It might be a Hyperterminal thing, I dont know... I will get an answer to your question here shortly..

I will do a idle log here later on this morning.. Have a few meetings to take care of then I am free..

K

 

K

You got a pm..

 

I do? It didn't come through, I got nothin!

 

lol.. had to type it..

 

lol, sorry.

I got an Email from TurboXS saying that it is very possible that my flywheel is causing the RPM to jump. The Email also stated that they had a test car with a flywheel and the RPMs jumped around a lot, making it a complete nightmare (sounds familiar).

Still no hesitating though, so that is good.

 

Hey Kev..I have gone out of my way to be helpful to you despite you taking shots at me on a continuous basis...Im done feeding into your threads, good luck, I wish you the best on your tune..It amazes me we have never had the issue you seem to be having..I thought Sharif put your car together and tuned it?

 

You've gone out of your way to be helpful? You continously talk down every UTEC user that wasn't tuned by MRC.

From what I've read on here, its pretty amazing you have installed and tuned as many UTECs as you have and you have yet to have a defective unit. My first one was defective, and I've read other threads on here about the units now working right out of the box.

Sharif had nothing to do with my car, other then arranging the GB that I bought my rods and pistons from. I've also bought spark plugs from him. My motor was built and installed locally with the TT kit and other parts I bought from Scott Performance. As stated above, I bought my UTEC (and injectors) directly from you. I've done all the tuning myself, with help from a few people on here (the timing side). Unfortunately, in Dayton, Ohio, there arn't many shops within reasonable distance. I had a 'remote' shop do my first round of FI (Procharger) and I personally didn't like having a shop that wasn't within driving distance of my working on my car.

It really just kills me that you talk to the UTEC up to be perfect. It has had MAJOR bugs in it, and there have been several DOAs reported. It has came along way since it's release, but there are still things that can be fixed in it. No matter what shop installed it or tuned it some of the issues I have had (boost controller not working till 2.8d, hesitating (bad unit), grounding issue (internal ground issue), etc) were unavoidable.

On a final note, tuning a VQ35 isn't rocket science, nor is installing a UTEC (unless it is in to a G35, retains the OEM ECU bracket, and all panels fit back on when you're done).

 

I talked to another shop owner for a few minutes tonight and may have made some progress on the jumping RPM. At this point, I think the car has always had this problem, but I never realized it until I started watching the RPM on a digital display (the analog needle doesn't pick it up). The 'problem' was most likely created when the flywheel was installed, and will hopefully be fixable with a little work. The thing is, is it never threw a code, and it has always revved smoothly, so there was never an indication that there was a problem.

At this point, my fingers are crossed and I hope this is the solution....

 

Hi there,

I also had the same type of problems with Kpierson. I've tried every possible method listed above including replacing UTEC with a new unit, F-Con Pro.

Really stop blaming users being noobs about tuning and stuff, UTEC is a nice toy to play with but it has serious bugs, admit it.

 

Do you have a lightweight flywheel?Some of the light weight flywheels cause a scattered crank signal to the ECU.Not really a problem with the UTEC, as much as a combination of incompatible parts..A small washer on the Crank position sensor fixes the issue..

 

nope,
my issue was solved the day i replaced UTEC.

 

Kind of off topic, but I was talking to another UTEC owner who's UTEC failed while he was on Tail of the Dragon this week. Had to have the car towed back up to the village to work on it, and that is what they found. Talking with other people while at Zdayz I got the impression that almost everyone has at least one issue with their UTEC, even if it is minor.

 

I'm really thinking hard about swapping in a Megasquirt................

 

I have no experience with Megasquirt. Used UTEC on my WRX and then upgraded to AEM. Started again with UTEC on my Z and upgraded to F-Con as HKS dealer here is a friend of mine. I must say that UTEC is a good platform up to a certain degree of modification. I had to play with cam timings and stuff like that after some of the modifications listed in my sign and it was impossible to do with UTEC anyway. Using UTEC after some level is doable but well probably isnt the best thing to do and yes it has some bugs.

 

OK, I talked to a VQ35 shop owner/tuner over the weekend and we discussed shimming the crank angle. It fixed a similar problem on a car that he was having. So, I shimmed the sensor when I got home and found out some things.

1. The UTEC gets it's RPM signal directly off the crank angle (no surprise here)
2. If the crank angle sensor fails (or comes unplugged) the car WILL NOT START. This is different then the OEM ECU. If the crank angle sensor fails with just the OEM ECU the ECU will use the cam triggers to run the motor and switch to batch firing, so at least the car is drivable. This is very nice to know for future reference.
3. Shimming the crank angle did absolutely nothing for my RPM readings.

Here is a graph of RPM from my Cypher logging tool and from my UTEC. The Cypher actually reads at a faster rate then the UTEC, but other then that both logs were done at the same time (the very beginning of the graph was my 'alignment' point where you can see both graphs spike). I then let the car idle for a few seconds and this is what I got:



I'm not sure if the Cypher is reading a filtered ECU signal or not, I would have to unplug my UTEC to find out for sure, and I'm not interested in doing that right now. I'm left wondering now if A. The cypher is reading a modified RPM signal or B. The UTEC doesn't read RPM as smoothly as the OEM ECU.

 

The stock ECU also recieves its RPM signal directly off the Crank
And if the Crank angle sensor fails on a car NOT equiped with a UTEC it will also not start.
This is nothing new.
However the RPM and timing should NOt be altered by the UTEC at idle or off load..Have you tried unplugging your UTEC?

 

Are you sure it won't start? The service manual says it will. I've never personally tried it, but I think I've read threads on here about it. I believe you have to crank for at least 10 seconds and it will throw a crank angle code, and then start and run like crap. I could be wrong here, and it could change from year to year.

On page 264 of the EC.pdf file of the 2004 G35 coupe manual it says:

"When the crankshaft position sensor (POS) system becomes inoperative, the camshaft position sensor (PHASE) provides various controls of engine parts instead, utilizing timing of cylinder identification signals."

I haven't tried unplugging the UTEC, I just got back from zdayz and I don't really feel like ripping the car back apart for this. Also, I just installed the new UTEC and they both are reading the RPM the same way. I think an interesting test would be to get a hold of a digital storage o'scope and record the crank angle signal while the car is idling, then calcuate RPM from the actual sensor signal. This would, 100%, verify where the problem lies.

I would guess that the OEM ECU filters the crank angle signal coming in, and that is why it isn't a shielded wire from the factory. The ECU probably limits the maximum change per reading, thus eliminating the spikes and smoothing the graph.

 

The car will not run with the crank angle sensor unpluged..At least mine which is an 03 would not start.
There was also recalls on certain cars where the Crank position sensor would fail and the car would simply "shut off" on the road...
They may have made changes from year to year for safety reasons.

 

Kev,
Also I saw that you run KN technologies, and make several products such as RPM shift light and Traction control memory..Just cusrious if you have these products installed in your personal car, and if you think they may be interfering with the RPM signal coming from the crank sensor to the ECU?
http://www.kptechnologies.com/

 

I don't currently have a shift light in my car. I have already thought of that, and removed it. It was hooked to a fuel injector. I removed it when I had the hesitation problem, just to make sure there wasn't any interference. The module utilizes an extremley low current (high impedence) input and shouldn't interfere in any way, but I wanted to eliminate as many variables as possible.