PMAS Request

[03terminat0r]

Would anyone with a PMAS cai mind posting some pictures of the clearance between the intake and the engine coil cover.

I have been trying to resolve some false knock issues and I believe my jlt cai 123mm could be causing it. The intake tube sits very close/on the coil cover and I'm wondering how the PMAS intake tube fits. Someone with the same issues resolved their false knock by switching from a jlt cai to a PMAS cai.

I have checked everything else and cannot fix the issue.
Mods on the car: jlt cai 123mm, 2.4 upper pulley, metco 90mm idler, mrt o/r h pipe, borla atak, upr lca, upr uca, upr panhard bar, eibach pro springs, jpc line lock, strange front struts, stainless steel clutch line, viking shocks, wot box, shawn foster sound tube, mgw II shifter, 3.73 gears.

 

[StrayBullitt]

There's No chance in heck your plastic intake tube rubbing on the valve cover is triggering your knock sensors. You are probably having Actual knock. And if anything with the JLT intake tube, it would be the sensor mounting flange allowing a leak and incorrect maf sensor readings, which would affect fueling/timing and potentially lead to actual knock.

 

[03terminat0r]

There's No chance in heck your plastic intake tube rubbing on the valve cover is triggering your knock sensors. You are probably having Actual knock. And if anything with the JLT intake tube, it would be the sensor mounting flange allowing a leak and incorrect maf sensor readings, which would affect fueling/timing and potentially lead to actual knock.

I've been data logging through Lund's tuning support for about a month now and they assured me it is false knock. I switched to higher quality fuel (108 octane) to deal with any possible poor fuel issues and there was still knock. I was sent a new tune with lower timing (closer to stock I believe) and the data logs still show knock retard.

 

[StrayBullitt]

Interesting, did they see anything in the MAF signal that would indicate an issue there?. Possibly you have a maf sensor issue, you might even consider re-torqueing the knock sensors or replacing them. I just don't think you can re-create the type of frequency they are designed to pick up on with plastic and it would be such a low impact even if it were contacting the cover. Do you have any fretting on the bottom of your intake tube to indicate it actually is coming in contact ?

 

[me32]

Have you tried putting the stock intake on and having a revised tune? I'd start there.

 

[03terminat0r]

Interesting, did they see anything in the MAF signal that would indicate an issue there?. Possibly you have a maf sensor issue, you might even consider re-torqueing the knock sensors or replacing them. I just don't think you can re-create the type of frequency they are designed to pick up on with plastic and it would be such a low impact even if it were contacting the cover. Do you have any fretting on the bottom of your intake tube to indicate it actually is coming in contact ?

They have not said anything about the maf, but since you have brought it up I'm starting to think it could be the problem. The intake tube did have some cutting into the underside of it from the coil cover, but as you said that contact shouldn't set off the sensors. ( I was just going over literally anything as I have been dealing with this for a while)

I'm going to look into the maf situation and go from there, because everything else is tight and bolted down on the car.

 

[03terminat0r]

Have you tried putting the stock intake on and having a revised tune? I'd start there.

I'll put the stock intake back in and load a previous tune to see if that changes anything

 

[me32]

I'll put the stock intake back in and load a previous tune to see if that changes anything

I would check that 1st. Because something isnt right. I'm gonna guess that it's either tune related or something with the CAI intake causing it.

 

[paluka21]

Would anyone with a PMAS cai mind posting some pictures of the clearance between the intake and the engine coil cover.

I have been trying to resolve some false knock issues and I believe my jlt cai 123mm could be causing it. The intake tube sits very close/on the coil cover and I'm wondering how the PMAS intake tube fits. Someone with the same issues resolved their false knock by switching from a jlt cai to a PMAS cai.

I have checked everything else and cannot fix the issue.
Mods on the car: jlt cai 123mm, 2.4 upper pulley, metco 90mm idler, mrt o/r h pipe, borla atak, upr lca, upr uca, upr panhard bar, eibach pro springs, jpc line lock, strange front struts, stainless steel clutch line, viking shocks, wot box, shawn foster sound tube, mgw II shifter, 3.73 gears.

I have a similar situation with a PMAS 120 and Lund tune. Only other modifications my car has are 3.73's and an axle back exhaust. I'm seeing up to 1 degree of knock retard in 3rd and 4th gears, then quickly spikes to -1.0 - 1.5.
I'm considering pulling the PMAS and loading the stock tune back in to see if the problem still exists, because there is no way my car with a tune and CAI only should have positive knock.

 

[RBB]

I have a similar situation with a PMAS 120 and Lund tune. Only other modifications my car has are 3.73's and an axle back exhaust. I'm seeing up to 1 degree of knock retard in 3rd and 4th gears, then quickly spikes to -1.0 - 1.5.
I'm considering pulling the PMAS and loading the stock tune back in to see if the problem still exists, because there is no way my car with a tune and CAI only should have positive knock.

How much timing is in your tune? I just got done tuning a 5.8 with Lund last week and he was initially running what I considered to be way too much timing for the boost level and load on 93 octane. The knock sensor was pulling 6 degrees on the initial runs and 3.5 after a full bottle of Octanium! His initial response was to turn the knock sensor off because he thought it was false knock, until I insisted we try some octane booster first. I don't know what it is with some of these tuners....I've seen a lot of issues with knock on these forums over the years and it's always blamed on false knock or bad gas. 9 times out of 10, I think it's simply the tune.

Also, keep in mind that it's not unusual to see a little bit of positive knock on initial tip in. If you're seeing very brief positive knock of up to 1* when going WOT which quickly goes negative, then I wouldn't worry about it.

 

[paluka21]

How much timing is in your tune? I just got done tuning a 5.8 with Lund last week and he was initially running what I considered to be way too much timing for the boost level and load on 93 octane. The knock sensor was pulling 6 degrees on the initial runs and 3.5 after a full bottle of Octanium! His initial response was to turn the knock sensor off because he thought it was false knock, until I insisted we try some octane booster first. I don't know what it is with some of these tuners....I've seen a lot of issues with knock on these forums over the years and it's always blamed on false knock or bad gas. 9 times out of 10, I think it's simply the tune.

Also, keep in mind that it's not unusual to see a little bit of positive knock on initial tip in. If you're seeing very brief positive knock of up to 1* when going WOT which quickly goes negative, then I wouldn't worry about it.

That's actually what I'm seeing. I'm getting ready to add some Boostane to my next fill up to see if it goes away. If it does, then I'm guessing there's too much timing in the car. If it doesn't, then it's probably false knock.

 

[JPs2013GT500]

You could also pull a few degrees of timing from the tune via the SCT device settings as a test.