Popping/Gurgle on deceleration

[fr8dog]

A little background. 2016, black widow exhaust, flash from 2 wheel dyno.

Took to dealer for 78000 mile service. Check valves, replace plugs, air filter and throttle body synch. They also installed a clutch cable I had purchased a while back.

Before I took to dealer no popping or anything. On the ride home from picking it up it's kind of noisy. Not backfire out of carbs noisy but different than before. 

Called dealer when I got home. No call back. Ordered block off plates that I should have installed while waiting for the ecu to come back. 

Stopped by dealer yesterday. No clue. 

Will tear it down Wednesday or Thursday.

Maybe someone here has experienced something similar? Let me know, thanks!

Oh, bike runs great, like it was new. 

Dan

[skipperT]

Was a throttle body sync performed?

The black rubber caps on the intake manifolds can be torn fairly easily with whatever tool you need to use to get them off (pliers/hemostats) that’s one possibility that’s a bit sneaky. 
Since it sounds like the fresh air pump and hoses are still connected to the valve cover, make sure all that are secure. 
same for the breather hose, it can be viewed from the LH side, should  not be kinked. 
double check clamps to TB’s and to air box are tight and everything is set down where it’s supposed to be. 

that’s all I got offhand…

-Skip

[fr8dog]

Yeah tbs was done. I'll check all of that out. Something wasn't put back together right. Thanks

[Brentinpdx]

When I had my ECU flash done the tuner told me to block the hose that runs from the air box to the AIS and to disconnect the plug. Otherwise, it will be pop on decel.

[texscottyd]

@fr8dog - Was the ECU flash done previously, and you’ve already been riding it without the deceleration popping?   If so, I would think it has to be vacuum related (probably a reassembly issue) as @skipperT suggests.    

Let us know what you find.  Not that it’s a relevant compare, but my FJ (2WDW flash, stock exhaust, AIS block off plates) has zero deceleration popping noises.  

[OZVFR]

The AIS makes zero difference to performance whether its active or blocked.

I'm not sure if you already had the tune and wasn't popping, and now it is.

If it didn't before you have an air leak in the inlet system, I had the tune and left the AIS as is, I also don't mind the popping and farting even though it was greatly reduced after the tune.

 

[fr8dog]

On 8/4/2024 at 2:37 PM, texscottyd said:

@fr8dog - Was the ECU flash done previously, and you’ve already been riding it without the deceleration popping?   If so, I would think it has to be vacuum related (probably a reassembly issue) as @skipperT suggests.    

Let us know what you find.  Not that it’s a relevant compare, but my FJ (2WDW flash, stock exhaust, AIS block off plates) has zero deceleration popping noises.  

Flash from 2WDW. They also recommend AIS block off plates in addition to their flash. I didn't block off. Ran fine, no popping. 

I purchased the block off plates. Figured while I'm in there I may as well do it. Changed my air filter 10k miles ago. Should have done it then. Shoulda coulda woulda. Removing and installing the bodywork is a bummer.

I think @skipperTpointed me in the right direction. Everyone seems to think it's an air leak or vacuum issue. 

Tearing down later today. 

 

[fr8dog]

Thanks to all who chimed in!!

Popping is gone. The clamps on the throttle bodies weren't very tight. Not sure if that was the cause, but could have been. I didn't check to see if the rubber manifolds were on properly. I say that cause that was the hardest part for me. 

Installed block off plates. Now it runs like it did before the service. Instructions said to disconnect wiring from smog pump. No male connector going into it. I didn't even see one hanging around. Weird.

On a more serious note. I paid for TBS. It wasn't done. Caps had years of dirt on them. They hadn't been removed. 

Called service mgr. Said he would investigate. There are other issues with the service that I let him know about. I missed his call back. We'll talk tomorrow. 

I guess I need to learn how to check/adjust valves myself.

Thanks again, Dan

 

 

[piotrek]

On 8/7/2024 at 8:58 PM, fr8dog said:

Installed block off plates. Now it runs like it did before the service. Instructions said to disconnect wiring from smog pump. No male connector going into it. I didn't even see one hanging around. Weird.

...that would explain the popping. Moot point now that you have block-off plates on there... that connector is needed on the AIS solenoid to keep it closed. It's normally open, until power is applied. The flash keeps the coil energized (and the valve closed). The shop might have tucked the connector pigtail away somehow. 🤔

[skipperT]

On 8/7/2024 at 5:58 PM, fr8dog said:

Thanks to all who chimed in!!

Popping is gone. The clamps on the throttle bodies weren't very tight. Not sure if that was the cause, but could have been. I didn't check to see if the rubber manifolds were on properly. I say that cause that was the hardest part for me. 

Installed block off plates. Now it runs like it did before the service. Instructions said to disconnect wiring from smog pump. No male connector going into it. I didn't even see one hanging around. Weird.

On a more serious note. I paid for TBS. It wasn't done. Caps had years of dirt on them. They hadn't been removed. 

Called service mgr. Said he would investigate. There are other issues with the service that I let him know about. I missed his call back. We'll talk tomorrow. 

I guess I need to learn how to check/adjust valves myself.

Thanks again, Dan

 

 

Eesh. Sorry this happened to you.
 

Unfortunately there are techs out there who cut corners and don’t fully perform all the required/requested tasks on a RO. It’s good that the Service Manager attempted to connect with you and I hope that he does the right thing. This is their chance to retain you as a customer and protect/build their reputation and they should make it right. 

the bolts which snug up the clamps should only be “snug”, not overly tight  - otherwise they stick and will bend and twist the threaded ends of the clamp the next time it is loosened  due to the force required to break it free.

glad you solved the problem, and bummed that you had to do it yourself. 
-Skip

 

[fr8dog]

On 8/11/2024 at 9:24 AM, piotrek said:

...that would explain the popping. Moot point now that you have block-off plates on there... that connector is needed on the AIS solenoid to keep it closed. It's normally open, until power is applied. The flash keeps the coil energized (and the valve closed). The shop might have tucked the connector pigtail away somehow. 🤔

Thanks for the explanation!