Race Ready 7M

[thedave925]

Van,
Is there any reason your still using the ct 26? Bracket racing or the such?

The 7m will feel much different after enlarging the turbine housing even a little bit.

Find someone local with a larger bolt on affair to try out.

 

[Van]

Van,
Is there any reason your still using the ct 26? Bracket racing or the such?

The 7m will feel much different after enlarging the turbine housing even a little bit.

Find someone local with a larger bolt on affair to try out.

Eh... Lack of dough. Household income is below 50% of where it was during the winter of 2009. My plan was to purchase Driftmotion's 60-1, T4 turbo and exhaust kit; BC 264/264 cams; a standalone ECU and get it professionally tuned. That's all on hold for the forseeable future. Van

 

[Van]

I and VIP Performance have not been able to diagnose the cause of the following symptoms w/ this 7M:

As it stands now, the 7M is having a misfire condition during accel on WOT runs, but there isn't any audible knock. The Dyno runs show that power is being lost. This 7M is currently running A/F between 10.2 - 10.5 above 3800Rpms. We have tried new plugs, changed the gap as far down as .20. Re-gaped the CPS pick-ups tight, to near the bottom of their range, new coils and plug wires. The only part not new is the igniter, but it is in spec., and has an extra ground wire.
The 7M also has a misfire condition during idle, that occurs from time to time, in a random pattern, and is likely connected to what is occurring during accel in WOT too. Very annoying!

We have used two different TCCS ECUs, CPSs and AFCs w/o resolving the problem.

VIP managed to seal up the cam covers so there isn't any oil leaks on the plug wires.

No exhaust gases in the coolant, using a Snap-on hydrocarbon detector.

No codes stored in ECU.

By the time Wryan and I solve the problem, he and I will know more about the 7M and the systems in the car, than we ever expected.
If you have any insight into the problem, let us know! Van

 

[CajunKenny]

In my experience, tighter plug gap = worse idle. Are your plugs still indexed?

It sounds like the only thing left is wiring, Van. You can try to narrow it down wire by wire by checking resistance from the ECU to that given component. It's hard to detect intermittencies that way. A better way (not easier) would be to run a wire from the ECU to the component and see if there is an improvement. Example: ECU to the CPS.

I'd start with the CPS wiring...

 

[mecevans]

I added extra grounds to everything and it seemed to help. I have a slight miss at idle which I believe is the ignitor. It only occurs when hot so im going to take the heat gun to each component one by-one with the engine cold. Next step will to scope everything at the PCM.

 

[Van]

In my experience, tighter plug gap = worse idle. Are your plugs still indexed?

It sounds like the only thing left is wiring, Van. You can try to narrow it down wire by wire by checking resistance from the ECU to that given component. It's hard to detect intermittencies that way. A better way (not easier) would be to run a wire from the ECU to the component and see if there is an improvement. Example: ECU to the CPS.

I'd start with the CPS wiring...

No indexed plugs. Back to stock ND Platinum, gapped to .030. I fattened the A/F up a little at idle, by adjusting the FP from 40 - 42PSI, and the idle mis is all but gone. I'll wait another day to try another run on dry roads, to see how well this 7M pulls.
I do have that newer CPS, that I can try. It bench tested WNL, as did the current one on the car.
I know nothing of wire and electronics, so I'll likely pay a pro to do what you suggest.
I remember JetJock sugesting I look at the secondary wave form, to help determine which cylinder is having the misfire. Any idea on how to do what he suggested?
Thank you, Kenny. Van

 

[CajunKenny]

I don't recall, what fuel pump are you running? If you're still at 7psi of boost, then your fp rises to 49 psi at full boost.

In order to take the measurements Jetjock suggested, you'll need an oscilloscope (aka: o'scope). The measurements can be taken two ways: While on a dyno and/or while driving. While driving requires the use of a battery powered o'scope. Too bad we aren't closer because I have both...

 

[Van]

I don't recall, what fuel pump are you running? If you're still at 7psi of boost, then your fp rises to 49 psi at full boost.

In order to take the measurements Jetjock suggested, you'll need an oscilloscope (aka: o'scope). The measurements can be taken two ways: While on a dyno and/or while driving. While driving requires the use of a battery powered o'scope. Too bad we aren't closer because I have both...

The 7M is using the Denso, Supra TT pump that flows ~280LPH.
I'm running 10PSIG.
Kenny, thanks for the tip on the "O" scope. There is an outfit near my home that may help me look at the secondaries... Van

 

[Van]

Here is the latest on Race Ready 7M:
I took the Supra over to Auto Electric Specialties in Milwaukie OR, Friday, and the O scope indicated there was still some intermittent poor signal strength on the CPS. They put on the other CPS I brought, tested the signal, it was more consistent and the misfire condition was gone! The idle was smooth and acceleration showed no misfire, under load. They took off the cover of the replaced CPS, it had a small leak from the oil seal and there was enough oil in the CPS housing to cause a poor signal. I hope they are right... :icon_frow
In the past, I was told the problem was solved, only to have it crop up again, for another reason. Last week I drove the Supra around, and the idle is smoother, never a mis and so far acceleration is also smooth.
Two weeks ago I took the Supra down to the 7Ms builder, Brian Riley (M&B Cylinder Heads), to demonstrate the results of his labor, and it had just started to misfire. He just smiled and said, "still haven't sorted out the misfire..." :nono:
This week I'll drive the Supra around, then up to the Centralia M&G. I'll see if the problem is sorted out by then.
Van

 

[rwdanthony]

hope everything gets squared up.

 

[Van]

hope everything gets squared up.

Me too!

 

[Van]

Good news! From the combination of a "correct" timing and the CPS installed that stays dry inside, my ignition problems are resolved. Thanks to Wryan at VIP Performance, for being so patient.
This 7M is so different from what Toyota designed that using the TCCS, just isn't going to work well controlling timing. In that vein, I was at the Centralia M&G on May 14th, and bumped into Cajun Kenny, who told me that he has a version of a MaftPro, that is using firm ware to provide the MaftPro timing control. That said, Kenny is moving to an AEM. I may also go this route. In fact, I'm waiting for 3P, Jon Sol and a few others that are working on allowing the user to read, log and make adjustments to our TCCS. When that becomes a reality, I'm planning on getting the 7Ms TCCS modified.

 

[CajunKenny]

Just for reference Van, here are the isolation related readings on my car.

Rad to Negative Battery Terminal = 1.1 Meg Ohms of Resistance
Coolant in Rad to Negative Battery Terminal = .18 Volts which is 180 Millivolts.

I'd like to see ~50 Millivolts. So, I've got some investigating to do of my own. I think it's my third gauge; but, anyway...get the resistance as high as possible and the voltage as low as possible.

 

[Van]

Just for reference Van, here are the isolation related readings on my car.

Rad to Negative Battery Terminal = 1.1 Meg Ohms of Resistance
Coolant in Rad to Negative Battery Terminal = .18 Volts which is 180 Millivolts.

I'd like to see ~50 Millivolts. So, I've got some investigating to do of my own. I think it's my third gauge; but, anyway...get the resistance as high as possible and the voltage as low as possible.

Hey Kenny,
Thanks for the continued interest in helping me... I think I understand what you mean by getting the resistance to current flow high and keeping the current flowing into the Radiator, as low as possible, to minimize electrolosis. Is that right?
Right after I returned home, I installed grommets to all the connections on the hold down bracket.
I have a multi-meter (all readings listed are corrected; black terminal to Bat-). I used the following scale 200 Ohms and the result: 2.1 Ohms on the shroud and 1.7 ohms on the surge tank.
I used 200m V scale to check for current in the coolant, result: 2.8m V .
Are those numbers w/i the norm?
Thanks, Kenny. Van

 

[CajunKenny]

Glad to help Van.

Can you double check the reading between the coolant and the negative battery terminal?

If the 200mv scale is the smallest your meter has then that's the correct one to use. Also, make sure the battery in the meter isn't low. I can't tell you how many times that's got me over the years...

 

[Van]

Kenny,
I rechecked the coolant and the result was a negative value, -85m V. The surge tank has 5.8m V. So, here is the problem... I don't understand what it is I'm doing!
I'm going to put the Koyo Racing Rad back on with the custom Aluminum copies of the stock hold down brackets, that use the stock rubber isolators. It works OK and as I'm not racing the 7M these days, it will work well to keep the motor cool.
How is your quest for lower millivolts going? Van

 

[CajunKenny]

Your readings of 2.1 and 1.7 ohms are what I would expect to see given your current setup. Basically, your radiator is a direct short to ground which makes your rad an electrical path for stray electrical currents. As mentioned, the factory setup completely isolates the rad from ground to prevent damage. Rads with plastic end tanks were ideal for isolation. They fell short in other ways, however...

What doesn't jive is your low millivolt reading. Low resistance (2.1/1.7 ohms) should read higher voltage.

When you just mentioned your koyo rad, it reminded me that your current rad doesn't have a cap so you can get readings from the coolant there. Taking them from the overflow tank isn't a value that were looking for.

Based on your resistance readings, I know that your rad is shorted to ground. We need that value as high as possible. Higher resistance means less current flow.

While changing out the rad isn't a difficult job, it is a messy one. You might try to isolate the current rad instead of switching them out.

Try this! Unbolt all the fasteners/braces from the rad and let it sit free in just the lower rubber grommets only and take another measurement between the rad (somewhere unpainted) and the negative battery terminal. It should read in the Meg Ohms. If it does, that proves that the top bracing is indeed where the problem is.

 

[Van]

Your readings of 2.1 and 1.7 ohms are what I would expect to see given your current setup. Basically, your radiator is a direct short to ground which makes your rad an electrical path for stray electrical currents. As mentioned, the factory setup completely isolates the rad from ground to prevent damage. Rads with plastic end tanks were ideal for isolation. They fell short in other ways, however...

What doesn't jive is your low millivolt reading. Low resistance (2.1/1.7 ohms) should read higher voltage.

When you just mentioned your koyo rad, it reminded me that your current rad doesn't have a cap so you can get readings from the coolant there. Taking them from the overflow tank isn't a value that were looking for.

Based on your resistance readings, I know that your rad is shorted to ground. We need that value as high as possible. Higher resistance means less current flow.

While changing out the rad isn't a difficult job, it is a messy one. You might try to isolate the current rad instead of switching them out.

Try this! Unbolt all the fasteners/braces from the rad and let it sit free in just the lower rubber grommets only and take another measurement between the rad (somewhere unpainted) and the negative battery terminal. It should read in the Meg Ohms. If it does, that proves that the top bracing is indeed where the problem is.

Kenny,
I think I understand; electricity follows the path of least resistance... More resistance is what I need. Then how do we achieve it?
I noticed the Able radiator had a wear mark on the pasenger side end tank, that was pressed up against the piece of aluminum I am using as a deflector, of hot air from the Rad fan.
Tomorrow AM, I'm going to test the Koyo Rad for current and resistance and post up the results here. Van

 

[Van]

The new values on the Able Rad are: 1.87m V on the Rad (chassy is 5.9 m V); 3.79mV in the coolant. Van

 

[Van]

Here are the values for the Koyo "Race" Radiator: .002mV and 1242 Ohms; Coolant in Rad: -0.17mV (all done w/ignition on). I tested the Rad w/o the ignition on and the mV values were so low: -12.0mV.
Again, I'm not sure what these values mean for the life of the Rad. Are these values ideal? Van