shizzl Posted February 1, 2023 Share Posted February 1, 2023 Hey all. need some further ideas to my issue. 4age fires up really nice, idles away at 2000rpm cold, then after a minute it starts hunting between 2-2500rpm. I’ve done the old brakeclean test around the manifold etc. this is running a map sensor. possible timing issue? Quote Link to comment Share on other sites More sharing options...
kpr Posted February 1, 2023 Share Posted February 1, 2023 They will rev cut if throttle is closed and revs go over x amount. if not running the water lines to throttle body, will idle higher when warms up. as uses the water temp to slow idle. might get away with adjusting idle screw or throttle stop. otherwise vac leak somewhere Quote Link to comment Share on other sites More sharing options...
mjrstar Posted February 1, 2023 Share Posted February 1, 2023 No jokes about doing a chassis swap to stop it being a hunter? It sounds a bit like a sticky iacv that is overcoming a spring, or target idle off from from actual idle trying to control ( this is what @kpris on about) but I'm not familiar with the 4age setup. What sort of frequency is it hunting, once every 2 seconds or every 10 seconds etc... You could check with a timing light to see if it's dancing around a bit, as a timing change at idle will affect rpm. / Do whatever @kpr said. 1 1 Quote Link to comment Share on other sites More sharing options...
shizzl Posted February 1, 2023 Author Share Posted February 1, 2023 Just got home from car club night, they said something similar. Sounds like they have wax or something inside the throttle body to help control cold idle etc. can block it off and manually set idle, clean it out etc. coolant system is clean as. but will throw it outside tomorrow and let it get to temp and see if it changes anything Quote Link to comment Share on other sites More sharing options...
Truenotch Posted February 1, 2023 Share Posted February 1, 2023 It could also be the throttle position sensor. They sometimes hunt when the TPS is set wrong. Here's a guide on how to set the TPS with a multimeter: http://www.matrixgarage.com/content/4age-tps-adjustment Quote Link to comment Share on other sites More sharing options...
thegreatestben Posted February 1, 2023 Share Posted February 1, 2023 I had a problem in my mr2 where the motor would hunt, it was small port head so was setup for power steering. Didn’t have power steering in the aw11 so had the idle up circuit looped. this made it really whack and the fix was to block both off instead of loop. Unsure if this is your scenario. Quote Link to comment Share on other sites More sharing options...
shizzl Posted February 1, 2023 Author Share Posted February 1, 2023 1 hour ago, Truenotch said: It could also be the throttle position sensor. They sometimes hunt when the TPS is set wrong. Here's a guide on how to set the TPS with a multimeter: http://www.matrixgarage.com/content/4age-tps-adjustment Legend, I’ll try this too. thanks Quote Link to comment Share on other sites More sharing options...
shizzl Posted February 2, 2023 Author Share Posted February 2, 2023 Update. seems to be sorted. took the throttle body off. found that the IAC was open venting into the intake. Removed it and made a blanking plate. gave it all a good clean out. got it back on , fired up and died. adjust idle stop. then fine tuned the idle with the screw. cheers legends 1 Quote Link to comment Share on other sites More sharing options...
ajg193 Posted February 4, 2023 Share Posted February 4, 2023 No IAC will make it shit on a cold morning. You might be able to free up the old valve by giving it a thorough cleaning, or just partially blocking a port off so it doesn't give so much extra air when cold. Quote Link to comment Share on other sites More sharing options...
shizzl Posted February 5, 2023 Author Share Posted February 5, 2023 Throttle control haha. it’s not a daily, so I’m not too worried about a lumpy cold idle. aslong as it runs and drives for now Quote Link to comment Share on other sites More sharing options...
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