I am trying to tune my NA 13B, with a E6X. At present, it has less than half as much power as it should. I have a Mindtrain header on it, and if I take it for a drive on the highway, when I stop and look at the header at night, the header tube going to the rear rotor is glowing red, while the header tube going to the front rotor is not glowing.

I have checked the timing many times, and it is spot on. The trailing and leading wires are all hooked up correctly (checked and triple checked). I am running a DIY WB, which is on the header tube that is glowing. Other than reversion back up the header from the collector, the WB does not see the cold header tube. The WB is reading anywhere from 12.0 - 14.5, depending on the load, etc.

I checked the compression, and I am getting even bounces of 95 psi on both rotors, all faces.

One thing that I haven't checked yet, is the injectors. I am wondering if a stuck injector would give me the symptoms that I am seeing. It starts very easily, and idles well.

Has anyone seen these symptoms before, or have any idea what is going on?

Thanks for any help.


Greg

 

I would have the O2 sensor checked and recalibrated. My last o2 sensor that went badd only read 14.2 -14.7.

 

Get an EGT gauge.


-Ted

 

I have an EGT probe. I will pull the WB, and put in the EGT probe, and get a reading. This is just a temp setup, otherwise, I would have both readings at the same time.

Thanks,

Greg

 

Depending on how close you have the wideband sensor to the exhaust port it's likely you are overheating it which will shorten it's life and skew your readings. Would be best to install the sensor after the collector then have an EGT probe in each primary. Tune the mixture for a composite of the two rotors then use EGT to balance the mixture between the two.

That still doesn't address your issue though. You don't need an EGT probe to see that one rotor is running much higher EGT than the other in this case. I would check timing on all four plugs in a dynamic state. Meaning loaded on a dyno. At that point if it all checks out it's down to fuel so start by having the injector checked out.

 

Thanks for the replies. I agree that my setup with my WB and EGT is not optimum, but this is just a temporary setup. I understand that garbage in equals garbage out, so I am taking my results with a grain of salt. I am currently running my N/A engine, because I did not have the time to rebuild my 13BT engine.

I agree with what you are saying C. Ludwig. I don't need an EGT probe to tell me that one rotor is running hotter than the other. Unfortunately, I don't have access to a dyno, so I think I will try the injectors. I will physically pull them out, and check the spray.

Greg

 

For the time being, switch front and rear injectors. *on engine flow test*

Much faster then shipping them out for a test

 

Actually, I am going to pull the injectors, wire them into the fuel rail, and visually check the spray on them. I am running the TII injectors on it (550's), and for simplicity, I don't have the secondaries coming on line (NA). I can always just switch the primaries and the secondaries to check it, as well.

 

Good idea!

 

OK, just a quick update. I just used a pyrometer to measure the difference between the front and rear rotor. After idling from a cold start for 5 minutes, the front rotor exhaust was showing 165 deg F, and the rear rotor was showing 915 deg F. It was idling around 2500 RPM.

On to the injectors...


Greg

 

2nd update... It appears that one of the wires came out of the front primary injector clip. I basically just left it until tomorrow, when I can see better... darkness set in too fast!

Greg

 

Well, turns out it was the loose wire. So, it appears the car was running on one rotor. Funny that it started and idled fine! Now, there is a light glow coming from both header tubes, at night!

Thanks for the help!

Greg

 

Visually checking the spray will not help, even clogged injectors can look like they are flowing good, if you dont have something to measure this flow it does you no good.

If you're only getting one of the exhaust runners glowing it simply means that rotor is not getting the same amount of fuel as the other one, dont think about it, take your injectors and ship them out to get flow tested, cleaned and balanced, period. No sense in loosing an engine from having unmatched injectors or dirty ones.

When ever i take on an installation i always have the owners of their cars either send the injectors to get cleaned before we start or have had them cleaned a short while before we start, and make sure the fuel filters are new. I've had cars that literally died on me cause the injectors just clogged up all of a sudden, but that was worst case scenario where the owner actually had me riding around in the car with no fuel filter on.

 

Good information, Claudio. I figured at this point though, it wasn't a matter of the spray being a little bit off. A graduated cylinder, stopwatch and pressure gauge works well, to tell if you are getting the proper flow.

The injectors were done about a year ago, so I figured they should be okay. Luckily, it was just the loose wire on the front primary injector!


Greg