Hi all. Just bought a buddy’s wrecked 09zx14. It runs and drives just when rolling on throttle between 3500-4500 every gear it will stutter. Kinda like surging really fast. Smells really rich while it’s doing it and occasionally black smoke from exhaust. Has pc5 Brock’s full exhaust and k&n air filter. Other than that it runs fine hauls a** when you want it to. Anyone know?
So far I’ve completely removed powercommander still did it. Reinstalled it. Check coils. Primary resistance was 1.6 on all. Secondary was around 10.9 plugs were pretty carboned up. I pulled fuel pump out took out filter looked like plastic crap and some green looking tape in the filter and floating in tank. Tried to clean it but still pretty dirty and doing the same thing. I have another fuel filter ordered. Any other suggestions?

* Last updated by: littleZ14 on 9/24/2018 @ 9:38 AM *

I'll walk this out as I type in the think... things shrink when old and dried up sitting for years.

Yes, but wouldn't that spit out of the injector rail too? Is that the smell of gas?

But it only happens around said rpm range. Key on would spray out the rail but does not, right?

Okay, then how about a change of plugs and see how the plugs look at said rpm and did they carbon up or just one?

I want a hot running bike so when I pull the plugs I can more pinpoint a hot sparkstick signing off when hot. Cold value readings are different when hot.

Did you change the plugs while in there? I had a mis-fire at idle and low rpms that stopped around 5k rpms. The plugs looked perfect on all cylinders, I finally listened to Hub and changed them anyway and problem solved.

I don't think this is your problem but you haven't ruled out spark as an issue until you have changed them. Then you can dig into fuel problem symptoms. I have a fuel pump you can buy if you want to rule out yours. 50 bucks plus shipping is about half of ebay.

Good luck.
Chewy

* Last updated by: ExWifesChewToy on 9/24/2018 @ 10:41 AM *

Plugs.....change them

The guy I bought it from put a new set of plugs in 4 months ago because he thought that was the reasoning behind it doing the cutting out. When we pulled them out Saturday I cleaned them up and shoved em back in. The Tip over sensor is also destroyed the only thing left of it is the circuit board and the connector. Plastic housing is toast yet it just dangles under the makeshift headlight for now. Plugged in it runs and unplugged it doesn’t.

* Last updated by: littleZ14 on 9/24/2018 @ 12:23 PM *

This is going to be a check&look. Remove the tank. Remove the service doors on top of the frame. Make sure each port is dry. Ratchet the subthrottles open, it will cycle back to normal when key is on. WOT the throttle. All ports look dry, right? Reconnect the tank. Prop up the tank to view the intake ports. Turn the key on, kill on. Turn the key off. Remove the tank or say you can loophole removing the tank, just raise it high enough to R&R the service doors. Cock the tank off to the side if need be, but did the ports become wet?

I'm chasing injector/oring bleed under pressure.

I want new plugs. Why? I want to pull them with less than a mile on them. Why? I want to see if all or one plug is causing this problem. If it's all it's the ECU. Can't be the orings giving up all at once or are they? Can't be each injector that's stuck with the varnish, and no, it's fast when I want it. It's at a certain rpm or all ranges of rpm, then it's rich no matter WATT, it's not the ECU, but excess fuel from each injector sticking? Gas is a detergent, it should clean it up from sticking some or not?

Change the plugs or chase your tail. That's your xray reader.

While I’m putting in the new fuel filter sock tomorrow I will do the checking ports as well then. I have spark plugs ordered CR9EIA-9 iridiums. Will change them as well. Thanks hub, will report with what I find out.

here is a picture of a sparkplug after cleaning and riding for 2 or so miles yesterday. just putting this up.

Also I just took the filter out blew some air thru it. It wasn’t really dirty. Took the bike out and it ran fine cold. Didn’t stutter or nothing. About a minute of riding it started doing the stuttering.

* Last updated by: littleZ14 on 9/24/2018 @ 5:42 PM *

that plug looks like its from my grampa's old Buick and the carburetor choke is stuck open

that plug looks like its from my grampa's old Buick and the carburetor choke is stuck open

are they all like that?

Yes they are all like that.

When you removed the pc did you actually disconnect it or just put it to a zero map?

Chewy

I disconnected the two connectors one and plugged stock back in. Took around the block and still did it.

5 whys of trouble shooting

1. Why is it stuttering? Its fouling the plugs after a few miles
2. Why is it fouling the plugs?
a. Maybe its running rich. Why? (can you check/measure A/F ration with a wideband sniffer)
b. Maybe the injectors are fouled open. Why? ( can you get them flow tested)
c. .... Why? (

See the process? After the 5th Why is correctly answered you should found the root cause

Not trying to be a smartass, I just have broken a lot of things I designed in testing and I always have to figure out why and get to root cause in order to fix a complicated system

Way rich.Is the deposit wet or dry?Maybe try some injector cleaner...it's cheap and might help?You replaced the fuel?Air cleaner good,so that's not an issue.

MAYBE...long shot..the map in the PC IS a zero map.You can hook that PC up with a 9 volt jumper and the software(loaded into your computer) and see what map is in there.The ECU should be reading that PC map when connected.If it's running the same..something is wrong if that loaded map is something different.That would describe a faulty PC...right?OR a damaged ECU..could happen if it was in a wreck.

"So far I’ve completely removed powercommander still did it".So no change with that Brock's mapping in there.You SURE that PC was connected right?I mean,all the pins are okay,right?Your ecu isn't reading it.PROBLEM.

* Last updated by: Grn14 on 9/24/2018 @ 11:06 PM *

Deposit is dry. Fuel was fresh. All the pins are connected on the pc I’ve checked the ground on it it’s good. Get a power light when running and a status and power when hooked up to computer. A friend is the one who had hooked up his computer to the PC And loaded a Brock’s map. Then we put his autotuner on it and rode it came back and accepted the trims went out again and there wasn’t really any other trimming to be done in that rpm range

When you say the pc is out of the loop, was that just removing the ground wire from the pc? I don't think that is going to work. See, the injectors are grounded and that means the pc connectors there are still in the loop because the injector is grounded and resistance is still connected to the bike. That's why the tail is still being chased.

The fallacy is that you cannot clean a plug without the blaster blowing off the carbon all the way down the porcelain and hope it's not internally fouled. So just taking a steel brush over the nose and side electrode is not how one cleans a plug. See the tail chasing going on times 2?

The pc is back in the loop, no AFR sniffer to see where the saved tune is running at ratio wise? We ran it cold in the morning and saved the map. Now it's hot as hell and the fuel is so rich, it runs better in the morning. See the first scenario and now 3 is the charm chasing tail.

Signed,
NOLTT (no one listens to turtle)

Power commander was completely unplugged. Plugging stock harness back into stock TB connector. Going to put the new plugs and new fuel filter sock in and see what happens. If still there I will be taking it to get dyno’d to see what the AFR is and having it tuned. Will update what I find out.

When you took the PC out of the loop you were still running it on fouled plugs correct? When you get those fresh plugs installed; do yourself a favor and take that PC off once more to eliminate that variable.

Ray Charles can see that way too much fuel is being administered. Unfortunately the fuel management system has been hacked. For all we know the ECU has been edited.

I will be taking off the power commander once new plugs are in to rule it out completely. From what I can remember when the auto tuner was hooked up idle was around 13.2 AFR. Also I open the service ports opened up the secondary butterflys turned key on killswitch off they went down then came back open about 3/4 of the way then shut when key turned off. Did it with key on killswitch on same thing couldn’t really tell if it was wet in there or not.

Do know ANYONE...even a dealer that could switch that ECU just to see if it's okay?It won't harm the switched ECU to plug it in for a few moments and see what happens....just a thought.Book says DO NOT DROP or jar the ECU.Maybe????

Yes I will try and swap ecu with another guy I know around here. Should I try that after disconnecting powercommander and new plugs? Or wait untill after I try that.

If still there I will be taking it to get dyno’d to see what the AFR is and having it tuned.

I wouldn't take a bike to get tuned that isn't 100%. Dyno is only going to tell you that your bike is too rich....not why it is.

that PC off once more to eliminate that variable.

I would change the plugs.....leave the power commander off. If it runs fine, ride it a couple of hundred miles and then pull the plugs again.....no soot, put on your commander and go get dyno'd....soot, then keep looking for reasons, because the plug will likely foul again in time.

cleaning the screen is nice but won't rule out the internal fuel filter that you can't get at and you probably still have a dirty ass fuel tank unless you start with it first.....clean it with kerosene and then clean the screen. Then clean the injectors. I have a method for doing that that only takes 15 minutes to do and you don't have to remove the injectors. PM if interested.

I wouldn't let GOD borrow my ECU but your buddy may not have a problem with it.

Chewy

* Last updated by: ExWifesChewToy on 9/26/2018 @ 9:32 AM *