Help please!
 

Ok, so i think being as specific and detailed as possible will give me a better chance of finding out exactly what the problem is.

I have a 1998 Saturnhttp://images.intellitxt.com/ast/adT...lass_10x10.gif SC2, with 172000KM/'s. Its manual transmission.

2 weeks ago i replaced my spark plugshttp://images.intellitxt.com/ast/adT...lass_10x10.gif, wires, and air filter(changed to a K&N that fits the stock airbox). Ive since driven 800-1000 km's since then with no problem actually a huge gain in engine responsiveness. I had a long drive to make and i ran 94 in it. And i just filled up last night and the gas station had 91 octane for price of 87. so i filled up.

I drive to work this morning fine and home fine. i couple hours went by, and then i went to get in the car. it should have been cold at this point. the car cranks over starts, revs to 12-1400 rpm, drops to 600, then stalls. It does this repeatedly until i put my foot on the gas rev it at 2000 for a few seconds then slowly let off the gas until it idles, and then it idled normal, i gave it a shot of gas and it revs up, then stalls. I also noticed a build up of Soot like buildup on the very tip of the exhaust.

I replaced the ECTS. The car now starts and idles at about 900, but drops to 600 often. I took it for a little drive and found if i let off the gas it will stall in gear. If i stay on the gas its fine, i shift quick and its fine. if there is any pause in the shift the rpm drops significantly. But i can still make the shift. If i put it in neutral and come to a stop it runs at 600rpm.

PLEASE HELP!!! ive thought of changing the TPS, CPS, and MAP. Should i?

you should check and make sure your idle air control selonoid isnt dirty.also check for vaccum leaks cuz if your car is running lean from a leak the computer will sinse that and boost up fuel psi which will make it run rich(which might explain why you have soot on the exh tip/...just a thought...good luck

is there a common place for a vaccuum leak? and pointers for finding it?

take some soapy water in a spray bottle start the engine and spray it all around the intake,thottle body mounting,vac hoses,line,etc..if the engine rpm changes then chance are you have a leak...

use throttle body cleaner instead---you don't want water in your intake or anywhere else.......

Water ................. you have to be kidding.

I really don't think he was kidding.......bet he has a whole back yard full of hydralocked vehicles from when he was using the power washer piped through a bottle of dish soap to check for vac leaks....

Now that he's scaled it down to a spray bottle he just lightly rusts everything inside and out....

First of all i said use some soapy water and just spray around joints and hoses where vaccum is present i didnt say take the hose and spray your engine morons,,im ase cert tech i know what im talking about,it will not hurt anything or cause any rust at all...but dont take my word for it,just take your car to one of the jackasses on this thread,im sure they could help you...and excuse me for trying to help a fellow saturn owner!!!

Which jackass on this thread are you referring to?-- there are several......

By the way, mr. aircraft doctor, your improper use of punctuation is most troublesome; never seen a double comma used before....

Dude, lighten up.