Hondata

Hey Guys,

I don't really know much about Hondata yet as I'm just starting to learn...

Car: 1993 Honda Civic DX with TSX engine, EP3 Civic tranny
ECU: RSX Type-S
Calibration: k24-tsx-stock.kal (I may have changed a few things, what I have uploaded is attached in this post)


If anyone can take a look at it and see if anything is going wrong? The hesitation/bogging seems to happen at relatively higher rpms. At first I had a bit of a fuel leak so I thought that was the issue. I've fixed that and still seeing this issue. It's almost as if the car chokes during acceleration..but doens't happen all the time. Definitely happens a lot more when driving more aggressive (more WOT).

A little side note about my engine grounding (since I also was wondering if this might be the cause of it), I have the engine harness ground on the valve cover stud, however, it's on top of the thick washer that goes onto the valve cover, is that correct? Since it has a tab that sticks up, I figured that's the only way it would fit. For engine grounds, I put one on the intake manifold, one on the valve cover, and one on the tranny.

File attached...

You're running close to 14.6:1 AF at full throttle - once the ECU switches to open loop, you should be 12.5 - 13.2:1 (dyno tuning will tell you). The ground as you described it is in the correct location.

So the bogging now can be from too much fuel? I'm hoping it's all to do with a/f ratio and fuel pressure. After fixing the leak, my fuel pressure is now at 52psi (FSM states that is should be between 47-52).

The part that concerned me while looking at the data log is that at closed throttle, i see the a/f go up to 32:1!!! That's at almost closed throttle/partial throttle but is that normal? The INJ are at 0 during this time as well.

It is normal for the AF to go very high when the throttle is released, as there is air but no fuel.

14.6 at full throttle is too lean. It needs more fuel. We recommend that you take the car to someone who has experience dyno tuning with the KPro.

Sorry to bring a dead post back...been to two different tuners now and they are unable to get rid of the hesitation.

Joe (aka Jpax) may have talked to you guys already about this. We've spent two street tune sessions together (previously I have also had this tuned on a dyno at Carb Connections who are Hondata certified).

The problems that they are noticing is that although redline is set to 7100, we seem to hit redline around 6800 (almost seems to happen because of the bogging though).

I may have to grab the datalogs from Joe if he hasn't sent them already but from what I remember, the bogging showed the duty way out of the norm (I believe over 80+). Joe was wondering if I'm maxing out my injectors...

Being that I have a completely stock engine with stock injectors (engine is almost brand new) we thought maybe my grounding isn't sufficient. I redid my grounding with 4 ga battery cables...one from valve cover to chassi, tranny to chassi, and IM to chassi. Also the engine harness is grounded to the valve cover.

Any other suggestions as to what can cause this? If you need the datalogs attached, I will ask for them from Joe and attach them here.

On a side note, my fuel setup is as follows:
255 walboro pump -> fuel filter -> AEM FPR (set to 52psi) -> Fuel Rail
From the FPR, I also have a fuel return line.
I have attached a drawing of my fuel setup...

The TSX stock fuel rail only has one inlet. I believe most 92-00 civics with RSX swaps run the FPR after the fuel rail. Could my fuel setup have any issues?

The pertinent question would be: what is the fuel pressure, as measured on the fuel rail, under full load/high rpm? Followed by: what is the AF as measured by the dyno's wideband?

It could be that the fuel pressure is dropping under load, or that the problem is now fixed and the injector duration is too high for the fuel pressure, but the above two items would be a good starting point.

For the first questions, I guess I will not be able to find out unless we are on a dyno...I am hoping to schedule another session so we can not only tune with wide band but also be able to monitor the fuel pressure at WOT and high rpms.

Being that the a/f ratio (from datalog) doens't gradually lean out at high rpms, I didn't think that would indicate loss of fuel pressure. I just get a instant lean mixture just during the split second the car bogs and duty cycle goes way up.

I will record a datalog during my lunch break and attach it here along with my calibration if that helps in the meantime.

BTW, I DID change my fuel setup to how it is recommended...getting a GE fuel rail and placing the FPR after the fuel rail rather than between the pump and fuel rail as I had it previously...

What is your battery voltage when the problem occurs?

Looks like it drops to 12.70V? Not sure if that is bad or not.
At idle, the FPR is set to 52psi fuel pressure.

I have attached my calibration I am currently using as well as the data log when the bog occured. It just happened once for a quick split second and I believe you can see it at cursor position 03.731s.

I noticed it's VERY hard to catch this while dataloging. When the bog does happen, it seems to disconnect so it doesn't get recorded. The only time it continuously record up to redline is when the bog does NOT occur. :?

Anyway, hope you can help!

Forgot to mention fuel pressure was set at 52psi but raised it to 60psi to see if the problem would go away. Still exact same problem...Not sure if that proves it's not a lack of fuel though? (Since I have no way of monitoring fuel pressure while driving since my gauge is in the engine bay...)

This sounds like some kind of wiring problem, possibly a ground issue. You may also have a charging problem if the battery voltage is dropping below 13.25 volts.

Hmm...ok, I would first suspect my battery then? I'm pretty confident I've got good grounding as that was my original problem. I now have 3 battery cables for grounding in the following locations:
Valve cover to Body (sanded down all body contact points so it's metal to metal contact)
Transmission to Body
Intake Manifold to Body
Engine harness injector ground to valve cover

ECU is mounted on stock location so I assumed this would be a good ground by the bolts securing it to the chassi?

Do you recommend I get my battery tested?

Sounds like the ground next to the passenger side engine mount has been left off.

something is wrong with my battery voltage readout also.

but the trippy part is this.

hondata kmanger software reads my voltages wrong.

when I measure with my Fluke 73 III at the Battery it reads 14+ volts all the time, meanwhile in kmanger the battery voltage is going up and down...

I don't know why.. but I have changed alternators that didn't fix the problem.
So its either a bug on kpro software or something else..