89Cutlass Posted June 8, 2003 Report Share Posted June 8, 2003 I have been lucky with my 89 Cutlass 2.8l i bought of someones front yard for $750. Ive had it 2 years and since i have an error on the dash that normally displays the milage I have no idea how many miles are on itt and all ive had to do is put on new tires,brakes,plugs,wires change oil. besides other mods ive done for my own resons. But ive always had a little bit of a rough idle and and rough feel even in the seat of the car its great once your moving has tons of power. But when your sitting there or just barley moving in Neutral or Park its pretty rough. cant ever figure out were its coming from heres a list of new parts ive changed within the last 6months. Battery Alternator Plugs Wires Intake gaskets,and throttle body air filter catalytic converter(two weeks ago) thought it was that for a long time fuel pump cleaned throttle body twice IAC tranny mod valve ( the vacume line that goes from tranny to throttle body) thats about it. Guys please give me your info on what you would do. I love this car and i plan to keep it until it just wont go no more. Quote Link to comment Share on other sites More sharing options...
toastemcutlass Posted June 8, 2003 Report Share Posted June 8, 2003 possibly a vacuum leak? Quote Link to comment Share on other sites More sharing options...
89Cutlass Posted June 8, 2003 Author Report Share Posted June 8, 2003 actually i forgot to mention i changed every vacum line i could find including the ones under the plenum,egr,the 4 coming out of the throttle body. Im almost conviced its a coil pack. because the 2 plugs that come of one of my coils get a little white ashy deposits on them after a while. It could also be the 02 sensor but i dont think it could make it idle that rough and missfire. Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted June 9, 2003 Report Share Posted June 9, 2003 The O2 does play a part in fuel delivery, but it shouldnt make it missfire. Coil pack maybe. Have you done an idle relearn recently?? Sometimes, thats all it is, disconnect the battery for like 10 minutes, reconnect, the start the car, put it in drive, and sit there with your foot on the brake, for like 5 minutes, then turn it off. Restart it and you should be good to go Robby Quote Link to comment Share on other sites More sharing options...
JS91Z34 Posted June 10, 2003 Report Share Posted June 10, 2003 run a ohm test on the injectors and compare readings. I'll bet you have a bad injector somewhere. Quote Link to comment Share on other sites More sharing options...
89Cutlass Posted June 11, 2003 Author Report Share Posted June 11, 2003 The funny thing is its been like this since ive had it for 2 years and not really gotten any worse, and ive kept the car maintained good. Oil,plugs,wires,misc filters. Wierd ill try that idle relearn thing, but i think ive tried it before. Im thinking a coil. Quote Link to comment Share on other sites More sharing options...
89oldscutlass Posted June 11, 2003 Report Share Posted June 11, 2003 Wont a cam being worn out cause them to idle ruff like a sbc does.Have you checked your timing belt it might be stretched and need replacing.I seen a cam out of a 3.1 with a 100k plus miles on it and the lobes were about completly rounded. Quote Link to comment Share on other sites More sharing options...
89Cutlass Posted June 11, 2003 Author Report Share Posted June 11, 2003 these motors have timing chains and timing controled by the ECM and other sensors. Quote Link to comment Share on other sites More sharing options...
89Cutlass Posted June 11, 2003 Author Report Share Posted June 11, 2003 Hey how do you test the injectors i have an Ohm meter Quote Link to comment Share on other sites More sharing options...
Redfox340 Posted June 11, 2003 Report Share Posted June 11, 2003 Wont a cam being worn out cause them to idle ruff like a sbc does.Have you checked your timing belt it might be stretched and need replacing.I seen a cam out of a 3.1 with a 100k plus miles on it and the lobes were about completly rounded. Good idea, but on the 2.8L / 3.1L / 3100's there is no kevlar belt. Only a chain. 89Cutlass, you've done a ton... I wouldn't replace too much more unless you know for sure. The Ignition Control Module is a good guess, but check it out... I hate guessing games. - RedFox340 Quote Link to comment Share on other sites More sharing options...
89Cutlass Posted June 11, 2003 Author Report Share Posted June 11, 2003 see the thing is really the car is very dependable ive drivin over 1000 miles straight none stop only for gas and does great 30+ mpg dosnt burn any oil. but the damn thing shakes while its idling and worse in drive. its more of a thing now that i have to fix to prove something to myself. Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted June 11, 2003 Report Share Posted June 11, 2003 What about the TPS?? Also, if your running 87 octane, try 89, that soomthed my idle out and I get better gas mileage with 89 Robby Quote Link to comment Share on other sites More sharing options...
89Cutlass Posted June 11, 2003 Author Report Share Posted June 11, 2003 Im thinking i should take it to a shop and have them to a complete computer diag on it, that should tell me whats bad and whats not right ??? because i have a check for error codes and there are none. I no sometimes the sensors can be bad and not trigger the ecm. Quote Link to comment Share on other sites More sharing options...
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