hey everyone. this seems to be a decent forum with a lot of good information about...well...everything, ive already learned stuff i didnt know about my caddy. Ok, so i have multiple problems...hoping someone can help me out with 'em. First of all, the most pressing problem-whenever i accelerate from a dead stop, it seems to take my car a little longer than usual to get into second. I changed my filter and fluid not 12k miles ago, and checked it again this past weekend and it smells like tranny fluid always does, it looks like it's supposed to...i had a similar problem with a shift solenoid in a 97 chevy lumina, but i don't know if it's the solenoid, something screwed up in the valve body, or the transmission slowly tearing itself up. Sometimes, too, if i stomp the pedal down, i'll get the acceleration i want, but the car shakes and there's a not healthy "whump" sound (so i stopped doing that lol). Im going to assume i probably need to have it rebuilt, but i dont exactly have 1800 bucks to drop at my leisure. Next, i have a huge problem with getting consistent gas mileage. Sometimes ill thump out close to 19mpg/28mpg(city/hwy) for weeks at a time, and then suddenly, without warning, it'll drop drastically to like, 9/20. I have no clue what could cause this, i stay on top of tune-up, maintenance, filters, etc. I always run 93 octane Shell gasoline and occasionally dump in some Lucas injector cleaner. The only thing i can assume is i ALWAYS have code E30 (ISC RPM out of range...i think) in the computer. Im going to assume the ISC motor is the whizbang with the idle speed screw sticking out of it, this is the assumption i have came to after throwing my Chilton's manual halfway across my yard because of the vague descriptions it gives...there was another part that me and my dad replaced on it last year, i cannot for the life of me remember what it was, but i do remember it was on the back of the throttle body and required after replacement to go into the computer and reset some values...we never figured out how to do it so we just left it. I have no patience for mechanics, being that when i had the E30 code pop up LAST October (of 07) i took it to a mechanic, and his solution was to crank the idle speed screw all the way down and charge me 80 bucks for it, and then tell me he had no clue what was wrong with my car. Any ideas on all this junk? I appreciate any input you guys can give ***EDIT: I remember what that part was nowit was the throttle position sensor. The code i got was E70...which i still get on occasion =/

 

The problem is your TPS, it tells the computer where the timing should be as per your throttle position. If it is out of whack you will get less than original performance and bad gas milage. Try and set it somewhere in the middle position and then take it out for a spin as you adjust it little by little. The settings require a voltmeter and some patience to get it exact.

 

I'm not sure how you'd go about adjusting it...since the replacement part i bought from the auto store has no manual adjustment slot on the back of it like the original did. I remember asking them about it when i bought it, and they told me it was fine =/ suggestions?