After I installed my hondata my car has a studder right at -12 vacume. Has anyone else had this problem? It runs great other than that. Also does anyone know what hondata sets there boost cut at? Around 8 psi my car will cut off and when I hit low boost it will get fuel again.

 

Does the studder go away when your car warms up, or is it allways present at -12 vaccum. My car studders as well when I leave it at partial throttle, not accelerating. It only does it for about 2-3 minutes, then it goes away.

 

It does it whenever I hit -12 it doesn't matter if its floored or part throttle. Just a slight studder but it gets annoying.

 

mine does that too, I dont know what vacuum reading it is, but when I'm cruising around 75-85 mph (3000-3500 rpm) the motor will studder. It's like it doesnt have enough fuel for a split second and then will catch itself. It is annoying.

 

What causes this problem running rich or lean? Is anyone else having this problem?

 

I get studder from 3000-3500rpm at -350mmHg. I think it's the ignition timing though... because there is a sharp line in the map at that point (stock hondata ignition maps though... hmm) I tried messing with the fueling in that location and I was unable to get rid of it.

While cruising in this rev range I can just manipulate the throttle to get it to cross that load boundary, and the motor ALWAYS hiccups....

Dustin

 

same here, I have to let off the gas pedal just a tiny bit and then reaccelerate 2-3 mph to make it stop doing that. Really annoying when on the Interstate...

 

my car did the same when i had a hondata ecu.. when i changed to a powerfc the problem was gone.. this could be tuning or the ecu i really dont know for sure

 

Perhaps Doug can comment.

 

Doug sent me a chip that was supposed to fix it...it is a chip in your interface box. Too bad it didn't do anything for me. I am hoping when I get my car tuned, it can be taken care of.

Oh, and it sure does feel like leaning out to me. My hx was made to lean out alot, and it felt kinda similar, except it wasn't so violent when kicking back in.


[Modified by HXMan, 9:14 PM 4/8/2002]

 

Dustin,
Mine does the exact same thing! I can't figure it out. Perhaps it is the timing at that point. Occurs at highway cruising for me at about 75-80MPH (3800-4000rpm).

I wish someone would find an answer to this.

torin

 

Mine stutters down low (rpm's). if i am in a taller gear and low on the rpm 1500-2000 and i tip in my car misses. tried to tune it out with tip in/start fueling but to no avail. mine does just fine on the freeway. I am not yet boosted so maybe that has something to do with it. i will know next week.

 

that sux. keep us updated once you find a solution to the problem. this might affect alot of Hondata users in the future.

 

my car stutters as well. i was told that it is due to the large injectors i have (720cc) and i had a new chip burnt for me by the tuner but it still does it every so often but, it isn't as bad as it was before where the car would jerk a lot.

 

sounds like a bug in the programming...you should all report it to Hondata...
Find out if its isolated to a single model of ECU . If there is a bug (which it sounds like there is), try to see if they have a fix. Sorry for the 'Microsoft way' problem diagnosis (from years of being an IT engineer) but its what I'd do...



[Modified by MiraiZ, 10:34 PM 4/9/2002]

 

i experienced this too, the car would studder at interstate cruising speeds.. after i got it tuned, we took the car out on the hwy and the problem was still there.. so i took it back to the tuner and they made the ECU run in closed loop or open loop, dont know which one.. and now the problem is pretty much gone.. though i do feel it very slightly but not as often and as harsh as before..

solution: try to get the ecu to run in closed or open loop.. not sure which one but its one of the two...

 

My car only does it when warming up, or if warmed up and the car is turned off and then on again.

I think the ECU is attempting to go into open loop too soon. Maybe the O2 sensor isn't warmed up completly, and is giving the ECU the wrong or inconsistent signals. I should try disconnecting the O2 sensor completly. Lately I have just been driving around with a 96 P72 for the gas milage. The top end does seem great though, once I get through the bogging period.(I have a b16a2)


[Modified by HXMan, 11:34 AM 4/9/2002]

 

i had a P28 if that helps you guys out at all.. doug sent me a revised chip to go inside my interface box as well.. i dont know which revision though

mine would studder even after 30 minutes of freeway driving

 

To help us determine what is happening here, would those of you with datalogging capture this event and email doug@hondata.com the datalog along with a copy of the ROM you are using..

thanks,

Doug

 

I don't have datalogging, wish I did. Doug do u have any idea what this is or do you have any experiance with this problem?

 

Happens worse in closed loop but still exists in open loop. I find open loop to run much smoother.

 

refresh my mind on the difference of close loop and open loop since the dam SEARCH function is dead...

 

First of all, tuning the part throttle with a wide band for correct air fuel ratio is recommended.

Closed loop is where the O2 sensor adjusts the fuelling to 14.7:1 from the fuel values in the map.

Open loop is where there is no adjustment.

The problem as described seems to be a leaning of the mixture. We have not seen this in our own daily driver test vehicles (I put in 2 hours driving, datalogging and tuning today), which is why we need feedback from users in the form of datalogging.

Doug

 

Doug.. I inquired about this studder a while back and I sent several datalogs and a ROM. I will resend the stuff again tomorrow after I make a some runs tonight!

 

^^^

Figured I would move this up. I know dustin has datalogging and the problem......