Got my built 7m running last night!! couple questions. Vid. on post 66

[92nsx]

IC piping is as follows for now. Yes CT-26 for now, just for start up/brake in and to ensure the engine was built "right".
Hot side is: 2" piping, next a 2 to 2 1/2" coupler to IC. IC has 2 1/2" in/out. Cold side is: 2 1/2" to 3" coupler. 3" piping then a 3" to 4" 90 degree coupler to TB.
I Built it for a larger turbo but wanted to make sure this 7m I had build was done right. See build thread. The only thing I planned on changing when I install the turbo (what ever I make my mind up on) is the hot side to 2 1/2" piping.

Is this also adding to my Idle problem?
Isn't a closed system a "closed system" and dosent it matter the size of piping. (3" or less) once the IC piping if full of air where else can it go. Also FYI since were talking about air and flow, I have 272 cams and 1mm lager intake and exhaust valves.

 

[jdub]

Well, the smallest restriction is going to be your limiting factor for flow...2 1/2" piping is adequate for most turbos (a CT26 would only need ~2"). In your case, the 2" is the limiting diameter. For a CT26 it will be OK, but anything over 60mm (stock size) for the TB is not going to help you.

The piping size needs to be matched to the CFM the turbo is capable of. Otherwise you will exceed critical mach and experience an exponential pressure drop above it....IC piping diameter does matter...a lot. Same for the IC and the TB. They need to be sized to handle the CFM flow the turbo produces for the same reason, big enough to handle the flow, but not too big as to cause a big pressure drop. There is a "right" size for the components of an IC system.

As far as the question at hand goes, a 100mm TB is way too big for your system. The largest I would go is 75-80mm.

 

[92nsx]

.....As far as the question at hand goes, a 100mm TB is way too big for your system. The largest I would go is 75-80mm.

K so 75-80mm for a stock ct-26. Then once my turbo is installed I need to upgrade (chop up me FFIM) again to fit a Q45 or something around 90mm TB, since it will flow more air?

I should ask sethron, or Ron R. if they know that FFIM's with 90mm TB wont work with a ct26.

Seems like a lot of work to just have on a engine for a couple hundred miles to brake it in. Again it dosent need to be perfect just good enough to drive the couple hundred miles to brake it in.

Well maybe I should put the cover back on the car tell this winter, when I install the turbo, EMS and hope I get lucky with a 90mm TB, larger turbo, and hope the code goes away. I just wanted to brake in the engine and make sure problems I might have was not caused by the turbo or EMS, like lets say a broken wire from the TPS witch I would balme on the EMS program if I couldnt get to run on the stand alone.

I thought it would be a lot easer to tune/install/get running the EMS, knowing that every thing was good to go before installing it and know the engine/sensors were ready to go. Kind of know what I mean and/or going with this



So the conclusion to my idel problem and having a code 41 is that the TB is WAY TO BIG, and not sealing correct. Um...ok I guess I can go with that on the idle problem. I am just having trouble seeing why it would throw a cade 41 for the TPS.

 

[Facime]

I dont the think the TB is in any way directly responsible for the 41. As I said before you need to isolate where the problem lies, in the TPS itself or its wiring.

As I suggested before you need to make sure the TPS is adjusted to spec. This means using feeler gauges and checking the resistances. If its not in spec, replace it and re-adjust. If the TPS CAN be adjusted and you still have the code, the problem must be in the wires between the TPS and the CPU (or very unlikely but possible damaged ECU).

When the guy did the motor swap on my mk2 he cut the JDM harness and spliced it into the USDM harness. In doing so he mixed up two blue wires that had the same red stripe. One wire was for one of the ISCV circuits, and the other for the TPS. It took tracing the TPS wires back to the ECU to figure this out. You may not have had any wires spliced like me, but this story is to illustrate that to find the problem you NEED to check it at the ECU connections.

Please try to solve what you CAN solve first, then worry about your TB issues after you have ruled out other things.

 

[92nsx]

^^^ I under stand. Adjusting the TPS is easy as hell, I have done it, check it 1000 times in my life. I have swaped more 7m's in supras' the last 11 years then you probably have owned cars. This is not my first time. How ever this is my first time I have done a swap and had a code, that I can not figure out.

I know that when I spliced in the longer harness, the wires are connected to the right wire. I took a pic . As for the rest of the wires from the harness to the ecu they can not be broken because I check them at the ecu and everything ohmed out correct (post 89, I posted the #'s). I could run 4-10' jumper wires from the TPS to the ECU just to double check.

Is there anything else that causes or could cause this code besides the TPS?

 

[Facime]

^^^ I under stand. Adjusting the TPS is easy as hell, I have done it, check it 1000 times in my life. I have swaped more 7m's in supras' the last 11 years then you probably have owned cars. This is not my first time. How ever this is my first time I have done a swap and had a code, that I can not figure out.

You arent listening
Ive owned more cars in my lifetime than I am years old
Good luck with this

 

[92nsx]

k Facime well if your are talking about something other then a broken wire from the TPS to TCCS OR the TPS not being adjusted right, what else are you trying to say??????? The TCCS is shot? (I can highly doubt that the ECU is shot but wont put it past anyone, again this not been brought up if so.)

So you have "owned" 45+ different cars umm..... what kind of "cars" do you buy that only last 6 months or less? Or are you a lawyer and get to buy a new car ever 6 months? :dunno: If your a lawyer what are you doing with a MKII supra?

Well we now have 105 posts and at least one problem has been fixed

 

[jdub]

An 80mm TB is too big for a CT26, but will work. The Q45 is an 80mm (ID) TB, but has it's own wiring issues with the TPS. You need to have an IC and piping matched to the flow of the turbo, bigger IS NOT better. Focus on the entire system, not just one part of it

 

[jetjock]

Weezl is right. In spite of your 11 years of experience (which appears to actually be 1 year of experience 11 times, (a completely different thing) you should listen to him. Being unknowledgeable about the EFI system (mighty strange for someone whose been around it so long) and possessing poor diagnostic skills can be excused but not knowing what you don't know and refusing to listen while being unable to resolve the problem yourself places your critical thinking skills on par with a mushroom. For anyone seeking advice it's a slippery slope...

 

[92nsx]

Again this is the first time ever using a FFIM, larger IC, and larger TB. All of my experience with my past supras' and 7m, have been direct swap. 7mgte for 7mgte using direct bolt-ons. Greddy TD06,RX-7’s 550's, AFIC, AFPR, exhaust, ect. Just bolt-ons, never nothing this involved when it comes to the fabrication of FFIM's, TB, and IC piping. I just got unlucky on this FFIM/TB .

Also (call it getting lucky) this is the first time ever (besides forgetting to plug in the AFM after a swap) having the check engine light come on.

I appreciate your guys help with everything. Before I started this build I asked the members (did my research) here on the forum regarding FFIM/TB and intercooler piping size. Every one that responded to my IC piping question said to use 2 1/2" on the hot side and 3" on the cold side and the 4" TB would be fine. Maybe this is the "youth" that Greg/Homer was talking about. Any further questions regarding fabrication I think I will direct towards the experts.

As for my next move, I think am going to wate untell the funds are available for my turbo (something around GT37R as long as it is ball bearing), EMS, and entire fuel system. The 12 grand is all but spent at this point of time. I still might try and figure out a way to mount the OEM TB to the FFIM using a reducer that I would make, and smller IC piping and see if it helps anything.

I appreciate your guys help with everything on trying to fix this problem. I see now that I need a few more parts before the engine will be ready to rock n' roll. Sorry if I pissed anyone off on the way, I never meant to.

 

[IJ.]

Good post Rob, remember we're all learning as we go
(no one knows it all, it takes time to learn who is worth listening to here )

 

[need new tires]

have you tried swapping you ISC? i had an issue just like this when i did my n/a-t swap. my car was acting just like yours but it would rev to 3k and then 1k then 3k ect.

the only other time i have seen something similar is when i did a gte swap and the timing belt stretched after first start-up and caused the timing to be off 2 teeth. it threw 2 codes and once i reset the timming it cleared up.


as for the throttle body being the issue i say NO. there is a local guy running a ffim/ q45 on a stock ct26 and has no tunning setup on it ( minus afpr) and he has no issues with it.
-shane

 

[jdub]

Take a closer look at the pic of the TB...it has a significant gap around the lower right edge. It does not completely close...pretty much makes it useless.

 

[need new tires]

^fair enough(i missed that).

his car is still mass air, so even tho it is sucking lots of air past the TB it still should idle, just elevated. correct? its not like a vacuum leak, or is the isc adjusting all the way out and then resetting to cause the sweeping "idle"?

(thinking "outloud")

 

[IJ.]

With that much bypass on the Throttle plate it would probably be close without an ICS.

Might be an idea to unplug it block the port and see how it behaves.
(I run DBW Idle control here and the Throttle is tipped 1% at idle)

 

[need new tires]

thats what i was leaning towrds unpluging both the isc and the tps.

side note:does the ffim have the one-way valve for the isc?

 

[jdub]

He blocked the ISCV air source off depriving it of air. On a stock ECU, that TB is going to cause pretty big idle problems combined with 272 cams.

 

[92nsx]

have you tried swapping you ISC?

The only other time i have seen something similar is when i did a gte swap and the timing belt stretched after first start-up and caused the timing to be off 2 teeth. it threw 2 codes and once i reset the timming it cleared up.

As for the throttle body being the issue i say NO. there is a local guy running a ffim/ q45 on a stock ct26 and has no tunning setup on it ( minus afpr) and he has no issues with it.
-shane

No, I have not swaped the ISC. In the Video (post 66 I think) I unplug it and block it with my finger so no air can come it throu the ISC. Idles ok for about 3 sec then back to same old same old.

As for Q45, umm........... I still think with this TB I have needs to seal better when closed, and let the ISC do it's job.

thats what i was leaning towrds unpluging both the isc and the tps.
side note:does the ffim have the one-way valve for the isc?

When I unplug the TPS the idle shoots up to 3000 RPM's and stays there. I have only unpluged the ISC once (with TPS pluged in) and nothing changed. Should I try it, having them both unpluged :dunno:
And, yes one-way valve is installed. The correct way, let air in and not out

He blocked the ISCV air source off depriving it of air. On a stock ECU, that TB is going to cause pretty big idle problems combined with 272 cams.

plus this OEM ECU probably has no idea what to do with this FFIM, TB, 272's and larger valves.


Side note: I see the "Top Guns" here are running MoTeC. I was looking at the AEM EMS. Is the MoTeC that much better of a EMU, better options, hardware faster, software, support? I am guessing not plug and play like AEM?

 

[IJ.]

MoTeC's strong points are a) it works b) The new software is simply brilliant c) their support is second to none.

 

[jetjock]

All unplugging the ISCV will do is freeze it in whatever position it happens to be in at the time. The same thing will happen if the TPS is unplugged.

When I unplug the TPS the idle shoots up to 3000 RPM's and stays there.

Considering what I just said ask yourself why that would happen...