Hesitation on the highway

RedTeg95 · Post by **RedTeg95** » Sun Jun 29, 2003 9:02 pm

My setup:

I have a 95 Integra B18C1 (P72 ECU) with a greddy turbo running at 7psi (with intercooler) with 550 injectors. I have Honda stage 2b (datalogging). I have an after market fuel pump (255 lph) along with after market fuel rail, filter and regulator and the stock ignition system.

The Problem:

It all started shortly after adding the turbo to the car. I can't really put my finger on any one thing because I upgraded several items on the car at the time the turbo was added. Basically what happens is when I'm on the highway simply cruising between 60 and 80 mph (3000 to 4000 rpm), every once in a while the car will jerk like the engine was miss firing. This also sometimes happens during part throttle acceleration, but not a frequent. Other than this problem, the car runs great. At full throttle under boost the car is fine. One thing I have noticed while logging is that when this jerk happens, the O2 sensor goes lean for a fraction of a second. Also I should also point out that when it does happen I am not under boost.

What I have done:

I've been troubleshooting this for a while now. I've gone through the whole ignition system, replacing plugs (cold ones, normal ones), wires, you name it and have not come up with anything. So recently I've turned to the fuel system. For a while I was running 310 injectors that came with my turbo kit but I recently upgraded to 550s but that did not solve the problem. So next I turned to the fuel regulator. I had a B&M one but I moved the AEM model and I also upgraded my fuel pressure gauge (just to be sure). Still, no luck. I should mention that after each of these upgrades I road tuned the car with a wideband (Stage 4, my buddy has all the programming stuff). Even during the tuning session the car would jerk every once in a while on the freeway but there was really nothing in hondata that was a smoking gun other than the fuel going lean for a split second (Again, it real
ly only happens when I'm on the freeway and I press on the gas a little bit). Also, closed loop or open loop it still has the problem.

Solutions?

Well, I almost out of them. It's really a shame because again the car runs great otherwise. This has just been a naging problem I would like to get rid of. Any help would be appreciated.

Thanks

QUICKSILVER RACING · Post by **QUICKSILVER RACING** » Sun Jun 29, 2003 11:13 pm

What have you done to tune your part throttle maps?

95gsrturbo · Post by **95gsrturbo** » Mon Jun 30, 2003 12:27 am

this is a problem i am having as well and have turned to Team-integra.net for a solution ( link to thread posted below) as well as honda-tech.com

It seems that many ppl are running into this with the p72 ECU and hondata, if you can, take a look and see exactly at what vaccuum its happening, many ppl find it in the area of 10 in mmHG and 5in mmHG

no where else really, some say its the EVAP and i am still looking into that and learning how to get around it, hondata told me its a problem with the tuner... so i switched tuners- same problem not solved yet....

if hondata has a solution please let us know
your description is perfect and i have the EXACT same setup, greddy kit on 550cc injectors, i have some built internals such as pistons and rods thats it. running only 9 psi but this prob happens in vaccuum so no difference-- you described the problem perfectly

QUICKSILVER RACING · Post by **QUICKSILVER RACING** » Mon Jun 30, 2003 2:13 am

Let me rephrase my question for those withh hesitation problems.

What is the a/f ratio of your car when hesitating.

I silved that problem and was due to a rich mixture at part throttle.

RedTeg95 · Post by **RedTeg95** » Mon Jun 30, 2003 12:21 pm

When we were doing the part throttle tuning, I recall the mixture in the problem area being within 1 to 2 percent of stonch (I was doing the driving, not the tuning). I will hook it all up again and pay closer attention in that area to be sure.

Thanks

RedTeg95 · Post by **RedTeg95** » Mon Jun 30, 2003 12:26 pm

Oh yea, one more thing I have also noticed as well that this missfire happens in the area of 10 in mmHG and 5 in mmHG of vaccuum.

Crazy stuff.

I'll keep hacking away.

Thanks

turbosi92 · Post by **turbosi92** » Mon Jun 30, 2003 12:27 pm

95gsrturbo wrote:this is a problem i am having as well and have turned to Team-integra.net for a solution ( link to thread posted below) as well as honda-tech.com

It seems that many ppl are running into this with the p72 ECU and hondata, if you can, take a look and see exactly at what vaccuum its happening, many ppl find it in the area of 10 in mmHG and 5in mmHG

no where else really, some say its the EVAP and i am still looking into that and learning how to get around it, hondata told me its a problem with the tuner... so i switched tuners- same problem not solved yet....

if hondata has a solution please let us know
your description is perfect and i have the EXACT same setup, greddy kit on 550cc injectors, i have some built internals such as pistons and rods thats it. running only 9 psi but this prob happens in vaccuum so no difference-- you described the problem perfectly

OK, if you can post a link to posts you are talking about in H-T and TI.net.

I am having the exact same problem. The only difference with me is it is with a P28 and on a turbo D16 motor. Any help would be appreciated. I am also running 800cc injectors (for when the motor gets here.)

QUICKSILVER RACING · Post by **QUICKSILVER RACING** » Mon Jun 30, 2003 6:22 pm

Possible causes....

1. CAMs if it is not stock.
2. VTEC POINT
3. IAB opening RPM
4. Fuel too rich
5 FUel too lean

I really think it is more of a tuning issue. It would be great of you send your datalogs.

RedTeg95 · Post by **RedTeg95** » Mon Jun 30, 2003 7:48 pm

The cams are stock (GSR) and the vtec point is set at 5200 (which is beyond the range I see the problem). Cam gears are tuned +2 on the exhaust and -1 on the intake (or was it the other way around, I always get that confused) to remove some of the overlap. That was done at the dyno but this problem was happening before that. I was hoping the dyno tuning would help, but no luck. As for the IAB and the fuel, I will do more investigating. I'm in the process of putting some logs together. I will post some tomorrow night.

Thanks for the help.

Mike

hybridsol · Post by **hybridsol** » Mon Jun 30, 2003 8:02 pm

QUICKSILVER RACING wrote:Possible causes....

1. CAMs if it is not stock.
2. VTEC POINT
3. IAB opening RPM
4. Fuel too rich
5 FUel too lean

I really think it is more of a tuning issue. It would be great of you send your datalogs.

OK, I was the one tuning the car... this problem is very strange. It seems like the tip in adjustment is not working properly... but to answer your questions:

1. Cams are stock
2. VTEC point was set at the dyno (note this problem occurs under vacuum at part throttle) to 5200
3. The IAB doesn't exist- he's got a skunk 2 intake
4 & 5. The widband (DIY Techedge) showed 15.0 to 14.2 in this range, pretty good for a road tune.

It's really wierd, the wideband didn't pick up the blip in A/F, because it's so quick, but the stock sensor has such a fast response time, it does.

It only happens on part throttle tip in under vacuum. I tried disabling the knock sensor, and we ran in open loop too- no difference.

If we went from 5% throttle to like 7% throttle it would happen, but mashing the pedal did not always produce the "bump".

It is very apaparent ther is something wrong with some setting. We did NOT try to play with the throttle tip in adjustment setting, yet.

I have 440cc injectors with a P28, and have not had this problem.

RedTeg95 · Post by **RedTeg95** » Tue Jul 01, 2003 8:50 pm

Here are some of the logs. You will see that in some of the cases when the TPS increases some the O2 goes lean for a split second. That is when the hesistation is happening.

http://mywebpages.comcast.net/mwilde22/hondata/

QUICKSILVER RACING · Post by **QUICKSILVER RACING** » Tue Jul 01, 2003 9:20 pm

YOu car is running extremely rich at 8:1-10:1.

Your hesitation problem is caused by reason number 4.

You are reading the wrong A/F log.

There is a graph named Lambda in the Hondalogger. To understand what I mean Use the datalogging option in the Romeditor and press SHIFT+F3. You will see the actual lambda reading.

RedTeg95 · Post by **RedTeg95** » Thu Jul 03, 2003 1:03 pm

The Lambda conversion table in the Hondalogger is set so 1.00v = .80 so that indicates it is not running rich. Right? If not I guess I need a little more clarification.

QUICKSILVER RACING · Post by **QUICKSILVER RACING** » Thu Jul 03, 2003 6:21 pm

The conversion table in the settings menu is O2 voltage and A/F range.

But if you put 1V = 0.80 lambda = 11:1 A/F ratio. Still very rich IMO.

I think you should use FJO or MOTEC. I haven't seen data for techedge so I can't speak for the interface problems your facing.

95gsrturbo · Post by **95gsrturbo** » Sat Jul 05, 2003 10:38 pm

sorry for the delay in response -- but it seems that my answers are the same as all the above--- stock cams, untuned, I am running a 12.0 A/F across the board until top end where its richend up a bit in the event of a boost spike. (11.5 i think) but still the prob is in Vaccuum.

I am running stock IM and was told the EVAP may be a problem-- what is that and why?
TI link below

http://www.team-integra.net/forum/displ ... age=Search