98SN95

Been having some issues lately, when i leave for work in the morning, after the ten minute drive down the interstate at 70,the first stop i come to the car starts idling around 1500 rpm, the only way to get it to stop is to turn the ignition switch off and then back on, also my cooling fan comes on anytime the key is turned on, was thinking it may be the CCRM?

98SN95

BUMP=

cliffyk

99.44% of the time idle problems are related to the IAC, mostly because as the name implies that is what controls the idle--the CCRM has nothing to do with idle speed.

As to the fan running all the time, that could indeed be a CCRM related issue. Though the PCM commands the CCRM relays to run the fan in low or high speed. If the relay contacts were fused together the fan could run all the time.

98SN95

just changed the iac, no change in the idle problem, also my a/f is really lean at wot, its at 14.9-15.3 and thats with the fuel modifiers for low thru high at -1.0!!!

cliffyk

Are you 100% certain you have no unmetered air getting in to the intake, and that there are no exhaust leaks before or close after the front O2 sensors?

What does the fuel rail pressure look like when you are at WOT?

Also, at 14.9:1 to 15.3:1 at WOT the engine should be pinging like heck--is it? If not then the spark is either remarkably retarded or the WB meter is not accurately reporting the AFR--what brand is it, where/how is the sensor mounted?

98SN95

okay since my last post i have changed my global fuel pt and ft to 1.2 and my fuel is now reading 12.7 at wot, the wideband is aem and mounted where my rear o2s would be, i have not changed the spark setting at all, i am running the msd coils and wires, plugs gapped at .060 ngk tr55, at one point before i got the tuner, i did think it was pinging going up a bridge but otherwise rite now i dont hear any pinging

cliffyk

That (1.2 for the PT and FT settings) sets a +20% decrease in the low and high injector slope values (telling the PCM the injectors are smaller causes it to calculate a longer injector pulse to reach the target AFR).

This says to me that the injector size selection, and the MAF transfer function are not matched.

Excuse me if I missed it in a previous posting, however what size injectors do you have and what size did you select in Special Forces--also what MAF do you have and what did you select?

98SN95

all stock 98, maf, injectors, and as for the options on the tuner they are all set to stock, maf, injectors. now i do have version 2.3 without the update, so i believe the global pt and ft are backwards right?

cliffyk

They are not really "backwards", however the labels next to the selection boxes (+ to lean, - to richen--when the values are 0.5 to 1.5) are pretty much meaningless. The documentation does correctly state that values < 1 lean the mix and value > 1 richen it.

The value selected is applied as a divisor to the low and high injector slopes--so for example if you had 19lb/h injectors and selected 0.9 as the FT modifier the high slope would be set to 19/0.9, or 21.1lb/h. The PCM would now believe that the injectors were larger than they really are and use a shorter pulse to inject the desired amount of fuel.

But the injectors really aren't lager so the shorter pulse = less fuel = leaner.

Going the other way as you have done, 19/1.2 = 15.8lb/h. The PCM now thinks that the injectors are smaller and lengthens the pulse width to get the desired amount of fuel--but again they are not really smaller so the longer pulse = more fuel = richer.

How does the car run on the stock tune?

98SN95

it was running good, didnt have the wideband so dont know what the a/f was, drove it for 8 months without any other mods except the pi swap. I checked my exhaust a little while ago and found a very, very small leak at the donut on the driver side. Also i had removed my maf screen and couldnt get another one so i used some window screen from home depot. I was wondering what effect the timing has on a/f?