Sputtering at speed, can't figure it out.

K-Series Programmable ECU installation questions / support issues
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AngryScottish
Posts: 25
Joined: Mon Dec 07, 2015 10:53 am

Sputtering at speed, can't figure it out.

Post by AngryScottish »

- what vehicle you have
Non-Honda chassis

- serial number of your K-Pro
41478

- version of software being used (from Help, About)
4.3.4; ECU is a KproV4

- the calibration (as an attachment)
below

- a datalog of a problem (as an attachment)
below

- anything about the car which has been modified from stock which may affect the ECU (don't include what sort of rims you have nor stereo etc).
K24A2 with K20 harness, turbo, E85, DW1300 injectors. PLX Wideband wired into Analog 0 and I have the parameters set to read off that.

- a specific description of the problem:
Car idles fine after it's warmed up. Drive it around and at around 3000-5000rpms, it sputters. AF (PLX Wideband) shows jumps around between 10.00-12.20, Ignition drops from 47' to 23', engine is bucking, knock threshold goes crazy, etc.

This happened 3 months ago, and I replaced the injectors, everything went back to normal. I replaced the injectors again... no change.
I've re-read the TPS signal (I have the throttle open a little for idle -- no iavc so "closed" reads 4%). No change.

I've tested the ecu in a RSX, no issue.

The car was running fine for two days, then this weekend, started sputtering and got progressively worse.
I have new coils on order, but not sure if that's the issue. Would hate to just keep throwing parts at it trying to figure it out.

Any ideas? Is it the calibration? Or something else?
Attachments
sputter.kdl
sputter starts 5.5s in.
(384.98 KiB) Downloaded 52 times
01272018.kal
(176.88 KiB) Downloaded 65 times

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Spunkster
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Re: Sputtering at speed, can't figure it out.

Post by Spunkster »

If the ECU works ok in another vehicle then you have either a mechanical issue or a wiring issue. You will have to use process of elimination to determine where the issue resides.

AngryScottish
Posts: 25
Joined: Mon Dec 07, 2015 10:53 am

Re: Sputtering at speed, can't figure it out.

Post by AngryScottish »

Spunkster wrote:
Mon Jan 29, 2018 12:26 pm
If the ECU works ok in another vehicle then you have either a mechanical issue or a wiring issue. You will have to use process of elimination to determine where the issue resides.
Is there a possibility of it being tuning related? Perhaps knock ?

I'd imagine a wiring issue would have been evident right away and not take a few days to show it's face.

Mechanical, possible...

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Spunkster
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Re: Sputtering at speed, can't figure it out.

Post by Spunkster »

Has this been properly tuned on the dyno?

AngryScottish
Posts: 25
Joined: Mon Dec 07, 2015 10:53 am

Re: Sputtering at speed, can't figure it out.

Post by AngryScottish »

For those who run into this issue in the future... while I haven't completely solved it, I have isolated it somewhat.

I have an Acuity TPS, no IAVC. So, I have the throttle stop threaded out slightly so the car will idle.
My TPS readings were 4% at fully closed. 98% at fully open.
I readjusted the TPS so that at fully closed, it would read 0%... or as close as I could with the 15s I spent on it -- getting it to 0.5%.

The RPMs at where I would get the sputter, moved. Also, before, I couldn't accelerate thru the sputter, now if I give it more throttle, it cleans up.

Not sure if this is the sole issue, but it's something I'll be working thru this weekend to solve.



Ah the joys of modified cars :D

AngryScottish
Posts: 25
Joined: Mon Dec 07, 2015 10:53 am

Re: Sputtering at speed, can't figure it out.

Post by AngryScottish »

More followup,

I re-calibrated the TPS sensor. Sputtering goes away, but will come back after some time.

Ordered another TPS to see if that fixes it.

Fun.

AngryScottish
Posts: 25
Joined: Mon Dec 07, 2015 10:53 am

Re: Sputtering at speed, can't figure it out.

Post by AngryScottish »

After a frustrating few weeks, finally got the engine to run right.

All because of a partially failing MAP sensor that never threw a code or any indication of it being the issue.


for those who come across this: try swapping the map sensor.

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