T2 MSW Posted July 23, 2012 Share Posted July 23, 2012 After having the car mapped a couple of months back its been in the garage for a few weeks and rarely used. I took it out today to get the exhaust fixed as the vband failed and it wont run correctly. It wont idle from cold - AFRs are in the 16/17s when the car is warm it will eventually idle the 13s which is normal on cruse the AFRs are off the scale lean but then eventually will come back to about 14 When coming to a stop the car will stall with AFRs off the scale too lean However when on boost its fine 10/11 Ive checked all the pipes, fuel pressure, fluid levels basically everything I can think off. Anyone with any ideas, any help appreciated. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 23, 2012 Author Share Posted July 23, 2012 I think itmay potentially be fuel pressure. Its it normal for FPRs to adjust over time? the lock screw is fixed tight but at idle the pressure is dipping below 30 psi when I believe it should be at 40? Im going to test it at static in a minute Quote Link to comment Share on other sites More sharing options...
johnny g Posted July 23, 2012 Share Posted July 23, 2012 I believe Ryan maps at 3bar static. Have you also changed your TPS? - not saying that's it, I'm just throwing things out there! Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 23, 2012 Author Share Posted July 23, 2012 I believe it was at 3 bar static at mapping or just under 40 psi. Ive not changed the TPS no as it just seemed too random to be something so simple. The throttle can be off or at 1/4 and its still all over the place. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 23, 2012 Author Share Posted July 23, 2012 Its not fuel pressure. Static is 40 psi as it was when it was mapped. Only when connecting back up does the pressure drop to 30 as the afrs are so low Quote Link to comment Share on other sites More sharing options...
johnny g Posted July 23, 2012 Share Posted July 23, 2012 Is it a failing fuel pump? Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 23, 2012 Author Share Posted July 23, 2012 fuel pressure is stable it does not drop up and down at static?? Also should the AEM be getting AFR feedback? the AFR on the diagnostic screen just sits at 4.6 or 4.7 and never changes. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 23, 2012 Author Share Posted July 23, 2012 Im not sure if this is an issue or not but the AFR for O2#1 and O2#2 are really weird figures O2 1 never moved from 4.7 and 2 fluctuates between 4 and 9. None of those figures make any sense, it cant be reading AFR as I doubt the car would run that low and its not voltage??? Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 23, 2012 Author Share Posted July 23, 2012 100% not TPS as the ECU sees position no problems with no errors Quote Link to comment Share on other sites More sharing options...
johnny g Posted July 23, 2012 Share Posted July 23, 2012 Duff o2/wideband? Quote Link to comment Share on other sites More sharing options...
bignum Posted July 23, 2012 Share Posted July 23, 2012 I had an issue very similar to yours mike, turned out to be dirty/sticky injectors( was also parked up for a few months).it wouldnt hurt to run some injector cleaner through the system anyway, i ended up changing mine. - - - Updated - - - Duff o2/wideband? Hmm could well be that also. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted July 23, 2012 Share Posted July 23, 2012 Could be the AEM itself, I had problems with mine before doing all sorts of wierd things. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 23, 2012 Author Share Posted July 23, 2012 The AEM ECU or the UEGO? The AFR guage seems to work ok and the readings on the guage seem acurate. The readings on the AEM are all screwed up because the guage on the graph only goes from 4 AFR up to 9 AFR. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 23, 2012 Author Share Posted July 23, 2012 I had an issue very similar to yours mike, turned out to be dirty/sticky injectors( was also parked up for a few months).it wouldnt hurt to run some injector cleaner through the system anyway, i ended up changing mine Hmm could well be that also. Can I not see individual injectors on the AEM or is this the stupid 3 channel restriction? Quote Link to comment Share on other sites More sharing options...
mellonman Posted July 24, 2012 Share Posted July 24, 2012 i would of thought you would see then on the aem but only the voltage or single that the aem is sending to the injector its self ,so might not see a sticking injector. if its been sitting for a while you might want some fresh fuel in there Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 24, 2012 Share Posted July 24, 2012 Sounds like the AEM is getting an erroneously rich wideband signal and that's making it try to pull as much fuel out as possible. If you can datalog the O2 values you should be able to datalog the injector duty, that (combined with your injector size) can tell us if it's the ECU pulling fuel out. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 24, 2012 Author Share Posted July 24, 2012 (edited) Sounds like the AEM is getting an erroneously rich wideband signal and that's making it try to pull as much fuel out as possible. If you can datalog the O2 values you should be able to datalog the injector duty, that (combined with your injector size) can tell us if it's the ECU pulling fuel out. I can try and run a datalog tonight, im assuming I just run the car and then pull the logs from the AEM? I do think the reading on the AEM for AFR is a redherring as the scale on the graph for both O2 sensors stops at 9 AFR which is 5V!? i would of thought you would see then on the aem but only the voltage or single that the aem is sending to the injector its self ,so might not see a sticking injector. if its been sitting for a while you might want some fresh fuel in there Thanks for the suggestion but the Fuel is a week old Edited July 24, 2012 by T2 MSW (see edit history) Quote Link to comment Share on other sites More sharing options...
TubbyTwo Posted July 24, 2012 Share Posted July 24, 2012 what state is your ECU cooltant temp sensor in? This sends a signal to the ecu for cold start fueling. No idea if the supras are the same but when the same sensor broke on my MR2 turbo the car would not idle until warmed up without me holding my foot on the throttle. Once warm it was fine. Worth checking, on mine the wire connections had degraded fitted a new sensor £30ish and it was sorted. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 24, 2012 Author Share Posted July 24, 2012 what state is your ECU cooltant temp sensor in? This sends a signal to the ecu for cold start fueling. No idea if the supras are the same but when the same sensor broke on my MR2 turbo the car would not idle until warmed up without me holding my foot on the throttle. Once warm it was fine. Worth checking, on mine the wire connections had degraded fitted a new sensor £30ish and it was sorted. Did look at the temps for the coolant on the ECU last night and it was reading 171F which is about 77C and the Dash was reading 80C. However ryan did mention it may be worth changing it as it was getting warm on the dyno. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 24, 2012 Author Share Posted July 24, 2012 (edited) I have done a data log with that car just idling. AFRS are in the 16/17 range. Ill upload the data file now, would someone be able to help me analyse it?idle.zip Edited July 24, 2012 by T2 MSW (see edit history) Quote Link to comment Share on other sites More sharing options...
Yakky Posted July 24, 2012 Share Posted July 24, 2012 (edited) Water temp sensor will do bad startup fuelling if faulty at that range - makes big difference. It will be in warm-up until just below 80degrees. postscript - yes it sounds like it's flicking between warmup and full temp at that 77 point. Try new radcap with higher pressure slightly and new water temp sensor is money, but won't hurt. Not sure what you mean by "getting hot on the dyno"... the water?? It shouldn't barely creep above full temp a few degrees if that. Edited July 24, 2012 by Yakky (see edit history) Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 25, 2012 Share Posted July 25, 2012 A bad water temp sensor would make it overfuel, as it'd think the coolant is cold all the time and sit on cold start. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 25, 2012 Share Posted July 25, 2012 After having the car mapped a couple of months back its been in the garage for a few weeks and rarely used. I took it out today to get the exhaust fixed as the vband failed and it wont run correctly. It wont idle from cold - AFRs are in the 16/17s when the car is warm it will eventually idle the 13s which is normal on cruse the AFRs are off the scale lean but then eventually will come back to about 14 When coming to a stop the car will stall with AFRs off the scale too lean However when on boost its fine 10/11 Ive checked all the pipes, fuel pressure, fluid levels basically everything I can think off. Anyone with any ideas, any help appreciated. Just re read your original post and to me its sounding more like an air leak, first off, if it was fuel pressure it wouldn't run OK on boost, as fuel demand is that much greater, and more than likely where a weak pump or a vacuum leak in the FPR pipework would show up most, unless it was mapped like that. Secondly if it was down to the EC water temp sensor it would idle very rich as default , and not weak, it also wouldn't clear up at a certain temp, i suspect you have an air leak when cold and under high vacuum at idle, which is gradually sealing with heat, but still shows most at high vacuum, IE any time the engine is at low RPM/load. Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted July 25, 2012 Author Share Posted July 25, 2012 Just re read your original post and to me its sounding more like an air leak, first off, if it was fuel pressure it wouldn't run OK on boost, as fuel demand is that much greater, and more than likely where a weak pump or a vacuum leak in the FPR pipework would show up most, unless it was mapped like that. Secondly if it was down to the EC water temp sensor it would idle very rich as default , and not weak, it also wouldn't clear up at a certain temp, i suspect you have an air leak when cold and under high vacuum at idle, which is gradually sealing with heat, but still shows most at high vacuum, IE any time the engine is at low RPM/load. So based on this are you thinking air leak on the intake side? Only reason I ask this is the car has always sounded like on idle it sucks air through the filter on the idle control valve, then as the engine warms up it goes away. Its always done that so i never really worried about it Quote Link to comment Share on other sites More sharing options...
mellonman Posted July 25, 2012 Share Posted July 25, 2012 So based on this are you thinking air leak on the intake side? Only reason I ask this is the car has always sounded like on idle it sucks air through the filter on the idle control valve, then as the engine warms up it goes away. Its always done that so i never really worried about it thats normal mate if it has a filter fitted at the idle control valve,stock it go's back into the intake filter area so not much noise is heard, i think ricky's on about vacuum pipes maybe map sensor and fpr feed Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.