Misfire at constant throttle

[Trex]

I'm having a problem with a constant misfire at around 1700-2800rpm.

Tried and Swapped;

Unplugging tps

Cas swap

Plug gap 0.6 - 0.8 - 1.0

Swapping coilpacks with others

fuel filter

fuel pump

injectors

 

I've attached a log file and a video.

 

I have zero idea where to go from here... This problem is only evident on idle and at constant throttle around the 1-5% throttle. 

4-11-2017_1915idlefluctuations.csv

Video.MOV

[Guilt-Toy]

put a fuel pressure gauge on the fuel line going into the rail and watch it when misses and look for any issues

[t_revz]

On 11/5/2017 at 11:54 AM, Trex said:

I'm having a problem with a constant misfire at around 1700-2800rpm.

 

I've attached a log file and a video.

 

I have zero idea where to go from here... This problem is only evident at constant throttle around the 1-5% throttle.

4-11-2017_1915idlefluctuations.csv

Video.MOV

Prob not the same thing but mine acted very similar when i built it from 1000-1500 and was a pain in the but to take off from stationary. 

 

turned out i had the intake cam 1 tooth advanced and when VCT  engaged it would hunt like yours and have no power. Disconnecting VCT or adjusting the TPS down a bit so VCT came in at a higher RPM kept it under control until i could pull it apart and adjust cam timing

[Trex]

 

On 11/5/2017 at 11:20 PM, Guilt-Toy said:

put a fuel pressure gauge on the fuel line going into the rail and watch it when misses and look for any issues

Thanks, I'm doing that this weekend. It has to be something related to fueling.

On 11/6/2017 at 4:10 PM, t_revz said:

Prob not the same thing but mine acted very similar when i built it from 1000-1500 and was a pain in the but to take off from stationary. 

 

turned out i had the intake cam 1 tooth advanced and when VCT  engaged it would hunt like yours and have no power. Disconnecting VCT or adjusting the TPS down a bit so VCT came in at a higher RPM kept it under control until i could pull it apart and adjust cam timing

I can't imagine it would skip a tooth, haha i hope not.

 

[Trex]

Haha I completely missed cell 67 - 72 - 113 - 172 - 220.

The tps is dropping out. Very prevalent today on the logs as it's getting worse over time. I tested so many things in the last week. I tested the voltage and throttle position percentage about 5 times each with nothing out of the ordinary, or more so that it was so quick, intermittent and sporadic that it never stood out.

The way we found out was watching the diagnostics window we could see the fuel cut go active and then noticed the tps was dropping out.

So i now need a new tps.

 

[Trex]

Thought I should post my findings.

Changed the TPS, it was just a coincidence mine was wearing at the same time.

It was my transient throttle turning on and off and not having the correct settings. It was injecting a lot of fuel and the o2 was trying to combat it. Causing an oscillation in the afr.

All fixed now.