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"Most consumer grade widebands are just rebranded Bosch LSU 4.2 widebands.
It's also what I currently have in my car just monitoring with a gauge. I am going to be upgrading mine to a production grade NTK which will be much more accurate; even after 500hrs. It's long since been used by tuners and was difficult to find and very expensive until just recently. It can be found under the AFR500 name plate."
i one thousand percent agree w the above and use NTK widebands. the Bosch 4.2 need re-calibrating very often and doesn't read well in the 10 handle.
as per Zoom Zoom the NTK setup is currently available as AFR500.
Most of the stuff I've read about the innovative wideband is that after 500hrs it loses the accuracy you would want. The tests I've seen show .5 AFR swing. So if you tune for 11 it could be 11.5 or 10.5 AFR. Actual. Most consumer grade widebands are just rebranded Bosch LSU 4.2 widebands.
It's also what I currently have in my car just monitoring with a gauge. I am going to be upgrading mine to a production grade NTK which will be much more accurate; even after 500hrs. It's long since been used by tuners and was difficult to find and very expensive until just recently. It can be found under the AFR500 name plate.
It's probably not likely to be the problem that caused your motor to blow as you were not using it. But there isn't much point of upgrading an ECU if it's being given less than accurate feedback readings to tune by.
Good luck and sorry to hear about your motor. I have felt that pain too many times.
I've noticed this as well as I've had to install more than one wideband when I had the innovate setup. My innovate setup always had quirks. I had to use heat sinks. Sometime when I got heavy on the throttle, it would lose signal occasionally. I also got tired of doing the calibration. Ever since I installed an AEM unit, I've had zero problems. Plus you don't have to calibrate them amd I was able to remove the heatsink.
I know this is a bit of a derail, but if you go with a different wideband controller than Innovate but wanted to log egt's or fuel pressure also, what are the options? Only thing I can figure is use the Innovate analog module to log the 0-5v output from another brand wideband and convert back to AFR inside the adaptronic. This seems like a step back however since a serial digital signal should be more accurate communication to an ecu than a sensor reading converted to digital inside the wideband, then converted to analog and back to digital for the ecm to read. Am I wrong?
You ask: What Happen?
Rotary Murphy's Law
Open the engine, find what failed and then find the possible causes from there.
Common sense dictates, it easier than diagnosing prior to that, with so many variables.
It's funny because I had the AEM UEGO and sold it to get the innovative unit for the plug n play feature of the adaptronic. I never had a problem with that thing, I'm now considering selling the Innovative for another...
Im assuming this car is making around 12-13psi to achieve those horsepower numbers. It just seems like regardless of the brand or calibration, if its anywhere between 10.5AFR to 12.5AFR, it can't possibly be that catastrophic to blow the engine from running slightly lean. Still sounds like a timing issue, or MAP reading as mentioned earlier
"Most consumer grade widebands are just rebranded Bosch LSU 4.2 widebands.
It's also what I currently have in my car just monitoring with a gauge. I am going to be upgrading mine to a production grade NTK which will be much more accurate; even after 500hrs. It's long since been used by tuners and was difficult to find and very expensive until just recently. It can be found under the AFR500 name plate."
i one thousand percent agree w the above and use NTK widebands. the Bosch 4.2 need re-calibrating very often and doesn't read well in the 10 handle.
as per Zoom Zoom the NTK setup is currently available as AFR500.
The model that was so popular with tuners was the NTK Powerdex. It was discontinued and replaced with something different. The only way to get the NTK Powderdex is to buy the AFR500 which was created by the original Powerdex manufacturer. You can read more details on Ballenger Motorsports website.
If you decide to buy the AFR500 be sure to upgrade to the Production Grade NTK sensor. They package it with the Bosch 4.2 LSU in the base package. $50 upgrade gets you the NTK sensor you need with the AFR500 controller to get the best wideband for the money on the market right now according to many who are better informed than myself.
I purchased mine with the optional shorter 7 foot harness vs the standard 13 foot as mine will be "in car".
Hey guys, sorry for the hiatus. Lots of great comments here. Appreciate the help from the community. The car is almost back together now w/ some new goodies. If you're going to throw money at it, you might as well throw a lot of money at it... I guess...??
Upon pulling the engine apart, it was apparent that both rotors blew an apex seal. That narrows things down a bit. Clearly a no fuel issue rather than something going bad with a particular injector. I probably should have checked this sooner, but it wasn't until we tried to get the car started with the rebuilt engine that we noticed that the fuel pump was still not getting voltage. Eventually traced this to a bad EGI relay. Fuse was ok, but relay was dead.
So couple questions:
1) The EGI relay suddenly going bad can cause the engine to self destruct? That seems a bit crazy (by design). No EGI power means no fuel pump which is obviously a big problem, but there's also the EGI fuse and fuel pump fuse that could potentially go out. I can't imagine if any of those go out it means goodbye engine. Is the ignition somehow connected to this circuit such that if the fuel pump loses power ignition stops firing? Seems like that might save the engine. So I still don't understand why I lost the engine.
2) What can cause the EGI relay to suddenly fail? Just bad luck? The fuel pump relay was jumpered into high voltage mode at the dyno. Could this have somehow impacted it? I still question why this was even necessary because even with the jumper it still wouldn't get around any voltage drop issue in the stock circuit wiring. Only seems like it would help if the fuel pump high voltage relay died, which it hadn't. As a reminder, the car had many full range pulls on the dyno, afrs looked great. Only when taking it on to the highway did it let go on maybe the 2nd pull.
I'm rewiring the fuel pump and installing a new EGI relay, but still not fully confident that we've solved the issue w/o knowing exactly what went wrong.
Btw, here's the wiring diagram. I follow the fuel pump / relay wiring, but get a bit lost with the EGI wiring. I see a line from the EGI relay going over to the ECU, some "solenoid" and "el unit". Maybe the ECU knows to cut ignition if this line goes dark? I'm running the Adaptronic PNP. Hopefully that logic is built into it. Can anyone confirm? It also looks like that line enables triggering on the "A/P relay" which looks to be part of the A/C system.
It doesn't appear that the EGI relay controls the fuel pump relay. The power to close the circuit opening relay is jumpered off BEFORE the EGI relay and then grounded by the ECU. According the the circuit wiring I am unsure how a bad EGI relay could cause the fuel pump not to run, although it would cause the injectors not to fire.
It doesn't appear that the EGI relay controls the fuel pump relay. The power to close the circuit opening relay is jumpered off BEFORE the EGI relay and then grounded by the ECU. According the the circuit wiring I am unsure how a bad EGI relay could cause the fuel pump not to run, although it would cause the injectors not to fire.
Ya good point. I thought about what I wrote afterwards and it didn't quite make sense. Is it possible that the egi relay failing could pull the trigger line down and also cause the circuit opening relay (provides power to the fuel pump) to trigger off since they're on the same line? You're right in that an egi relay failure should have caused the ignition to fail which I would think would have prevented a lean condition. I'm grasping at straws here...
I think the egi relay malfunction disabled your injectors, causing the lean condition. The coil packs derive their power directly off the ignition switch and then triggered from the ecu. I think your root cause is correct, but the assignable cause is the injectors failing to fire instead of the fuel pump. If the egi relay failed in such a way to draw down the voltage I would think you would have blown the 15a engine fuse, was it blown?
I think the egi relay malfunction disabled your injectors, causing the lean condition. The coil packs derive their power directly off the ignition switch and then triggered from the ecu. I think your root cause is correct, but the assignable cause is the injectors failing to fire instead of the fuel pump. If the egi relay failed in such a way to draw down the voltage I would think you would have blown the 15a engine fuse, was it blown?
I went over to the shop today to take a look at the car first hand. Trying to debug the car via second hand information wasn't working very well.
So turns out the only issue was, as you said, the 15A engine fuse was blown. The egi relay was fine once the fuse was replaced. I think your theory is sound. Engine fuse went out, therefore injectors didn't fire, engine went lean. What kind of insanity is that? Fuse blows and the engine is toast? How can it be designed like that? Feel like I'm missing something here. Why is a 15A fuse needed to just trigger a couple relays anyway?
I have no idea, but I think a better circuit design would tie in another relay to that fuse that, if the fuse blew, would drop power to the coils and the ignitor, thus shutting down the engine and preventing that lean condition. I can only imagine how many engines have been blown because of this very problem. I think I will fix this on my car, I should sketch up a schematic and post it for others to critique. I am no expert on rx7's but I am a service engineer for Cummins by trade so I have to deal with poor circuit design and software on a daily basis.
I am in the process of upgrading my fuel pump, fuel pump wiring including a 40a relay and inline fuse. The stock wiring, relay, fuse etc aren't up to the task of handling all of the amps the bigger pumps are drawing under higher pressures.
I have the parts and am in the process of documenting the install in my build thread if you want to see the process.
I am in the process of upgrading my fuel pump, fuel pump wiring including a 40a relay and inline fuse. The stock wiring, relay, fuse etc aren't up to the task of handling all of the amps the bigger pumps are drawing under higher pressures.
I have the parts and am in the process of documenting the install in my build thread if you want to see the process.
I'm using the supra pump. Would the current draw on the pump change as you're using additional fuel? I figured the current draw would be constant at a given voltage. The pump flows at a certain rate at a given voltage. I wouldn't think this would change as the injectors draw more fuel.
But, in general, I agree, it's very likely I over taxed the stock wiring and caused something to pop. Stupid on me for not rewiring the pump beforehand. Expensive lesson to learn. Not to pass the buck as I should have better understood what was going on at the time, but the shop gave me the silly fuel pump relay jumper and I assumed somehow that guaranteed battery voltage to the pump.
I have power to the pump wired directly from the starter positive terminal (goes straight to battery +) now w/ a relay triggered by the Adaptronic turning on. Hopefully that's bullet proof.
Here's a simplified version of the wiring diagram for the fuel pump, with some color added to highlight how certain fuses and relays affect the distribution of power:
Btw, here's the wiring diagram. I follow the fuel pump / relay wiring, but get a bit lost with the EGI wiring. I see a line from the EGI relay going over to the ECU, some "solenoid" and "el unit". Maybe the ECU knows to cut ignition if this line goes dark? I'm running the Adaptronic PNP. Hopefully that logic is built into it. Can anyone confirm? It also looks like that line enables triggering on the "A/P relay" which looks to be part of the A/C system.
if you look at the switched side of the EGI relay, it does four things.
1. it powers the injectors, the ecu grounds the injectors
2. it powers the ecu, pin 2b.
3. it powers the air pump relay, if you still have it
4. it powers all the other solenoids on the engine, like the BAC valve, and the solenoids if you still had them
the coil side of the relay gets switched power from the ignition switch, through the 15A engine fuse, and this wire also powers the fuel pump relays and ignition. the actual fuel pump power is a different source.
if the switched side of the EGI relay failed on a stock car, its likely it would just stop running (you can have the car idling and remove the relay and see for yourself). it is possible that in a modded car at full boost something bad might have happened
02-23-16, 07:03 PM
Why is a 15A fuse needed to just trigger a couple relays anyway?
