Hey Guys,

So I just finished a build:

a6 block
pg6 pistons
z6 head
crower stage 2 cam
crower valvetrain and cam gear
skunk2 intake mani
hondata heat shielding intake gasket
z6 tb
bisi header

I started it up the other evening, it ran just above 3000 rpms. It was a constant high idle, no surging or dropping then revving up. It just sat at 3000 rpms. I have not tuned it yet. I plugged the o2 sensor back in and had my father adjust the idle adjustments for the cable on the front of the mani over the phone, no change. I have no CEL. I will be home this weekend, and I am trying to get a good idea of a list of things to check.... This is what I have so far.

1)TB idle adjustment (though I doubt it)
2)unplug iacv and start again - what SHOULD it do if unplugged?
3)check for vacuum leaks (put soapy water in a spray bottle mist the manifold down, start the car and look for bubbles)
4)check tb gasket (I put a brand new one in but it did not meet up to the skunk2 bolt pattern on one hole)
5)check intake manifold gasket


Is this procedure a good start? I have to make the best of my time because it consists of an evening basically. I searched and this is what I got from different threads. The main difference between mine and others is that a lot of the others the OP posted about surging idles. Mine is constant just above 3000.

Anyways, I posted these pics in another thread and got very little feedback on it. We'll try again here...




The hose that is not connected was on the nipple directly under the tb opening. I removed it to pull the tb for a few minutes.


If something is not right here please let me know. I capped the tiny nipple on the back passenger side of the intake manifold, because I think it was supposed to go to purge control, which I deleted....

Thanks for your help!

Brian

 

anyone?

 

A few problems...

3.) Explain exactly how you intend to check VACUUM with soap water? Vacuum is negative pressure and if there is a leak it will just look like the bubbles are popping. You need to use something that will slow the engine down - like brake parts/carb & choke cleaner.

4.) Which hole exactly? You could have an internal vacuum leak.

I see you have a FITV (Fast Idle Thermo Valve), have you checked to see if the ceramic plug backed itself out? If it hasn't been cleaned, now would be a good time to do that. You need coolant to operate that valve correctly otherwise just delete it.

 

Well I read somewhere (I will look for the post) that you can put soapy water in a spray bottle and mist down the intake manifold and look for it that way. I also heard that I can try carb/brake cleaner and the idle should drop. I think that will be better because I can actually get under the hood and watch and listen.

I will consider this FITV delete. I live in Virginia, but it does get pretty cold here, so I am wondering if that will affect cold starts. Might as well give it a try and see what it does. I did not check the FITV of IACV that I put on it, which I should have done hindsight 20/20. They will be on my list of things to do this weekend. Thanks for the advice!

 

Deleting it wouldn't be advisable unless you tune for it. Most of the time when you delete it - it will require keeping your foot on the gas until it warms up. This isn't ideal, so I would focus on inspecting it first.

 

Look inside the opening of the TB.
Make sure the butterfly is sealing well all around.
Start the engine.
Plug the holes just inside the TB and report back if there is any change.

 

Okay. I am going to add this to my list.... Just so we're clear, the "butterfly" is the rotating disc inside the throttle body that opens and closes when you press the gas pedal, correct? I will be home Friday night, and I will try what you've said here...

Also, could I swap out the a6 fitv if I determine that the z6 fitv does not work?

 

Z6 uses a "built-in" FITV with no wires or sensors going to it.
A6 uses an external FITV with a sensor.

 

Ok, and being that it's not throwing a code, but last time the car ran on the same ecu with an a6 fitv, will the z6 fitv not communicating with the ecu affect the idle? I'm running a p28 chipped on neptune.

 

The FITV is a mechanical valve therefore it has NO electronic sensors. The IACV must be the one you are thinking of...

 

Then what does this mean? What is the sensor referred to with the a6?

 

Okay so I plugged the holes and ile went down to 2500.... What does this mean? I also tried disconnecting the IACV and the idle went down to about 2700...

 

had the same problem when i did my mpfi swap 2 years ago, i ended up making a block off plate on my FITV. worked fine but i had a number of problems trying to get it to idle down one was that the other was the top throttle body hole. there should be a rubber plug you can pry out on it somewhere that will adjust how much air goes into that top hole. i had to close mine off completely.

after all that sorting out the car finally idles between 900 and 1500 depending on air temp/ weather conditons. which i dont mind its much better than 3 grand

 

Most likely a vacuum leak somewhere. try blocking the whole tb while it is running with a piece of wood or a rubber ball and listen for the leak. if it has no leak the motor will die immediately. If it does have a leak you should find it. Did you block off both the holes or just one at a time?

 

I blocked both at the same time... I will try this block the throttle body

 

This did the trick. I blocked the tb opening with my dog's rubber ball and then heard a hissing from behind the tb. I sprayed carb cleaner and BINGO. I think it is the gasket. I have a z6 tb and the gasket is z6 but since the IM is skunk2 the bolt holes in the tb gasket did not line up with the intake manifold and throttle body right, and one of the mounting bolts went through the gasket. My buddy did not think it would hurt anything though.... I am going to get some gasket paper and try that....

 

You will find there are differences in the throttle bodies from 88-00 and between Automatic and Manual transmissions. If you search around you may be able to find a gasket that will work at your local parts store.

 

I picked up a Honda OEM d16z6 gasket this morning. It fits perfectly. I ordered the same thing from Bap geon and the packaging said d16z6.... That's what I get for going aftermarket I guess.

 

Okay so I tightened everything up on the the throttle body, new gasket, got a screw-type clamp for my brake booster line off the intake manifold, and started her up, now the motor idles around the right range but it is really really rough. I tried adjusting the ignition timing, and it idles and runs through the 1000-2500 range better right in the middle. However, the idle is VERY rough. I am trying to get a video up, but I think it may be mechanical timing. Here is the setup:

a6 block
z6 head
pg6 pistons
crower stage 2 cam
crower valvetrain
skunk2 intake
bisimoto headerdv
.060 compressed cometic headgasket

I had my p28 tuned on neptune two years ago for the pg6s and a stock z6 cam and a6 manifold. I assembled the motor with my machinist. He used the stock cam gear to make sure the timing was right, but said that it was half a tooth off because of the head/block combo. When I first did the mini-me four years ago, I moved the timing belt a tooth because when I first started it up it was really rough. This time I am afraid because of the clearances. If I move the cam a tooth in each direction, will I be okay? Or can I use the adjustable cam gear to try and adjust it? I will post the video as soon as my dad sends it to me.

 

Shouldnt you be running an adjustable cam gear for a stage 2 cam to idle correctly?.....or is that just to get the best performance out of the cam

 

I have an adjustable cam gear. The machinist used the stock cam gear to line up the motor at tdc. Using the stock cam gear, it does not line up perfectly because of the a6 block z6 head combo. So the question is should I try moving the cam a tooth or simply adjusting the cam gear? I am not experienced with adjustable cam gears, and I was going to let the tuner adjust the cam gear if necessary, but he said it needs to be "synched" but that he will adjust the gear during the tuning session as well.

 

I would just let him do it, but i would also trailer the car to him if it is too rough.

 

Well with an ls/vtec setup if you dont have an adjustable cam gear you wont have the correct timing so i would definitely try to adjust with a cam gear just nothing to aggressive like maybe 2 degrees max to see if theres a notice and always check for valve clearence but thats just me goodluck

 

^ You check for clearance but you don't know what a adjustable cam gear does?

OP - Any time you have aftermarket cams (especially in a Honda) and/or mill the block and/or head (or in this case mix an match engines) you should degree the camshafts in with adjustable cam gears. After this is done you can go through and clay the engine at different settings to determine your range of safe adjustment. Also be sure to check valve to valve clearancing as well. Regardless, if you check all that or not be sure to put it back to the settings they were at after you degreed the cams in (assuming its in the safe zone). Then if you go to dyno tune your vehicle you will have the range that you can safely adjust the cams and a "point of zero" to revert back to. Building an engine correctly takes a lot more work than slapping some stuff together and tightening some nuts/bolts.

 

Yeah I had the machine shop assemble the head for me and they walked me through the assembly of the motor since this was my first time. I do not think they degreed the cam though. I will call my machinist tomorrow and talk to him. He told me I had plenty of space when he clayed the cam, but I want to make sure before I make a move. My father sent me the video. The motor sounds like it is missing but I'm also wondering if it is just a combination of cam lope/imperfect timing in the idle. It runs a little smoother in the 1500-3000 rpms range, but I want to try to get it nailed down before the tune. The tuner said I need to ensure the timing was synched, but he would make adjustments via the cam gear on the dyno. I'm going to check my dizzy for spark at all four plugs because I just picked up the dizzy from a buddy who got it with a motor he bought. As you can see, the previous owner hacked the wire harness.... I'm also thinking I have an exhaust leak, the guy that welded my header did not check for leaks, and I have tightened everything up but still sounds like a go-kart/I'm seeing exhaust at the motor. I'm gonna have it towed up to a muffler shop this week and see if they can fix it while I am at school.

Let me know what you think though... Should I try moving the timing?

http://www.youtube.com/watch?v=Aqjrx...695&lf=mh_lolz