SDL with new hyperflows, new rear o2 sensors, changed oil and reinstalled right temp

Out for a rude. Something' is wrong with left Tc. Hung around at .7! When other was as 2.7. After 5 miles it finally went to 2.4. I'm going to replace that Tc. Going to try and rig egt one. It's $60. Have to get the right size but for it.

 

Yes Tim. If you poke around omega site and look at their connector offerings they big a huge deal out if this issue.

The vesci units use amp auto pins in the Tc end and who knows what on the circuit board.

I would suggest anyone who wants if cares to know what your ecu is seeing. Get some positaps, install them on your signal lines, run leads off them to your cabin and drive around with your Dvom and see what's going on. Mine were a mess and one side is still odd.

 

50 miles. No sdl and zero codes. All voltages pretty much settled out around 2.80.

I'm going to clean up the install and leave it in place and keep monitoring the voltage on startup.

Egt is going to look into seeing if they can tune the board to get .55 or so on startup. I wonder if it's that when it's cold out also

 

I'd like to hear from a tech who knows for sure if the cat temp affects the mixture via the motronics or is all this just to warn of overheating cats? I think it does and if it does that cold voltage level to start may not be ideal

In thinking about my errant tc on start up earlier. It may have been because I did that connection in my house and on plugging it in the temp,differential between the two pieces may have needed to equilibrate ?? Seems consistent now.

Connectors and egt probably cost about $75 as is. I need to get the correct amp ends for the tc but I've found them for about $4 each. Long ways from $375 anyway. If we are happy with all this we can talk to egt about terminating the ends, etc. and selling it as a plug and play also. A good find John. It does need some road time before we call it success but it looks good. Pouring compound in the box might be a good idea as well.

 

Rifle driver. Are you here??? Are we dealing with anything on these voltage transmitters beyond cat protection? You guys that have been around these things for 20 years must know.

 

I had a chat with someone who probably knows this answer. In his opinion there is no fuel trim relationship and it is just a warning system. Although he is also unsure of what all the componentry in the OEM ECU is doing.

I am going to get a few of these and makes up a little console and keep the positaps in place and run them through the firewall and watch this for awhile.

0.36 0-33V Voltmeter - Shop Cheap 0.36 0-33V Voltmeter from China 0.36 0-33V Voltmeter Suppliers at RD FACTORY on Aliexpress.com

 

Revisiting this thread...

The EGT units have been in the car for a month now and seem to working well. I still have the positap leads in place and monitor the output voltage regularly.

I had an issue with one TC and blatant intermittency that would throw blinking sdl, solid sdl and finally limp mode. All of these would self rectify in short order, I had switched the TC frm side to side and the issue travelled with it.

I had been working on sourcing an alternative to the absurd $300 Ferrari TC and now say I have got it figured out. Your cost for a new TC will be $70 and will require a $2 plug and a drill and tap of the compression nut that comes with the TC. Easy to do. The length will be correct both for the TC probe and the braided lead.

I am going to replace my other 2 TC as above and will then have them all replaced.

I am still getting a 1449 and a blinking sdl in conjunction with it. I can clear this code and the sdl goes away as well. THe left side, which is the 1449, has the egt transmitter and an original TC. I am going to get the new TC and see what happens with the 1449/sdl.

In checking the voltage outputs I am not confident that the Bypass valve one is working properly. WIth the car fully warmed up and driving, the cat voltages are over 2.xx volts and the middle one is .5 - .7. This one has a Viscovini ecu on it (a black one) and one that I had previously determined to be working properly. Maybe a new TC will help there as well.

If anyone wants to get any of this stuff, let me know and I'll write up the details how to put it together.

 

Will do Carl.

I just ordered a third transmitter and two more TC spec'd to replicate the OEM ones as far as length/bend , etc. I will install all the new parts and run it for awhile so as to have some test time on it.

I have picked out a potting compound as well and will encase the circuit boards in the boxes like the OEM is. I'm going to use the OEM connectors on the TC although they may not be the best as per the TC industry but it will allow anyone doing this to plug and play the components with the OEM parts if desired.

 

They said up to 185 degrees it isnt necessary and they have only done it a couple times due to vibration issues. I am thinking that 185 is breached in our application.

Routing everything to the ecu compartmnet would be ideal and again is doable but it would require a fair amount of effort in figuring out how to route the TC leads and the signal wires through the firewall. I suppose snaking them through the main harness hole would be the way but I am not sure you can even see that with the engine in.

Thats another design to consider. They have a 4 channel unit so you would only need one power supply and one box. Just need to tap the signal wires in the ecu compartment or plug into them in in the engine bay and run them back to the ecu with the TC leads.

 

Steve this doesn't eliminate the system it is alternative to the OEM absurd prices. If you wanted to bypass the system and not have the safety factor it all , I would run a 1.5 v source through the cat ecu signal wire. I'm not clear on the bypass valve tc and it's function in all this. It tells the ecu whether the valve is open or closed according to the temp thresholds built into the ecu. What it does with that info I am unclear or if it plays into sdl.

 

Interesting data point. I switched the assemblies ( egt unit/tc) from side to side as a unit. In monitoring the voltage outputs before the switch the left side was outputting around 2.7v at full temp and the right around 2.2. The left has an old OEM tc and new egt box, the rt had a new egt tc and box. After the switch the voltage disparity switched as well.

At 2.7v , that tc/ transmitter is close to tripping that 3v trigger for an sdl. Note that the fresh tc/box combo is running at 2.2 on both sides, so it isn't an engine thing, it's the sensors.

I was getting a 1449 , left side cat out of range, cel and sdl. It will be interesting to see if that becomes a right side same cel.

I think that the ecu wants to see these voltages in sync as well as peak threshold triggers as far as sdl are concerned. I am also thinking that these tc get tired,heat affected , etc. and that they may be a big cause of the intermittency that some experience with sdls.

Fresh tc @ $80 a throw may go a long way towards rectifying some of the voltage variations creating these issues.

 

John. Both sides have the egt boxes. No OEM ecu. Only difference is the 2.2 side has a new Tc and the 2.7 side is an old OEM one.

It is the Tc causing the disparity

I watched both sides from cold start also today. One was around .26 the other .3.

 

Right Tim. I have a positap on the center one as well and it doesn't move much. The cats are at 2.xx and the center is at .55. If I gun it and open the bypass valve it rises to ,68 or so and that's all I have seen. I am not sure what the main ecu does with the info from the center one. Other than barelyt telling if the bp valve is open.

I ordered another egt unit for the center as well. Then I will,have all new tc and egt transmitters only.