okay I just put in my new vacuum guage in my car. it is only pulling around 6 hg's. at idle, isn't that kinda low? but I do have a 306 cam.I have a bigger guage that I put right on the intake, it usually reads around 10-11 hg's. I can't seem to find the bigger one now, could I be losing some pressure with the 8 ft. of vacuum hose running to the guage inside the car?I know I don't have any intake leaks, I fixed them around 3months ago, not leaking a drop. and I can't find any vacuum leaks.

also I am getting a high map sensor code on my autoxray, it is fluctuating from 2.82-2.95 at idle, is that from the bigger cam? I have 3 map sensors here one is brand new and all are reading the same, I noticed that my map gasket is really worn out, fits really loose on the map tube, could that be the problem?

and finally my blm's on the driver side are sitting around 108, sometimes climbing to 116 and then sitting there, my pass. side bank pretty much sit's at 128's. my left and right integrators fluctuate from 116-136's but sit at 128's the most. any ideas on the left side? I have new ac delcos 02's. they both are reading pretty normal, constantly changing readings. could it be from the overlap of the cam? thanks for any help, Im pretty much at a loss on these issue's....

 

What is your timming set at idle? You might want to have around 31-34 degrees. What is your idle speed? Try 900-1100 rpm.

 

timing fluctuates from the lope, 21-25 degrees.
Idle fluctuates from 825-950 again from the lope I think.

 

Raise the timing to 31-34. Start with that first.

 

just curious what will raising the timing do? will it make the car run better, or just raise the vacuum? Im not very good at the internals of a engine... and can I raise it thru the tuning, even though Im a 93' speeddensity model?...thanks.

 

You'd have to change the timing with tuning software. As for the BLM's, you do know that 108 is the lowest value that can go, don't you? If you switch the O2 sides, does the problem follow? You may have a vacuum leak.

 

yeah I know 108's are the lowest. car seems to be running/idling/very little surging. I will try to switch the 02's. to see if that changes anything. im pretty sure no vacuum leak. Im pulling 10-11 hg's. on my vacuum gauge at my intake. and my map is reading around 62-65kpa's. which they seem to say it is about right for my 306 cam. Im being told now that 58mm. t.b.'s and a overlapping cam like mine could cause split blm's. hey sweetrod what is your vacuum gauge reading at idle in hg's. and what is your map reading. are you having split blm issues. tomorrow I will swap the 02's. my blms get closer when driving at all rpm's. within 5 blms of each other and hanging around 128's. so Im thinking it is overlap causing the split blm's.