Here is an attachment of my datalog from winaldl It runs fine for a little while then it starts surging. I know its kinda hard to read in notepad but for some stupid reason I cant get it to open with excel. Can someone tell me what might be causing the surging. I have gone through every sensor already and the 02 is new. this was takin while in park and after the engine had been warmed up. Also as soon as it starts doing it the old high gear, closed loop flags come on.

 

Nobody knows how to read this and figure out what is going on?

 

camok5

Your log is indicative of start-up log. Your car was already warm - CTS is around 85C which is normal. With engine start - it was operating in open loop OL for about 43 seconds. After 43 seconds ECM switched to close loop CL and BLM indicated slightly rich condition typical of an engine just coming from a start. Once in CL your idle speed is a bit bouncy between 525 and 750 RPM. This could be due to IAC steps in 30 to 50 range. This is too much for fully warmed engine. Reset IAC https://www.thirdgen.org/tpimod2 Check for vacuum leaks around TB and vacuum lines.

Your NBO shows normal swings between 0.040 and 0.850 Volts - It is showing slightly rich condition. BLM dropped from 125 in OL to about 112 in CL which indicates that ECM is taking out fuel. Check for vacuum leaks which may cause some of this idle hunting.

Alternator appears to be OK - 13.5 Vdc

//RF

Your TPS sensor reads 0.7 Volts which is OK for idle position.

 

I checked my IAC and it is set fine stayed around 450 rpm. I have checked a few times to try and find a vacuum leak but cant. The only wierd thing is that I'm not getting any vacuum out of the front bottom port on the tbi but the one above it is fine?

 

I replaced my IAC and that didnt help also I figured out the problem with the front lower vacuum port but that didnt help either. Anyone else have any ideas? I have gone over everywhere looking for a vacuum leak but cant find one.