I am getting some bucking while cruising. I was wondering if someone would not mind recording a log from 1st through 3rd in cruise mode (city). I would like to see RPM, and WIDEBAND data.
Thanks,
Chris

 

I am getting the same problem.. bucks/hesitates while cruising, but runs fine in closed loop?

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/hesitation-stumbling-lean-open-loop-injectors-637037/

i made a log, i will post tonight. im not sure if i have a log of when it worked right though. I think HAILERS is seeing the same thing, he posted the same problem on the teamfc3s forum

 

Ahh, so this could be a bug?

 

just got the car up and going, i done experience any bucking, but i only have 1 day on it... have a couple bugs to work out otherwise i would get you a log

 

3 of us with the 2.0 are seeing the same results. That is odd.

 

Ok, 2 logs i made driving to work:

(for the wideband log: 0v=9.8, 5v=19.8)

3_27_07-7_28_34_-_RX7L.PDB
I forgot to log TPS in this one, but the hesitation occurs at 3 seconds into the log. It drove perfect the rest of the log. You can see it go into closed loop several times, but during the hesitation, AFR is in the 18's. The AFR's get really high in other spots too, but i think that's decel fuel cut (boost is -20)

3_27_07-19_01_02_-_RX7L.PDB
I logged TPS this time, look for spots where the AFR is >15 and TPS >24. Hesitation occurs at 0:04, 0:41, 0:47, 0:54, and 1:00. I believe all teh other AFR spikes are decel fuel cut (TPS is 24)


in the spots where its hesitating, it looks like the injector d/c is increasing, yet AFR is increasing, which makes me think it was the injectors. I was about to pull my new RC 750's and put the stockers back in until i heard you are having teh same problem.. could it be the rtek??

 

You AFR's are way smoother than mine. The area I notice it the most is right around 2500 rpm 4.4 seconds, and 3000rpm 5.21-5.79 seconds into my log. Having trouble posting a log right now. Will try again later.

 

Here is a log of mine from yesterday. The AFR's where tuned up 10% under vacume. Still bucking like crazy.

 

Have you guys made sure your TPS setting is within factory specs? (not just unplugging it)

 

what % is factory specs? mine is 24% right now

 

Factory would be 20% +/- a couple (I don't recall off hand exactly) 24% is a little on the high side but shouldn't be causing what your seeing. Regarding logs:

gxl90rx7:
I see what your saying. Particularly at the 47s mark. AFRs go way lean. The odd thing is that you can see that the airflow and IPW do not diverge over this period (their ratios stay pretty constant), so it would seem that the ECU is seeing reasonable airflow, IPW is reasonable yet AFRs change dramatically. Since you have hesitation, its not air injection into the exhaust which leaves fuel starvation during that period as the most likely candidate. So:
- what kind of injectors do you have for primaries? Sounds like 750's?
- last time fuel filter was changed?
- what kind of WBO2 are you using
- what injector config are you using

Wankler:
- can you capture a log with airflow readings? I can see your IPWs changing with the WBO2 reading, I can't tell if the airflow is also changing during this period.
- what are you using for primaries?
- what injector config are you using

-Henrik

 

Henrik, thanks for taking a look. I have new 750cc high-imp (measured 12.5ohms) primaries from RC Engineering, bought and installed 2 months ago. I am using the 720/720 preset (with no corrections) and AEM UEGO wideband. I changed the fuel filter last week to troubleshoot. It seems the problem only happens in low-load situations, in open loop. No problems when cruising in 5th gear (higher load?), even when in open loop. havent really tried it in boost yet, for fear of ping

 

I have 550pri and 720 sec. Ohm's are fine on all 4. I as well have to FMIC, Hybrid T04, all emmisions removed. I will log on my way to work this morning.
Thanks,
Chris

 

Here is a log. I did notice this morning on my way in, my LM1 WB went on the fritz. I was not reading A/F, and the car was not bucking. I shut off the car, and it reset and started bucking. I am going to see if Innovative has a new software release.
Chris

 

Are you guys both using your wideband's simulated NarrowBand output for the ECU or do you still have the stock sensor connected to the ECU?

 

"wideband's simulated NarrowBand "

Yes I am. I also have spliced it into the APS input.

 

APS? You mean ATP? And I assume you have the wideband output spliced into the ATP, not the narrowband oputput?

 

i have the atp input enabled for the wb o2. I still have the stock o2 wired in like original. Altitude set for its lowest setting, since im on the coast

 

That is how mine is set as well Turbo. What WB you using gxl? Have you tried calibrating it? I am using the Innovative.

 

AEM uego, i havent tried calibrating it. you mean using the screw on the back?

 

i don't have a good log to show but i was experiencing the hesitation as well. about 2500 rpm part throttle acceleration. turned up my fuel pressure a bit and got rid of it. looks like i should double check the sidebands narrow band simulation to the ecu.

 

well today i tried the 550/720 preset, problems still there

 

I am pulling of my front bumper to check my IC piping. Hoping that is it. I am not so convinced it is the Rtek anymore. But time will tell.

 

I have the same issue as well, I had it with the 1.7 running a safc2 and I just assumed it had something to do with the safc. Maybe it's got to do with the fact that 2500rpm is where the ecu stops running closed loop under light throttle?(correct me if I'm wrong about the closed loop only operating under 2500rpm) I just installed the 2.0 the other day and I'm running the altitude set at 0 and using the atp for the aem uego, but i haven't tuned with it yet I just ran the 550/720 settings and left the safc2 set up. Haven't had time to tune yet. Anyway the bucking still exists, just like you guys said it happens at or around 2500rpm under cruise and my tps is set according to the fsm.

Brent

 

Maybe the stock o2 is on its way out?