Ok, I have a new update with my testing that will shed even more light on this stuttering issue.
I have been playing with modifying the stock MAF and I have gotten rid of the stuttering issue!
Remember that I have the bigger 24# injectors in the car before anyone jumps up to do what I am about to tell you.
First off, I have two stock mass airflow units so I decided to play around modifying one. I took the extra maf and drilled the rivets off of the backing plate that covers the sampling tube.
The sampling tube has a 90 degree downward turn in it, and the backing plate is easily removed. With a small drill bit I drilled holes in the center of the rivets. Then I took a larger bit that was sized pretty close to the rivet diameter. Then I drilled them off. With the plate removed, the sampling tube is a straight shot and no longer had the 90 degree turn.
I reset the memory on the pcm by pulling fuse #4 (3 amp) out while I was working. Then I put the maf back in the car and reinstalled the fuse.
I fired the thing up and the idle fluctuated for a few moments and then leveled out. By monitoring the fuel trim I was able to tell that it had apparently richened up the airfuel mixture.
When I did this I was hoping to increase the air velocity going through the tube. I don't know if that happened, all I know is that the stuttering was completely gone once I did this.
By drilling the rivets off, you can actually re-attach the plate if this does not work.
I reccomend that someone with a 2000 SVT that has a stuttering problem and some time to play with their car, trying this.
For myself I went ahead after this test and removed the center post entirely and polished up the casting where it was at. The sampling tube is there, but it now looks sort of like a pro-flow maf tube.
For the SVT's running 19# injectors, DON'T remove the center post entirely. With my 24# injectors in it seems to be running lean at the top end now that I have the center post fully removed. The low end feels great now, and the injectors long term fuel trim has been increased.
For me, this is just a temporary measure until Friday when I get the GReddy eManage device. Then I will attempt to tune in one of the MAF's that I have. At least now I can drive normally around town!!
Good luck to those of you who are still having this problem. I hope this information helps you out a lot.
BTW, if you do any work on the MAF, you need to remove the electronics module from it. It uses something like a T-25 torx bit that has the center hollowed out. I just used channel-lock pliers to grip the outside of them and loosen them enough to remove by hand.
If you attempt this and it does no good, make sure you have two pop rivets and a rivet gun, or the ability to thread the holes you drill out and insert screws with loc-tite on the threads.
Good Luck,
warmonger
