The MAF likely needs to be recalibrated properly if you're getting a stumble. Chances are the VE hasn't been touched.

 

just a follow-up note on the stumble issue I have experienced. I believe it has been corrected. I have HP tuners software and the tuner guy told me to send him a log. He reviewed and said the fuel trims were fluctuating too much and that an air leak could be the issue.
I checked the intake manifold bolts and they were loose and not at the factory 89 inch pounds. I tightened them up and took it out for a drive. No stumble. I logged a file and the fuel trims were almost perfect. Drove the car for 100 miles and checked bolts and they were loose again and the stumble was back. Tighten then back to 89 in pounds and it runs fine again.

So I think I need to use some blue thread locker. I am ready to redo the bolts using the blue thread locker and wondered if anyone else has had to do this?

If you would like to review the log files and give me your thoughts that would be great. i can not upload them as they are not an accetable file format for the forum. I can email them to you. One is before the intake bolts were tightened and the other is right after they were tightened for the third time. When I say loose this is not a lot but they required about a ¼ to ½ turn to get to 89 inch pounds.

 

the stumble problem continues. It exists between 1,900 and 2,200 and only shows up when I accelerate slowly when in 5th or 6th year. it is more of an issue when the car has warmed up. My exhaust pipes indicate the car is running richer than it has in the past.

does this issue seem to be an indication of too much fuel ( rich ) and too much spark advance?

 

Thanks to the OP for the write up. It was nice having this thread to refer to as a guide making sure that I didn't miss anything. Surprisingly, my A6 heads/cam car ran well with no tune afterwards! I plan to do some WOT tuning and get some track times next week at Sac Raceway.

 

I'd get it tuned before I beat on it, particularly if you don't have a wide band and HP tuners to scan going down the track. My FAST leaned out my car quite a bit and also needed quite a bit less timing. I wouldn't have wanted to race as lean as it was with knock it was getting prior to tuning. The car ran well, but the WOT scans said otherwise (I have a wide band installed).

 

im a lil confused by the map sensor, on my stock intake it hat a T in it now you have it just plugged into the 102. what did u do with that other line that was ran.

did i do it wrong and should of got rid of the T

because after install im idling at 1k sitting and when im trying to drive it sits around 2k

 

^thats not right...

 

Dont mean to dig up a thread from the past. BUT, how did you guys tighten the last 2 bolts under the firewall. I am almost done with my install and ran into that issue!

 

You have to put those bolts in the intake before you slide it back, then hold them up while you align the intake. Clothes pins work well to hold them up.

Once the intake is seated I just used an 10mm (or is it 8) box wrench to tighten them. I never torqued mine....I have a pretty good feel for "Gutentight" on bolts from years of wrenching, and these aren't "I'll lose a wheel if I don't get proper torque" critical.

Edit - I see I answered the question, I think, in post 9 years ago!

 

These fastener requires "very" low torque. I am not a White Collar type.

After 39 years of nuclear Toolmaking with a touch of auto repair/maintenance that all my cars and motorcycles never see the inside of a repair shop - that was wrenching in excess. Experiences had taught me never to trust my own feel with any engineered torque requirement - especially with such a low torque. Torque requirements are there for a reason.

But do what you like!

 

The bolts I have are hex head 5mm, nifty huh? The 3/8 drive 5 mm hex I have is too fat to fit in there. Just ordered a 1/4 off amazon that should hopefully do the trick. BUT I have to wait another 3-5 days to have the damn car back together...

 

If I was working in the nuclear industry or even the airline industry on mission critical fasteners where people might die if fasteners come loose I'd use a torque wrench too.

This is the intake on your car. Worst case is you don't tighten enough and you have a vacuum leak. If you don't know when bolts are tight enough to prevent that you probably shouldn't be wrenching on your car. A 3/8 torque wrench won't fit under the cowl, and frankly, I've seen tons of examples of people screwing up ft lbs instead of inch lbs and breaking little bolts like this. So for a non moving part like the intake, I just tighten it to where my experience tells me is enough.

And like you say, I'll do what I like and you do what you like.

I should add that I've had my intake on since 2009, 4 years, and it's fine. No vacuum leaks from the bolts. I did have a vacuum leak when my plastic patch didn't pan out, so I've had my intake on and off several times in the beginning.

Matter of fact, I hot swapped an ported stock intake while my car was strapped to the dyno. I think it took me 12 minutes. So even though my job is white collar, my experience spinning wrenches in college has served me very well for 35 years.

I use a box end wrench. That fits.

 

Joe_G no justification is needed.

However, finesse does come in different levels!

Back in my past life when I first started out as an Machinist, it will take 4 solid years of intensified OTJ training of going thru different phrases to become a Machinist, only then the learning really starts when that person is selected in a particular area where management felt he will fit, only then he can get past the surface and get into the nitty gritty. Without passion, some will only treat their work simply as a job. Additional Nuke qualification or becoming a Toolmaker aside.

That is akin to Martial Art's first level black belt after years of training - if not knowing the first degree just shown that person has learned the basic, ignorant ones will think they've gotten the magic and not realizing their glass is still yet half empty!

I will end these and let someone else contribute something technically valuable to the subject at hand that I may also learn from.

 

What the hell is going on in here?

 

DITTO lol

 

The forum has been dry lately so Victorf and I are spicing things up by arguing if you can tighten intake bolts properly without a torque wrech. The accountant (me) says yes. The machinist, VictorF, says you cannot.

Victor is of course more experienced and correct about his comments. I say in this instance I can be good enough w/o a torque wrench (particularly since one won't fit) and my experience has proven me correct in my case. Users will have to make their own decisions and their results may vary. Lol.

If you choose to use a torque wrench I will repeat my caution to be careful in the inch lbs setting...a cheap torque wrench may not be accurate at such a low torque value and if you snap that bolt it's going to be a bear to remove back there.

 

well I ended up drilling 2 pilot holes just big enough for me to get a 1/4" extension through, connected to my 5mm, and torqued to spec. At this point I'm in WAY over my head with what I've spent on the car so unless someone with money REALLY likes stroked out 98's I will have her for a while... As long as the engine torquing around doesn't loosen my Y fuel fitting that intake won't be coming back up for a while.

 

Well put Joe-G! It all boils down to personal preference.

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When people asking questions, IMO, correct information will enhance their experience and skill. Ultimately, its up to the end user how to use that "established" information, in this case engineered torque specs.

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A little Trade knowledge (from your humble retired Nuke Toolmaker, kept the "Ships Fit To Fight" for 39 years) to share and for those who care:

1. "O" ring type seals require only .005" of compression to be effective! For reference, a piece of ordinary paper is .003" thick.

2. "O" ring groove for "O" rings have painstaking machined .003" radius corners, then mirror polished for pinch/cut prevention. Requirement is the same for both directly machined onto a piece or die making.

3. Proper sealing function and longevity for the "O" ring as well as the components using the "O" ring must be parallel and square during the sequence of torquing - torque specs are normally provided to achieve the .005" compression.

Given the above simplified notes, if torque is done by hand, will that joint be compromised and not able to seal? Probably not!

But torquing by feel for sure will likely cocked the two components. High probability of damaging the plastic IM and for sure life expectancy of "O" ring compromised.

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Now, Fast IM comes with installation direction with high lighted bold warings. It is recommended to torque in an crisscross fashion - torque spec is 70-89in/lbs.

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Proper torque wrench is a story in by itself. I leave it at that!

Like I said, do what you like!

 

how is everyone torqueing the rear most bolts on the fast 102? I cant get a torque wrench and socket in back there!

 

If you can't get a wrench back there, you should be able to get very close based on the feel from torquing the other bolts. That's what I have don't in the past.