it. Hope not - but thanks a lot for the info!

[tmorgan4]

I guess I'll be a little more confident in saying that it doesn't run like crap as soon as MINE doesn't run like crap. Although it's because of a vacuum leak between a lower runner and plenum. I'll have mine running well someday, and then I can give real advice.

[Q45tech]

Some people care about perfect idle smoothness and superior highway MPG, some are oblivous or have different priorities.

Removing egr will definitely decrease highway MPG and wasting the gasoline fumes by not burning them thru evap system just causes atmospheric problems.

None of these things are germain to acceleration performance since they are already shut off during acceleration to not create any impact.

[Hogg]

I dont care so much about gas mileage as Ill be building up the motor as soon as I work out its bugs, but I want uber smoothness and perfect running before I do any modification - Trying to achieve that would most likely be assisted by removing the leaking and cracked emissions hosing and failing vacuum lines throughout my motor.

[Hogg]

Im thinking it'd be great to have a whole list of deletables throughout the Q45 and the VH45DE, it seems race builds and swaps are growing in popularity and I dont think I will be the only person asking these kinds of questions.

-Spence

[SuperHatch]

Im thinking it'd be great to have a whole list of deletables throughout the Q45 and the VH45DE, it seems race builds and swaps are growing in popularity and I dont think I will be the only person asking these kinds of questions.

-Spence

I'll make a list for you with pictures this weekend. I have deleted the EGR, PCV, and a number of other "extras" since my car will not re registered for street use. As Q45tech said, none of the things I've doen will effect WOT performance, just economy and emissions.

[Hogg]

Wow that would be cool, I just had my car in my shop at Toyota and the head technician said Im definitely missing and running very rich which is causing it to run really rough. He also said somewhere unmetered air is entering the engine and making it run like crap.

-Spence

[SuperHatch]

Wow that would be cool, I just had my car in my shop at Toyota and the head technician said Im definitely missing and running very rich which is causing it to run really rough. He also said somewhere unmetered air is entering the engine and making it run like crap.

-Spence

Just as an FYI. Unmetered air entering the engine will cause it to run lean, not rich.

[Hogg]

I think its a mix right now, flooding injectors cause it to burn tons of gas and smell like fuel out the exhaust, and miss like crazy when the engine is revved up.

The unmetered air entering it either by the broken plenum bolts and f*d vacuums.

Im thinking its just really messed, when it starts getting warmer if it doesnt sell then Ill start rebuilding it and get it back to health, then start modifying it I hope.

-Spence

[T45]

I would just stop everything and pull the plenum off, replace all rubber, new plugs and ohm all coils and injectors, pulse the injectors to make sure they are not stuck and if money allowed send them to get them cleaned at deatchworks. After that I would re-assemble, making sure the intake is clean and all passages unblocked and also check all your voltages on the tps and readings on maf and your other sensors. Shouldn't cost more than 500 if you do it on the cheap and will run like a top when you're done.

[Hogg]

Yeah Im thinking of just getting a set of 8 reman'd injectors from Deatchwerks, itd be money well spent I think. And then yeah pull the plenum and slowly rebuild it, put the new sparkplugs in and then check my coilpacks as well to make sure everythings running top!

Just waiting for the weather to get warmer so I can work on it and not freeze and be all pissed off.

[Steve Lloyd]

I'll make a list for you with pictures this weekend. I have deleted the EGR, PCV, and a number of other "extras" since my car will not re registered for street use. As Q45tech said, none of the things I've doen will effect WOT performance, just economy and emissions.

Did you ever get this list with pictures done?? I'm starting to strip down my engine and want to remove as much garbage as possible. It's a track only car, so I'm not worried about gas mileage, I just want to remove as much unneeded things as possible.

Thanks...........

Steve

[scir16v]

I'll make a list for you with pictures this weekend. I have deleted the EGR, PCV, and a number of other "extras" since my car will not re registered for street use. As Q45tech said, none of the things I've doen will effect WOT performance, just economy and emissions.

I'd like to know this as well. I have it on the stand right now, but I'm going to be cleaning the timing chain covers, valve covers, and intake manifolds real soon. After that, I'm going to assemble and get hoses that are needed. I'd rather not spend unneccesary monies.

[SuperHatch]

I'd like to know this as well. I have it on the stand right now, but I'm going to be cleaning the timing chain covers, valve covers, and intake manifolds real soon. After that, I'm going to assemble and get hoses that are needed. I'd rather not spend unneccesary monies.

Honestly, I completely forgot about this thread. My apologies...

I don't have pictures, but I can tell you what I did.

- Rear ports on valve covers connected to crankcase vent in rear of valley.- Middle ports on valve covers connected to each other, nothing else.- Front ports of valve covers vented to atmosphere with filters.- PCV valve port on manifold capped.- IACV removed from rear of plenum.- IACV port below throttle body capped.- Fuel Damper port vented to atmosphere.- FPR port connected directly to plenum.- EGR Valve removed and blockoff plate installed.- All ports on throttle body capped.- Coolant lines on throttle body and ERG bypassed.- Idle set with throttle body stop screw at 800 RPM.

There may be other things, but this is the gist of it... car runs fine, much better than other vehicles with this amount of bypassing done. Once at operating temp everything runs perfect, only at cold idle are there any slight misses or hesitations.

Hope this helps!!

[Infinitiguy19]

Do you have any dyno or 1/4 mile times with this setup?