Now that I have a wideband I am able to see if my split BLM's were due to bad O2 sensor, or true split. Well I put it in Open Loop and I ran the WBO2 on the pass side 1st. Cruising and part throttle it stays from 14.4-15.1 pretty well, however I now switched it to the driver's side, and it has read up to 15.6 on part throttle. Comparing this to one of my last Datamaster scans, the BLM's seemed to show this split almost perfectly, reading 129 up to 136 on left, 125-131 right. So what could cause this condition, and how do I resolve this?

Possiblities I have thought of are:
1. Primary #1 slip fit leak (Hooker LT's)
2. Problem with plugs (running TR55 with 11.1 CR, ported heads, and E85 may be too hot of a plug)
3. Intake manifold leak (stock intake manifold, ported to 58mm openings only)
4. Tuning problem
5. Other.


1. I can try to seal the primary with copper RTV and clamp.
2. Have Autolite 104's at .038 waiting to go in.
3-5. Not sure how to find problem/fix?

Any help where to begin?? (other than #1 or 2).

Here is the DataMaster file: http://www.mediafire.com/?m4fnjewfmi9

 

Stock manifold is a pos and thats pretty much the root of it. Works good at very high rpm, not so much at idle and cruise.

Theres a whole crapload of things you can do to tune it in for it. Individual cylinder fuel trims is where you should look most likely if its at low throttle openings like 15% or less, somewhere in there. Honestly though if the blms are split and for a good reason, and its not over 5 or so apart under accel, just dont worry about it. Thats why it adjusts each bank seperatly. Although individual cyl trims will help you get it closer.