Neil-NA Posted October 19, 2011 Share Posted October 19, 2011 I have a 95 rav4 that has a hesitation around 1800-2500rpm only when cold, once up to temp it clears itself and drives fine. I have changed the plugs (old ones looked fine) tried 2nd hand leads (not 100% sure on the quality) and the coolant temp sensor. What else should i check i have been told to check for air leaks and replace the fuel filter, would either of these cause the hesitation when cold? Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted October 20, 2011 Author Share Posted October 20, 2011 Anyone? Quote Link to comment Share on other sites More sharing options...
straightsix Posted November 1, 2011 Share Posted November 1, 2011 You could try cleaning the MAF sensor. When was the last time the fuel filter was changed? There have been reports of fuel pumps that have started to fail which has shown up as hesitation. Why don't you buy my N/A engine and drop that in there instead? Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted November 1, 2011 Author Share Posted November 1, 2011 Not done the fuel filter yet, would the pump only cause a problem whilst its cold? I am thinking maybe it could be the 'other' coolant temp sensor or thermostat as it is fine literally the moment it gets warm, plus their's no warm air until it has warmed up then it gets roasting. Quote Link to comment Share on other sites More sharing options...
straightsix Posted November 1, 2011 Share Posted November 1, 2011 I'd check the other sensor then but the MAF is definately worth cleaning (gently!) Quote Link to comment Share on other sites More sharing options...
LOGIE Posted November 20, 2011 Share Posted November 20, 2011 (edited) what sort of milage has your RAV done? I bought a '99 RAV 4 about a year ago so as not to use my supra as a daily driver. It was very rough running at first and hesitating at about 2000rpm but it responded well to a good service I done the oil+filter, air filter, fuel filter and new HT leads (later models dont have Rotor arm and dizzy cap)and I changed the thermostat at the same time because I noticed it took a while to warm up (turns out thats quite common). Mine has now done 121000 and still runs great. Edited November 20, 2011 by LOGIE (see edit history) Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted November 28, 2011 Author Share Posted November 28, 2011 what sort of milage has your RAV done? I bought a '99 RAV 4 about a year ago so as not to use my supra as a daily driver. It was very rough running at first and hesitating at about 2000rpm but it responded well to a good service I done the oil+filter, air filter, fuel filter and new HT leads (later models dont have Rotor arm and dizzy cap)and I changed the thermostat at the same time because I noticed it took a while to warm up (turns out thats quite common). Mine has now done 121000 and still runs great. Sorry mate just seen this reply. The car has done 93,000 miles, as soon as i get it back from the garage (been in for a rather expensive MOT and have winter/ snow tyres fitted) i will do a service, i have the air, oil and fuel filters, plus oil, will get dizzy and rotor arm plus new leads and 02 sensor. I have been reading about similar problems on rav4world that suggest the engine needs a good de-cokeing. Can't do anything till i get it back so will wait and see what the eventual cause and fix is. PS, mine is a proper faggot chariot as its the 3dr version Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted December 17, 2011 Author Share Posted December 17, 2011 Quick bump for this. Any more ideas as to why it could miss when its cold? I pulled a fault code off a while ago and i am sure it said it was running lean, this all happened just after i had a new near full exhaust change, is it possible the 02 sensor has been damaged? although i don't see how as it has gone through a recent MOT. Quote Link to comment Share on other sites More sharing options...
Graham S Posted December 17, 2011 Share Posted December 17, 2011 Have you checked all the little vaccum pipes? Had one just last week that had similar issues, Found a tiny pin hole in one of the rubber pipes. Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted December 17, 2011 Author Share Posted December 17, 2011 Have you checked all the little vaccum pipes? Had one just last week that had similar issues, Found a tiny pin hole in one of the rubber pipes. Ahh never thought about that, could explain the lean fault code, will check them when i have a spare moment. p.s. any easy way to check them? Quote Link to comment Share on other sites More sharing options...
absz Posted December 18, 2011 Share Posted December 18, 2011 The coolant sensor for ecu will have two wires on it and the gauge sensor will have one,make sure you changed the correct one. leakage on exhaust system will also show a o2 sensor fault so make sure there are no exhaust leaks around the sensor area were air can be drawn in which will give the sensor a incorrect reading. Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted December 18, 2011 Author Share Posted December 18, 2011 The coolant sensor for ecu will have two wires on it and the gauge sensor will have one,make sure you changed the correct one. leakage on exhaust system will also show a o2 sensor fault so make sure there are no exhaust leaks around the sensor area were air can be drawn in which will give the sensor a incorrect reading. I have changed both coolant sensors, would an exhaust leak allow the car to pass an MOT though? The 02 sensor was checked and all was apparently fine. I still need to check all vac pipes. Quote Link to comment Share on other sites More sharing options...
absz Posted December 18, 2011 Share Posted December 18, 2011 With a exhaust leak the emssion lamda readings will be too high so proberly fail a mot test,if you do have a split vac pipes that can cause the fault as i'm sure that engine has a EGR valve,vac controlled. Quote Link to comment Share on other sites More sharing options...
Neil-NA Posted December 19, 2011 Author Share Posted December 19, 2011 With a exhaust leak the emssion lamda readings will be too high so proberly fail a mot test,if you do have a split vac pipes that can cause the fault as i'm sure that engine has a EGR valve,vac controlled. Yes the egr is vac controlled, I have found a nice write up on how to check if its working so will try it Tuesday. Thanks. Quote Link to comment Share on other sites More sharing options...
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