5 X 7 Replacement dry air filter for JLT big air causing cruise surge

[Robot_trainer]

Anybody replace the standard oiled S and B 5 X 9 air filter that comes with the JLT big air kit with its replacement...5 X 7 dry filter? I did this with the JLT prefilter sock and now I'm seeing some slight surging at 2000rpm cruise speed. Idle, acceleration, power are fine. RPMs above 2000 are fine, it just that one area. More annoying than anything. probably wouldnt notice on an automatic. I installed the diffuser. No different. I re-install the old 5 X 9 and it goes away. Lund did the tune. I have a ticket in but havent heard anything yet. Probably real busy. Anyone else experience this? I just cleaned the MAF. I doubt it will do anything. Id run another 5 X 9 but I think they are discontinued so I have to fix this.

 

[OldYeller]

Did the original filter have the wire screen on the outlet? My 11 does the same thing. It seems to not like any of their filters other than the one that originally came with the JLT. I’ll be curious to see what you come up with.

 

[Robot_trainer]

Did the original filter have the wire screen on the outlet? My 11 does the same thing. It seems to not like any of their filters other than the one that originally came with the JLT. I’ll be curious to see what you come up with.

 

[Robot_trainer]

Yes, mine did. They said a tune tweek was needed. They did one form me. Either it was coincidence or bad luck, but Ive had problems ever since. I put the old filter back and the original Lund tune

 

[me32]

Why did you make another thread if you already had this thread going about the same issue?

Part of the issue you are having is caused by a dirty maf signal that is known with JLT intakes. Thats why JLT added the screen on there filters.

 

[Robot_trainer]

Why did you make another thread if you already had this thread going about the same issue?

Part of the issue you are having is caused by a dirty maf signal that is known with JLT intakes. Thats why JLT added the screen on there filters.

Im trying to figure out if the problems I am having are related to each other or coincidental. Trying to appeal to wider audience that may have an idea where this is coming from, because it's baffling me. It off to the dealer next to see if they can see anything not right with any of the sensors and why the idle wont settle when last week it was fine.

 

[railroad]

I put a crate Coyote in a kit car. I had the MAF sensor too close to the throttle body and it surged at all cruise speeds. Lund was doing the tuning and it ran great otherwise. The tuner told me about the sensor location. I extended the distance and it cleared up.
I sent a before and after picture to the tuner. The tuner told me to shield the air filter from wind or radiator fan blast as it might affect the idle quality. It did affect it, though not as severe as the surging.
A screen between the throttle body and MAF sensor might help.
Hope this helps.

 

[Imatk]

I'm a little confused, did it not go away after you put the original filter on with the original tune?

If it didn't, I would check for air leaks somewhere. If it's pulling air from somewhere else (around the filter housing, around the tube to the throttle body etc) you're going to get that surge.

Check your actual MAF sensor. Make sure it's nice and clean as well.

If you do all of that you should certainly be back to your "original" state that worked. Then maybe go from there if you want to swap the filter again.

 

[CobraBob]

You said the issue went away when you put the original 5X9 filter back in. So, why not clean the filter, re-oil it, and use it?

 

[biminiLX]

Do you have this foam restrictor in place on your JLT airbox?
I still think something else is happening with one filter causing it but not the other.
My tuner strongly believes in running this foam piece and helped JLT develop it for the GT500.
-J

 

[blue 07]

Clean your maf, and get rid of the foam blocker ! Similar issues on my 13 GT500 with the blocker, it restricts to much air with my ported elbow and blower, no issues now

 

[Robot_trainer]

I like to have some consumable spares on hand. So when I looked into ordering a replacement filter, I kept getting told how great the new design was and the old was disco'd. The new filter had the surge with or without the diffuser. Going back to the old filter solved the problem. Trouble was I was now stuck with a 100 dollar filter I couldnt use. As for the MAF, the original and a new replacement did the same thing. Long story short...I sold the JLT, put the OEM cold air back on and the old 91 octane tune. Its never run better. Trims are almost zero now in all conditions

 

[me32]

I like to have some consumable spares on hand. So when I looked into ordering a replacement filter, I kept getting told how great the new design was and the old was disco'd. The new filter had the surge with or without the diffuser. Going back to the old filter solved the problem. Trouble was I was now stuck with a 100 dollar filter I couldnt use. As for the MAF, the original and a new replacement did the same thing. Long story short...I sold the JLT, put the OEM cold air back on and the old 91 octane tune. Its never run better. Trims are almost zero now in all conditions

Glad to hear everything worked out well.