Munson

hey, i am curious about what exactly i can do with lt1 edit ive searched and havent gound a whole lot about it.. I have an idle problem with my car along with me thinking its running rich.. Can I diagnose whats wrong with it using lt1 edit?

Injuneer

LT1_Edit is programming software. It is not diagnostic software. The OBD-I version (94-95) comes bundled with pcmcomm diagnostic software, but the OBD-II version (96-97) does not include anything for diagnostics.

You could get AutoTap for OBD-II diagnostics.

http://carputing.com

http://www.autotap.com/

Dan Parker '96

LT1 Edit is quite good on the engine side of OBDII. It's fairly good on the A4 transmission side.

They've given up progress on the '96 OBDII vehicles. LS1/2 is now their focus.

It's tough to get tools for a five year old span platform.

Munson

the only dyno car performance place in town doesnt deal with lt1's.. What could I use then to figure out these idle problems then? Would this auto tap tell me the problem? My car isnt giving me codes for it..It does have the stock plugs in it still.. i ordered some ngk ones and new plug wires although i doubt that will help... Ive done everything from adjust the egr, adjust the throttle body screw checked voltage on wires... im tired of playing the guessing game with it..

Munson

i thinki asked that question too soon.. Autotap seems to be what im looking for.. which one would you guys recommend for this problem? that or lt1 edit?

Injuneer

Did you read what I wrote? LT1_Edit is programming software. AutoTap is diagnostic software. LT1_Edit is good for reprogramming your PCM. AutoTap is good for pulling diagnostic codes, and monitoring the various sensors and PCM operating parameters.

All you've told us so far is you have an "idle problem"..... what is it? Rough idle, incorrect idle speed, surging idle speed, knock retard at idle? The more you tell us about the problem, the easier it is to tell you how to go about solving it.

By looking at the PCM with AutoTap, you can look at things like the IAC counts to determine whether the IAC motor is responding. You can watch the MAP to see if its causing the idle problems. You can check to see if the TPS voltage is correct an within the PCM's required operating range. You can look at the long term fuel corrections to see if the PCM may be adding fuel the engine doesn't need. You can determine if you have a problem with "split" long term corrections (BLM's).

Wouldn't make much sense starting to reprogram the PCM, until you figured out what is causing your problem. But is could be issues with cam overlap that may only respond to adjustments to the timing, idle speed, etc.

You need diagnostic software before you need programming software.

Munson

i guess there isnt a program that does both this could cost me alot of money!

Munson

as for the problem ive had it since the engine work was done. the car does have a simple mail order tune from pcm for less.. If the car has been sitting for a day or so atleast long enough for it to be completely cold when i start it up it will crank up to about 1400 rpms or so then fall back off down to say 500 even lower sometimes it will bounce back and forth from low rpms to high rpms.. It does this extremely where the car will even die.. However if i ease on the gas after starting the car and keep it at an idle for a minute or so it will even off at about 1000 rpms which im pretty sure is where it has been set to idle. in the beginning i got codes for MAF sensor malfunction and o2 sensors going bad which i got diagnosed at autozone.. i actually cleaned the o2 sensors and never got that code again(i dont have the rear o2 sensors only the ones in the collectors) The o2 sensor codes were displayed almost directly after the install was done i figured it was from the new headers... The MAF code that i got happened a little later and it seems like it doesnt appear when i let the car warm up.. but after a little while of helping the car get to idle it will idle fine IN park.. however, while driving around when im comming to a stop the rpms will fall off to about 5-600 again if i come to a quick stop.. another thing that bothers the idle quite substantially is using the air conditioner. Hope this gives you some idea of whats going on here

btw: i have checked the tps voltage maf wiring, connections etc.. and could not find any problems. I have also adjusted the throttle position screw with some luck but it seems to be a false cure(just helping the engine idle higher)

Munson

anyone with a problem similar to this?