danmanTSI Posted June 6, 2013 Report Share Posted June 6, 2013 Ok so some of you know that I have been having this problem for a while now. With summer here, I now have some extra time to work on the car and really just want to get it running right. The car is a pretty stock 84 other than the addition of an intercooler and stock diameter catless exhaust. My problem is that the car has a rough idle and misfires. the problem goes away any time the engine is under load, such as driving and using the a/c. I've read the codes and have come back with both vehicle speed sensor and o2 codes. (o2 code is still there with the engine at operating temp.) Also the car runs smooth when the engine is cold, but as soon as it reaches a certain temp the idle quality changes instantly. So far i've checked my timing, did a full tune up, replaced my o2 sensor, and replaced my confirmed leaky injectors with a new set of lsp replacements. The car only has 40,000 miles and has ran this way since I bought it at 32,000. I appreciate any help, Dan Link to comment Share on other sites More sharing options...
Shelby Posted June 18, 2013 Report Share Posted June 18, 2013 find and fix the reason for the constant 02 code and most likely your problem will go away Link to comment Share on other sites More sharing options...
traps Posted June 18, 2013 Report Share Posted June 18, 2013 cts or ignitor box? My car was all crazy and everything was getting replaced all the way the the ecu and learned the ign box eventually went out, I have seen bad cts sensors making it run rich with a sputter. Now ya did say you replaced the o2 sensor but did that make the code go away? Link to comment Share on other sites More sharing options...
Shelby Posted June 21, 2013 Report Share Posted June 21, 2013 to enter closed loop the ecu has to see a rich 02 sensor signal (above a .5 volt signal )and an above 140f temp reading , before that the engine is running on a preset map by tps and air mass an engine that runs good cold but not when warm is having sensor problems ,,now that does not mean a bad sensor, a broken wire will give the same result as a bad sensor , you can also have a bad air leak that leans out the over rich cold start and makes the warm runing worse Link to comment Share on other sites More sharing options...
Recommended Posts