Beaver Posted October 16, 2009 Share Posted October 16, 2009 hey all. the girlfriends car is packing a sad. have tried fixing it but i dont know enough about efi systems and ecus lol. its a 1994 libero, 1800 and has a surging idle. gotten to the point where she just wants its fixed. so yeh, anyone on here a mechanic and can do mate rates? haha cheers Quote Link to comment Share on other sites More sharing options...
shizzl Posted October 16, 2009 Share Posted October 16, 2009 just check all the vac lines first.. and theres shit loads of mechanics in chch..lots in the yellow pages.. Quote Link to comment Share on other sites More sharing options...
dirty_leppa Posted October 17, 2009 Share Posted October 17, 2009 try getting some contact cleaner and giving the airflow meter a clean. also check the coils and plugs are not stuffed. maybe check the oxygen sensor to. Quote Link to comment Share on other sites More sharing options...
Bling Posted October 17, 2009 Share Posted October 17, 2009 0800 Car Tune - Graham, good sort Workshop in town, but also does mobile work. Quote Link to comment Share on other sites More sharing options...
Beaver Posted October 17, 2009 Author Share Posted October 17, 2009 try getting some contact cleaner and giving the airflow meter a clean. also check the coils and plugs are not stuffed. maybe check the oxygen sensor to. ive had a good fiddle/nosey, but im stumped. when i unplug this thing (see photo) it stops surging but idles at like 2000 and i cant adjust it any lower. so i got a second hand one but the exact same thing happens......it attaches to the throttlw body, and kinda hooks onto the butterfly shaft and i assume its the electric idle control but yeh im stumped. figured it must be something deeper in the computer so in my mind it rules out vacum leaks or air flow meter as surely if it was either of them then it would change when i unplugged that thingy ma bob Quote Link to comment Share on other sites More sharing options...
shizzl Posted October 17, 2009 Share Posted October 17, 2009 thats a throttle position sensor (TPS). doubtful that it would be faulty anyway.. Quote Link to comment Share on other sites More sharing options...
Beaver Posted October 17, 2009 Author Share Posted October 17, 2009 thats a throttle position sensor (TPS).doubtful that it would be faulty anyway.. ah that makes sense, was only 20 bus for another one so no biggy . so it must be something that gets the info from the TPS and adjusts the idle accordingly thats fucking out. was told it will most likely be the idle stepper motor and fuel (chur bro) sent me some real good links, but the info they gave me doenst quite match up with this engine. there is another big ass thing attatched to the trottle body underneath at the back, which when unplugged has no effect...so yeh im stumped. Quote Link to comment Share on other sites More sharing options...
dirty_leppa Posted October 18, 2009 Share Posted October 18, 2009 i very much doubt its the ecu itself. if you can get hold of a service manual for this engine, it may be able to tell you how to chech the ecu for fault codes and this should point out exactly what is wrong. failing that take it to an auto sparky and they should be able to tell you pretty fast Quote Link to comment Share on other sites More sharing options...
Beaver Posted October 18, 2009 Author Share Posted October 18, 2009 yeh the gf is getn prety shity at me for not being able to fix it lol so i just told her to take it in and get it done herself haha Quote Link to comment Share on other sites More sharing options...
Gaz Posted October 18, 2009 Share Posted October 18, 2009 Check injectors boss. I'm no pro but my theory would go like this: If you put larger/too big injectors in your car it surges. If you had a blocked, or semi blocked, injector the ECU may be compensating by cranking up the duty cycle causing too much fuel from 3 injectors and just the right amount from the blocked one. This would in theory cause your surging. Im' not really sure but could be a place to check? Others will prob tell you if im all shit. Gaz Quote Link to comment Share on other sites More sharing options...
Beaver Posted October 18, 2009 Author Share Posted October 18, 2009 Check injectors boss.I'm no pro but my theory would go like this: If you put larger/too big injectors in your car it surges. If you had a blocked, or semi blocked, injector the ECU may be compensating by cranking up the duty cycle causing too much fuel from 3 injectors and just the right amount from the blocked one. This would in theory cause your surging. Im' not really sure but could be a place to check? Others will prob tell you if im all shit. Gaz hmmm i can see that causing it. its just the whole unplugging the TPS stops it surging, but its worth a look. now that you mention it, i found a bottle of injector cleaner stuff in the boot when i was chucking some sounds in.....ill tell her to chuck it in the tank when she puts gas in Quote Link to comment Share on other sites More sharing options...
japawagons Posted October 18, 2009 Share Posted October 18, 2009 Unplugging the TPS would stop the engine from surging because the ecu would switch to limp home / open loop mode. That usually increases the idle etc. Sounds like you've got an air leak or something, and the increased idle would compensate for that. Quote Link to comment Share on other sites More sharing options...
Beaver Posted October 18, 2009 Author Share Posted October 18, 2009 Unplugging the TPS would stop the engine from surging because the ecu would switch to limp home / open loop mode. That usually increases the idle etc. Sounds like you've got an air leak or something, and the increased idle would compensate for that. doesnt limp mode drastically reduce the power? when its unplugged, apart from the higher idle (around 2000) it drives perfectly normal. ive checked the vac lines from the throttle body and intake mani and am prety sure they are all sweet Quote Link to comment Share on other sites More sharing options...
shizzl Posted October 18, 2009 Share Posted October 18, 2009 its a mitsy, they come standard with reduced power... to me it does sound like a vac leak Quote Link to comment Share on other sites More sharing options...
Beaver Posted October 18, 2009 Author Share Posted October 18, 2009 its a mitsy, they come standard with reduced power...to me it does sound like a vac leak haha fair call. should i be looking else where apart from throttle body and intake mani? also, apart from thorough visual inspection, is there a better way to check for leaks? Quote Link to comment Share on other sites More sharing options...
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