MAF O-ring & Pics!!! :D Lol ...

**TheYanz** · 02-09-2012

Hey anyone out there in GTP Land ever discover any issues with that elusive o-ring that sits around the MAF up top right where it drops into the hole on the throttle body? Yup there's definitely an o-ring there. The stock one on mine was black & not that thick. I recently bought a variety pack of those green fuel/ ac o-rings from Advance for $5. I believe there are 24 of them in there in multiples of 4 I think. I needed them for when I went to recently change my fuel filter. After swapping out the filters it kept leaking every single time I would look under to check for leaks after pressurizing the system. I kept thinking it was the quick connect clips not seating right but after talking to a mechanic friend of mine he suggested that the flexible end of the fuel line has an o-ring or 2 inside. Look there he said. Sure enough THAT was the issue. So I carefully pried off the black MAF skinny o-ring & tried 1 of those nice, fatter, green ones from the pack around the MAF. I recently home ported my L67 throttle body. See the pic links at the end for what I've been up to lately

So I've been kinda messin' with & inspecting the throttle body & sensors, wiring, etc. over the last couple days. After slipping it on & putting a tiny dab of Vaseline around it I noticed the MAF sat much more snug in the TB hole. & just earlier I checked for vacuum leaks with TB cleaner. No change in rpms after spraying around various TB spots. But it was on a somewhat colder engine. I took the car for a test spin & it was picking up & taking off like I've never seen it do before. Could something so stupid be the cause for my recent general sluggishness & drivibility problems? & I've checked & tried swapping out literally everything up top with spares from a engine swap in October. I have one of those Scan-Gauge brand things mounted behind the steering wheel. I bought it to monitor KR & all the other engine parameters a while back. It didn't come with the MAF PID programmed in but I was able to find PID info on Wiki & once u understand how all that works u can make it read out pretty much anything u want it to. However I've always been unsure of how to scale the data it reads back. But what I can say is that at idle the g/s displaying how I have it scaled used to read 20-25 & when I first started it up it read 40-50. After a warm-up at the end it came back down but no lower than maybe 30-35. & at the peak of a few good solid runs it climbed all the way up to 1100 or so with no hesitation. Haven't seen the MAF data read that high in QUITE some time. It was screaming down the road & the Boost hasn't felt that good for a long time. The air did seem very crisp & cold & there was a full moon out ;D What do u guys make of all this? The black o-ring allowed the MAF to just simply slide right in & out of that *****ng hole with ease. No snuggness. The fatter, green, lubed up one required a good push from the top to slide in then I was able to rotate it with minor persuausion then tested to see if it pulled out easily. Nope. It sat snug. Wtf? Never have I seen on GP Forums anyone ever mention anything about a MAF o-ring. Btw... I can't get enough of how cool porting the TB was. I love it. Check out the pics

**BillBoost37** · 02-09-2012

Y...

It would appear you ported your TB without changing the programming on the pcm. This can often cause your motor to run quite fast as you likely leaned things out. With things so lean, you may be heading for another motor swap.

**TheYanz** · 02-12-2012

Damn it! Thanks for the heads up. The LTFT numbers did go up a little. I have plans to get a custom tune REAL soon. Seems to be driving a lot better but I will be careful till that tune...

-Y-

**TheYanz** · 02-13-2012

Hey Bill I'm swapping back to the non ported TB for now. U were saying something about the motor or engine "running fast." Did u mean like similar to how the car runs when u introduce TB cleaner or some sort of flammable crap into the engine when checking for leaks & the rpms go up or like when u DEF have a vacuum leak & it idles at like 1.5K rpms noticeably quicker & u say "Oh, sh*t, wtf's going on?"

Because it wasn't doing that with the ported TB in. It idled VERY QUIETLY at 750 rpms. Yes the LTFTs did noticeably go up but are not in that +16 range. While cruising they'll sit at around +5 & at idle usually +8 to +10. I've heard +/- 5 is fine & optimal is as close to zero as possible. Guess I'll leave it out till that somewhat local tuner fellow can tune everything together safely. Again I greatly appreciate the heads up, bud. Thanks...

-Y-

**OH4CompG** · 02-13-2012

You probably just need to add a bit to the MAF table but it sounds like it's still pretty dialed in.

**BillBoost37** · 02-13-2012

Fast meaning..by more air entering than the maf calculations are set for...the engine will typically lean out more when throttling.. which makes it feel faster. The flip side is..you run more chances or predetonation.

On the 1500 rpm with the stock TB. I'd check it to ensure the throttle plate is closing fully and that the IAC is clean. It sounds like you now have a vacuum leak.

**coolone** · 02-13-2012

I noticed you've used Silicone tubing for some of your vacuum lines... the larger one might collapse after the engine gets hot, especially on top of the SC.

It's worth checking... and will definitely cause the sluggishness if it collapses during driving.

**SarasotaGTP** · 02-13-2012

so is there really supposed to be an oring on the maf into the tb?

**TheYanz** · 02-14-2012

Naw Bill when I said 1500 rpms I was using that as an example when I was asking is that wat u mean by the engine "running fast." I now understand wat ur saying by "MAF miscalculations" & that leading to a lean condition that seems faster but comes with some KR. Will a decent tuner person be able to adjust for that stuff? Is it just basically doing a normal custom tune or is there more that goes into that due to the ported TB? I put the stock TB back in & the car runs like complete sh*t. Think the stupid canned tune is seriously out of whack. Still waiting on that dude to custom tune this piece. With the stock TB in the LTFTs will drop to negative numbers often during cruise. I think to a max of -7. At times the LTFT will jump back to 0 or +1, +2, +3 but on the whole they'll sit low. Also with the stock TB when I accelerate from any speed it'll be sluggish as hell & the IGN timing will drop to numbers that IMO are not right like 10, 13, etc. Stuff under what I've been led to believe as acceptable numbers ie 15-17? With the ported one on a few street test sessions in the cold it ran as BlueGTP said once "a raped ape," Lol

Haven't seen it pull like that in a WHILE. Wat do u guys think? I know u'd rather be on the rich side than the lean side. But shouldn't the engine be fine as long as the LTFTS don't exceed +16 which it NEVER did w/ the ported TB? I mean up to +16 the PCM will be able to compensate & mix up the fueling to adjust, right? It's >+16 when it's out of range & the PCM can no longer adjust, right?

& yeah, there's an O-ring on the MAF. Sh*t at least mine. Whoops maybe I put one on there myself without remembering some time back

But think about it... It just kinda sits in that hole. The 2 other sensors on the TB have o-rings, no? Well at least the TPS does. Why shouldn't the MAF? All I know is that I now have one of those solid, fat green ones & it sits snug & doesn't just pull straight out when unbolted. I bet if u checked with TB cleaner or MAF cleaner (which is also highly flammable) u prolly won't notice the rpms increase hence no air leak but what the hell? I have one on & I LOVE IT! Lol Hahaha

Umm about the silicone crap... the vital vacuum hoses (MAP to LIM, LIM to FPR Split, other side of that to watever the hell that thing's called... forgot momentarily) they're all the small hard plastic ones with black silicone ones on the ends used only to ward off any possible leaks. The red ones are used for appearance only on that giant ass one for the vacuum brake booster line & also in 2 or 3 spots around the boost related stuff. All the rest of the red silicone is used instead of that stock crap for wire protection & effect. I know it looks like I have a ton of it but it's deceiving

Isn't the stock setup utilizing black silicone around the 2 boost parts? Also same thing on the vacuum brake line but that black stock stuff is DEF thicker that the red eBay silicone I got. I mean it does get softer & easier to work with on a hot engine. u may be right. It may indeed be causing issues.

Replay/ Post back guys. I like input...

-Y-

**TheYanz** · 02-14-2012

Hey Bill don't get mad at me. I wrote the later part of that 1st paragraph before going back & rereading ur comment. I get it... MAF table or watever is based on the rough volume of open space inside the stock TB. "MAF Miscalculations" def makes a lot of sense. So thinking ahead I'm assuming the tuner guy will need a new MAF table to start with given that I swap out the TBs before that long sought tune? i don't know sh*t about tuning but have read quite a few posts about it lookin' for other info in the past. Any have 1 of them HP Tuners for sale? & perhaps some advice? ;D

-Y-

**BillBoost37** · 02-14-2012

I'm not mad...it's sometimes tough to understand what you wrote.

Like this morning..the coffee hasn't kicked in and my eyes and brain simply can't quite understand much past "don't be mad". Sounds like something a girl might say to a guy after she's done something silly.

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