First off i was looking at Knock retard and it showed 0.18 - 0.4*
some times what does that mean?

second i got code p0100 on the DTS screen it was something about my MAF

Third when looking at MAP what should i look at

Fourth how do i tell if i am running rich or lean

when i lookat at a 1\4 mile run my A/f went from 14:7 to 12:1 to 11:1 st the end of the run what does that mean??

 

Doesn't look like your gettin much knock retard. It's a good thing. Values lower than 100kpa mean there's vacuum. The lower the values, the more vacuum. You really can't tell much more than a general rich or lean condition from the stock oxygen sensors. 14.7 is stoic, higher is lean, lower is rich.

 

As noted in the post above, that is negligible.

What did the MAF gps numbers look like in the log? P0100 is "insufficient MAF sensor activity". Could be a deceased MAF. Could be a bent pin in the connector. Could be a failure in the pink wire to the MAF that supplies +12V from the fuse panel. That seems to be a problem that crops up in the 97's at times.

Was you SES light on at the time you did the scan? If not, it is likely that P0100 was a "stored" code, reflecting a past problem. Try clearing the code (pull "PCM BAT" fuse for 30 seconds) and see if it comes back.

First look at the barometric pressure (BAR). That will tell you the max pressure you can seen in your intake manifold, typically at WOT. Then look at the actual MAP readings. You should see a number around 35kPA (10"Hg) at idle with a stock cam. As you open the throttle, the MAP should rise, and at WOT should be within perhaps 5kPa of the barometric pressure.

Have you read my online scanner writeup?

You can get a very rough idea by looking at the pre-cat O2 sensor millivolts. When the engine is running in closed loop, the sensor mV's will be cycling rapidly from rich to lean. They should average 450mV during that period. When you open the throttle, the PCM should move into power enrichment (PE) mode and set a richer "target" A/F ratio. The sensors will stop cycling, and generally read relatively steady in the range of 850-930mV. You can sort of infer what the A/F ratio is from these numbers, but as noted in the post above, at the A/F ratios you need for peak power/torque (typically 12.8-13.2:1) the sensor are simply not very accurate.

The PCM can not read the ACTUAL A/F ratio. What is logged in AutoTap (or any other scanner) is the "target" A/F ratio..... the A/F ratio the PCM is using for its injector pulse width calculations. The typical target A/F ratio in a stock PCM program, at WOT will be about 11.7:1. That is just too rich for max power/torque. Simply altering the PE mode target A/F ratio more toward 13:1 is an easy way to pick up about 15HP on a stock engine.

 

JEBUS CRIST thanks for great response!

you cleared alot up for me, i will be checking my map too bar presure and try to read my 02 readings, when i get a good run and scan in all post it for ppl to take a look at


THANKS ALOT FOR YOUR TIME!

 

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