cel..P1512 VCTS

[sinuous]

Is anyone else with 01+ getting a recurring cel of P1512
vtcs solenoid valve.
(variable tumble control system)
checked and double checked vacuum hoses and plug seems fine?

Jared

[Tom @ Fast Forward]

Just to be sure, one vacuum hose from the Vacuum Distribution Block to the VTCS solenoid and another from the other side of the solenoid to the VTCS sensor. If that is correct, try swapping the hoses on the two barbs on the solenoid. That code should not occur.

[sinuous]

Tom,
I haven't swapped them yet because the way they are hooked up
matches the picture you sent me of the '05 you have.
I suppose it's worth a try. I'll let ya know.
Jared.

[elerner]

I'm throwing the same code. I had it read/reset at lunchtime. Got home, swapped out the hoses, starter her up and very quickly got another CEL. I can only assume it's the same one. (about to order a OBD reader). Hmmm, where to next with this?

[Tom @ Fast Forward]

Hmm. I have not had the code on the '05. It has been running since October.

Have any of you 01-05 guys from the first batch had that code?

[Banshee]

Nope, no codes here. I intially got a too lean code, but that's because I had the idle set too high. Since then, its been running well.

[Kyp J]

VTCS isn't on 01+, is it?

[Tom @ Fast Forward]

Yes. 99/00 had variable length runners and 01-05 have the Varible Tumble Control System. 99/00 you simply take it off and delete it. On the 01-05, you need to fake out the solenoid or get a CEL. CEL has no effect other than lighting the light but is a nuisance.

[Kyp J]

Maybe I got some initials mixed up. Isn't there something not as goofy on the 99 that VVT took the place of on the 01+?

What did the VTCS on the 01+ do in stock mode?

Anyway, I haven't gotten one of those. I won't for awhile for sure.

[Tom @ Fast Forward]

The 99-00 had a variable runner control only. The 01-05 has both a variable tumble control and VVT. The VTCS is in the intake manifold which you took off and sat aside. It is that set of butterfles right at the output of the IM as it bolts to the head. It no longer exists but the small valve that used to operate it still needs to be checked by the ECU. All you do is connect vacuum to one side of the solenoid and run a tube from the other side of the solenoid to the vacuum sensor.

I have a feeling that could be part of their problem. It see the vacuum and it never goes away. They have done too good of a job connecting the vacuum lines. Maybe a small pinhole leak in the tube near the sensor on the passenger fender would allow it to bleed off when the solenoid closes? Worth a try. The hose is cheap and the valve only turns on once in awhile at idle so the leak would never be a problem.

You can see it here http://www.fastforwardsuperchargers.com/Install/01-05-System.htm left of the VDB and the sensor over by the charcoal canister.

[Kyp J]

Maybe I was thinking "VICS". Is there something like that on older models, not on 01+?

Looking at the 3D picture, it looks like some vacuum line routing changes from the original coldside. Was there any functional changes or just for better connections due to revised placement of components?

It looks like the IAC was moved and connected differently.

Also, the "after" picture in the instructions seem to show the original prototype installation without all the improvements in vacuum lines etc.

[Tom @ Fast Forward]

VICS was the 99-00. Variable Intake Control System . Same control circuit but the butterfllies were in a different location. It shifted from long runner to short runner .

Same connections. Just moved the IAC off the supercharger. cleaned up the crowded area between the SC and fuel rail.

I am deleting the before and after pictures. too many different befores and afters out there. Each person puts their personal touch on routing and such so those two pictures are more grief than they are worth. When I finish the new manuals with all the new pertinent pictures, I think they will be pretty good. Actually, I didn't think they were all that bad before but ARB did and tye goal is to make them as happy as possible. Sent the three 3D drawings to them this morning. Manuals should go out Monday .

[99mx5]

to see the install with the new vacuum routing, check out the last two pics here http://www.fastforwardsuperchargers.com/miata-forum/1-vt53.html?postdays=0&postorder=asc&start=0

[Banshee]

Is there a reason for the rerouting? The old way works fine for me.

[99mx5]

It mainly moves the IAC from the engine to the firewall. I was shearing bolts on the IAC mounting plate. It also removes some of the redundant hoses. I also havent mounted the vacuum distribution block, so I did it all at once.

[Tom @ Fast Forward]

Mostly cosmetics and easier routing of the hoses. The function is exactly the same. A couple hoses, like the PCV valve swap connection points but the air ends up in exactly the same place.

[99mx5]

The difference for me was greater because my install was an early one when tees were used before the vacuum distribution block was introduced. I evolved my hose routing to integrate it into the OEM hardware and make it look really clean, which is why I waited until now to install the VDB.

I prefer to have a dedicated vacuum/boost line for the fuel management and have the other OEM connections at the constant vacuum port. For those who already use the VDB, the difference is small.

[elerner]

So, I installed the stock VTCS hose and vacuum actuator from the solenoid forward and confirmed that they were working in the garage. Yesterday morning on my 25 minute drive to an office that I use sometimes I didn't throw any CEL's. I left early at 1:30 and not 2 minutes in the drive I get a CEL. Checked them late last night and I had a 0106(EGR) and a 1512(VTCS). Sunday I had found that the TBA side brass fitting for the chrome pipe from the EGR plate had come loose so I tightened it up. I was hoping that was the source of my 0106 code. I may have heard some hissing from that area and I thought I might have seen some slight condensation in the EGR area. Maybe I have a slight leak. I'll have to look more closely now and may R&R the EGR and plate.

As for the VTCS, the last thing I can think of is I've replaced the 1/8" hose from the VDB to the VTCS solenoid with the original hose that ran from the Intake manifold to the VTCS solenoid. let's see what that does.

Is it possible that the VTCS and the EGR codes being thrown are affecting eachother?

[Tom @ Fast Forward]

You dont have the two hose for the throttle body and throttle body adaptor reversed, do you? It is like you are not seeing vacuum when you should be. The throttle body should have a hose to the IAC and a second hose to the drivers side of the valve cover. The TBA should have three connections. One to the IAC, one tube to the EGR and a hose to the VDB. If you think you heard hissing, maybe you have a vacuum leak somewhere? The common ground to the EGR and the VTCS is that they both expect to see a reasonable difference between atmospheric pressure and the intake manifold (TBA in our case) at idle. At idle, the TBA is at or near -18" Hg but the throttle body is at or near atmospheric pressure. If the hose were swapped, this could do it. Also, a significant leak at the TBA to VDB hose could do it.

"PCM monitors differences between intake manifold vacuum and atmospheric pressure at idle, which EGR boost sensor detects by switching EGR boost sensor solenoid. If difference is below 6.4 kPa {48.2 mmHg, 1.8 inHg} PCM determines that there is EGR boost sensor performance problem."

[elerner]

I'm connected exactly like the 3D diagram for 01-05. That diagram differs from the description you just gave. They may not make a difference but:

In the 3D, the TBA has 3 connections
1. Tube to the EGR
2. Hose to the PCV valve on the passenger side of valve cover
3 Hose to the VDB

Maybe the new hose layout in the 3D diagram has a mistake caused by moving the IAC to the firewall.

It would be nice if this was it. Hoses are easy! (sort of)

[Tom @ Fast Forward]

You are correct. I gave the old way of connecting. Both end up the same.

Hmm. That was the only common ground I could think of for the two codes. vacuum, or lack of same, at idle. DZo you have a vacuum gauge? It would be neat to tee it into the line to the VTCS and watch it. You can find the nice big 4" ones at Autozone sometimes pretty cheap (10-15$$). You even have the actuator attached so it should appear to the ECU just like original.

Maybe the problem is that it is hurricane season out east and your atmospheric pressure is so low it is just confused? Just kidding. :)

[elerner]

I'll work on getting a vacuum gauge. It'll take a couple of days.

I was also thinking that it seems weird that these codes seem to be popping at the same time. Can I have a reader hooked up to the OBD port while I'm driving the car? Anything bad about doing that? The OBDII reader is PC based and it seems to have a recording facility. I could use it not only to see if the two codes are popping at the same time, but also some investigation into Air/Fuel mix that I wonder is at the source of some of the stumbling I'm still getting. Alas...I'm getting ahead of myself. I'm going to put the new CAT in and get it dyno'd before digging into some more tuning.

Current bogey is still to get rid of these CEL's. Not losing sleep over it though.

[Tom @ Fast Forward]

I have an OBD monitor (Digimoto) and use it frequently to monitor timing and water temperature in real time. Works great. Yours should be able to do the same. It can also tell you of "pending" fault codes.

[sinuous]

Everything seems to be running good for me and I thought that the
P1512 code had went away. But......got another cel tonight.
That is the only code I'm throwing. I have not thrown the EGR (106 code)

Jared.

[elerner]

I have an OBD monitor (Digimoto) and use it frequently to monitor timing and water temperature in real time. Works great. Yours should be able to do the same. It can also tell you of "pending" fault codes.

What's a "pending" fault code? How does that work?

[99mx5]

Diagnostic Trouble Code types

There are two categories of DTC's that apply to OBDII.

Type A
1. Emissions related.
2. Requests illumination of the MIL after one failed driving cycle.
3. Stores a freeze frame DTC after one failed driving cycle.
Type B
1. Emissions related.
2. Sets a Pending Trouble Code after one failed driving cycle.
3. Clears a Pending Trouble Code after one successful driving cycle.
4. Turns on the MIL after two consecutive failed driving cycles.
5. Stores a freeze frame after two consecutive failed driving cycles.


Found that info here: http://myweb.accessus.net/~090/dtcobd2.html

[elerner]

Diagnostic Trouble Code types

There are two categories of DTC's that apply to OBDII.

Type A
1. Emissions related.
2. Requests illumination of the MIL after one failed driving cycle.
3. Stores a freeze frame DTC after one failed driving cycle.
Type B
1. Emissions related.
2. Sets a Pending Trouble Code after one failed driving cycle.
3. Clears a Pending Trouble Code after one successful driving cycle.
4. Turns on the MIL after two consecutive failed driving cycles.
5. Stores a freeze frame after two consecutive failed driving cycles.


Found that info here: http://myweb.accessus.net/~090/dtcobd2.html

I'm guessing the EGR and VTSC codes I'm getting area Type B. That's why I don't get a MIL the first time I am driving after a reset, and get the MIL very quickly the second time I start the car up. Would you agree?

[sinuous]

O.K., maybe I found something?
What is this green and black thingamabob in the vaccum line.
The hose on the bottom went to passenger side. The hose to the
right went to the original intake manifold butterfly actuator?
and the hose to the left went to the barb off the vcts solenoid that is
at a 90 degree angle. the barb that comes straight inline out of the
solenoid went to the original lower intake manifold.
I did not reuse this thingamabob. I have the hose that comes straight
inline out of the solenoid to the passenger side fender area and the
90 degree barb goes to the VDB.

[Tom @ Fast Forward]

I think that is a check valve. I left mine in. Don't know if that will have an effect or not but you might want to try it.

[ThomS]

I got the code twice now and with my altenator problems I would pick up the car or my self and throw it or me against the wall but both are to heavy. to quote someone else .
Thom

[elerner]

I've got all the stock VTCS hoses and the VTCS vacuum servo hooked up (it's easy to remove it from the stock intake manifold) and haven't thrown a VTCS CEL (a 1512) in over a week and a half. No big deal to leave it that way, though I may try to solve it again in the future.

[ThomS]

Thom

[ThomS]

Look at the check valve post here. It will solve your problem
Thom

Well I thought it solved my problem, it did not. So still confudsed here.
It lasted two days.

[Kyp J]

I just started getting the P1518 codes for the first time. Did anyone figure out what is going on with the VCTS?

I've been running without the belt so I can break in the rebuild without being tempted and don't have time to repair anything right now. After I get moved I will look at it some more. I have kind of low vacuum which I was hoping was just un seated rings and would get better with some miles. Now I'm not sure. I sprayed starting fluid all over and couldn't get any reaction, but idle has been kind of all over the place too.

Did Thom S get his codes cleared up?

[ThomS]

I just started getting the P1518 codes for the first time. Did anyone figure out what is going on with the VCTS?

I've been running without the belt so I can break in the rebuild without being tempted and don't have time to repair anything right now. After I get moved I will look at it some more. I have kind of low vacuum which I was hoping was just un seated rings and would get better with some miles. Now I'm not sure. I sprayed starting fluid all over and couldn't get any reaction, but idle has been kind of all over the place too.

Did Thom S get his codes cleared up?

NO sorry to say not yet. Still having problem. I think most of my problems are here because of the power wire to the altenator not being connected and when it touched anything metal well you know. But can I say for sure I wouldn't have any codes no. I haven't had the car running good enough long enough to find out. still not sure if ECU is ok or any other electrical wiring. I WILL ALL YOU GUYS INFORMED. Also KYP I do have one question for you, what year car do you have? Mine is 2002.
Thom

[Kyp J]

Mine is an '01.

I have been wondering if I fully tightened the alternator pivot bolt (the one that is in backwards) that provides gnd. I had the belt start squeeling but it was a new belt and probably just needed a little stretching. Too busy to get to it, plus all my tools are packed in a "POD" on the way to Texas. I'll be close to "BEGi" so I can see some other variations of boost.

I may go stare at my hoses to see if I can "Zen" the problem.

[ThomS]

Mine is an '01.

I have been wondering if I fully tightened the alternator pivot bolt (the one that is in backwards) that provides gnd. I had the belt start squeeling but it was a new belt and probably just needed a little stretching. Too busy to get to it, plus all my tools are packed in a "POD" on the way to Texas. I'll be close to "BEGi" so I can see some other variations of boost.

I may go stare at my hoses to see if I can "Zen" the problem.
Kyp
Hope your move to texas is smooth. My problem was the power wire to the altenator but yes make sure the Ground bolt is tight also.
Keep in touch. Iwas wondering if I was the 1st or only 02 with this set up
Thom

[Tom @ Fast Forward]

Thom's car runs perfect now EXCEPT one time ihe gets 1512 and the next time 1518. Evan, is yours resolved? I don't have the check valve on my 05 and don't get the codes. He has the check valve with the arrow pointed towards the fender.

Have you resolved it? It is just a nuisance and causes no problem but........

Thanks

[elerner]

I've been a lazy sh*t and still have the stock hose with the check valve and the vacuum servo in. It doesn't throw any codes that way so I've just left it. One thing though, it did throw a VTCS code about 2 weeks ago on a cold startup when the idle is low for the first 5-10 seconds. I've raised the idle (a little too high now) but it's better on a cold start.

One of these coming weekends I'll pull the stock stuff and replace with a hose and see what happens. Maybe too low an idle is throwing the code for some people on a cold start? I think a way to check would be to clear the code after the car has warmed up then stop and start the car twice and see if it throws the code.

[sinuous]

My check valve has the arrow pointing towards the solenoid AWAY from
the fender. Haven't thrown the code since ??

Jared.

[ThomS]

Took car out for test drive again today. put a few miles on it and nothing.
Under all kinds of conditions, fast , slow, lots of boost and no boost. No check valve in so far, no codes. The Supercharger has made this like a whole new car and it seems to run smoother than it ever has.
Tom you have the Idle right on .

[Tom @ Fast Forward]

That is good news. I hope you never see that CEL again.

Give it a few days of driving and you might need to adjust the idle a bit. Just remember, when you pull the IAC connector to check the idle, you will get a CEL (Bad IAC) but it is OK.

[ThomS]

That is good news. I hope you never see that CEL again.

Give it a few days of driving and you might need to adjust the idle a bit. Just remember, when you pull the IAC connector to check the idle, you will get a CEL (Bad IAC) but it is OK.

I was laughing here when I read you post. Don't worry I won't go crazy when I see the Cel. I will remember ( bad IAC ) .
:lol: :lol:
But the rest of the car is great and the FFSC has made this car run so smooth. The power is so different from stock, all I can say is WOW.

[ThomS]

After putting a few weeks of drivng on the car since I got home and now AI am getting the P1518 code am tring the the check valve gren/white to see if this makes any difference. The idle hang is not happening and the idle is perfect now at around 900 rpm with out touching the adjustm,ents so far.???? any ideas guys?The rest of the car runs great. smooth and fast.
the arrow on this check valve is toward the VTCS so I have three more options. 1. turn this valve around or 2 the other check valve or 3. turn it around, to see what happens if anything. BUt that will take three days if not more.Will keep you informed.
Thom

[ThomS]

WEll have tried all options all brought codes so I went back to no check valve and dont get the codes very often only on cold start with no warm up, just start and go. DO I have the check valve in the right hose?
The pic I am attaching shows the hose with a white line, that is the line where I put the check valve.