2JZGE Na-T TT Ecu Mod
12-10-14, 11:26 AM
#2311
I was thinking that, but I've kind of had this even before I ever touched the tps or idle air screw. But its worth a try if I don't find any leaks.
And now I'm kind of unsure what to believe from the manual because some of it seems impossible.
And now I'm kind of unsure what to believe from the manual because some of it seems impossible.
12-13-14, 09:28 AM
#2317
I cut off the mustang flange, made the ffim a bit shorter, and had the q45 rmr flange welded on at the same angle to keep it straight when installed.
I have been doing some reading on the mr2 forums about USDM vs JDM ecu's.
The verdict over there is that the JDM ecu is more aggressive in timing and fuel maps.
There is a thread talking about if you don;t have 93 then dont switch to the jdm ecu.
specifically someone said if you have only 91 your knock sensor will hate you, which implies knocking.
I believe I am encountering that with my setup since I went FFIM the 91 is not agreeing with it so much.
someone on there said they just put a few gallons of e85 in which I was going to try so I will see how that goes.
My next thought is to switch to a usdm ecu and see if its any better on regular fuel. now I just need some 550+cc injectors and a usdm ecu and I can test it out. already have a map ecu I refuse to run the maf lol.
I have been doing some reading on the mr2 forums about USDM vs JDM ecu's.
The verdict over there is that the JDM ecu is more aggressive in timing and fuel maps.
There is a thread talking about if you don;t have 93 then dont switch to the jdm ecu.
specifically someone said if you have only 91 your knock sensor will hate you, which implies knocking.
I believe I am encountering that with my setup since I went FFIM the 91 is not agreeing with it so much.
someone on there said they just put a few gallons of e85 in which I was going to try so I will see how that goes.
My next thought is to switch to a usdm ecu and see if its any better on regular fuel. now I just need some 550+cc injectors and a usdm ecu and I can test it out. already have a map ecu I refuse to run the maf lol.
12-13-14, 10:54 AM
#2318
I'm surprised you would want to touch a usdm ecu after all the problems we have encountered.
I "fixed" my miss firing issue, re adjusted my tps and idle air screw. The car now idles much smoother (850rpms) now, but I'm essentially back to where I was before. Idling, rev engine to 2500 let off afr goes to 10.0 and engine bogs to near death.
I can't get a fuel pressure from the ecu so I would need a real gauge to check it. This leads me back to the problem where the fuel pump in constantly on with the key in the on position.
Also no vacuum leaks found anywhere. Any ideas on the fuel pressure? I've looked at alot of different threads on different forums but nothing really clicked with what I have.
I "fixed" my miss firing issue, re adjusted my tps and idle air screw. The car now idles much smoother (850rpms) now, but I'm essentially back to where I was before. Idling, rev engine to 2500 let off afr goes to 10.0 and engine bogs to near death.
I can't get a fuel pressure from the ecu so I would need a real gauge to check it. This leads me back to the problem where the fuel pump in constantly on with the key in the on position.
Also no vacuum leaks found anywhere. Any ideas on the fuel pressure? I've looked at alot of different threads on different forums but nothing really clicked with what I have.
12-13-14, 12:15 PM
#2319
there isn't anything wrong with the usdm ecu alot of cars use that and I am thinking its a little tuned down for our not as good gas which means it will be a little more forgiving for gas and na-t tune wise.
if the problem is related to the maf then it should eliminate it with the piggyback, if not then ill cross that bridge later. Honestly the best solution I have heard so far is to just fill my tank with like 1/4 e85 and 3/4 gas and it might just raise the octane enough not to have the issue anymore. I am going to do that later today and see.
do you have the stock fuel regulator and fuel lines, if so the fuel pressure is probably fine. the pump being on all the time will just return extra fuel to the tank and warm it up some but its not catastrophic generally speaking.
are you sure your tps works? as in the voltage changes as you turn it. something doesn't sound right from 2500 when you let off it should go lean for a second and then back to rich but not 10:0 rich.
i would think either the bov is letting some air out for it to overfuel that much (map sensor would help this situation) or the tps is not cutting fuel on deceleration which it should above like 12-1400 rpms.
when I rev mine up and let go it will go lean " - - - " on the wideband and then when it kicks back in it will be a little rich I think and then go back to 14-15.
My car was driving great a little while ago, I am really not liking this whole low octane thing.
if the problem is related to the maf then it should eliminate it with the piggyback, if not then ill cross that bridge later. Honestly the best solution I have heard so far is to just fill my tank with like 1/4 e85 and 3/4 gas and it might just raise the octane enough not to have the issue anymore. I am going to do that later today and see.
do you have the stock fuel regulator and fuel lines, if so the fuel pressure is probably fine. the pump being on all the time will just return extra fuel to the tank and warm it up some but its not catastrophic generally speaking.
are you sure your tps works? as in the voltage changes as you turn it. something doesn't sound right from 2500 when you let off it should go lean for a second and then back to rich but not 10:0 rich.
i would think either the bov is letting some air out for it to overfuel that much (map sensor would help this situation) or the tps is not cutting fuel on deceleration which it should above like 12-1400 rpms.
when I rev mine up and let go it will go lean " - - - " on the wideband and then when it kicks back in it will be a little rich I think and then go back to 14-15.
My car was driving great a little while ago, I am really not liking this whole low octane thing.
12-13-14, 12:20 PM
#2320
I'm positive the tps works, fuel lines and fpr are stock. I do get the lean right after the blip but after its done going lean its rockets up to 10. I can get a video of it, but I didn't want to keep doing it as this pretty much caused problems with my last set of plugs. Also the bov is recalculated and its a ssqv style bov.
12-13-14, 05:33 PM
#2321
I spent a couple hours looking for threads on something like this but the only thing I found is that it may have to do with the distance between the turbo and the maf and the distance between the maf and the actual throttle body.
So it's like my afr moves around at idle because its fluctuating with the metered air flow but it can never catch up. so they just go back and forth. So when you rev/ blip it goes rich then lean as you would expect but you end up with extra fuel?
So it's like my afr moves around at idle because its fluctuating with the metered air flow but it can never catch up. so they just go back and forth. So when you rev/ blip it goes rich then lean as you would expect but you end up with extra fuel?
12-14-14, 03:02 AM
#2322
are you sure your tps works? as in the voltage changes as you turn it. something doesn't sound right from 2500 when you let off it should go lean for a second and then back to rich but not 10:0 rich.
12-14-14, 03:07 AM
#2323
Ali Sc3: Maybe you can try bumping up your octane with Toluene or Xylene and see if the octane boost gets rid of the pinging? I think I read on Supra Forums that E85 might loosen some dirt in the old fuel system and clog injectors?
12-14-14, 09:10 AM
#2324
The tps works, ive checked the voltages and resistance and they moved appropriately when I moved it. I do have the map sensor spliced into the 5v + ground but it never caused any insane voltage drop.
Edit*- heres a video of what I'm looking at
Double edit- Before when i took the video it was idling high like 1100 rpm the entire time at full temp which is odd because it was at 850 yesterday. Went back out later after the video to look at vacuum lines and while the car was running at normal operating temp the idle just dropped from 1100 to 850 without me doing anything and it stayed there. Really confused by this one.
Edit*- heres a video of what I'm looking at
Double edit- Before when i took the video it was idling high like 1100 rpm the entire time at full temp which is odd because it was at 850 yesterday. Went back out later after the video to look at vacuum lines and while the car was running at normal operating temp the idle just dropped from 1100 to 850 without me doing anything and it stayed there. Really confused by this one.
Last edited by 187; 12-14-14 at 12:42 PM.
12-14-14, 01:18 PM
#2325
187, it has to get up to full operating temp and then go through a certain cycle with the afr before it will get to the learning part where it adjusts the iacv to idle down. thats what I mean by turn the screw a certain amount and then try it later because it does not adjust right away always. just go off your last setting and make tuny adjustments and test it out the next day and once you find it mark it on there.
I watched the video and to me it looks like you just have injectors that are a hair too large or its getting a little less air than it expects there (could be due to throttle body difference also). The wideband seems to be behaving pretty consistent and correct for closed loop so I dont think its tps either. I think when you do the blip when the fuel kicks back in its in open loop, and then it uses the o2 sensor to correct when it realizes its at 10.6 and way too rich so it drops to 16 quickly and then comes back to the correct value slowly, its how the ecu does it. your open loop value seems to be giving you 10.6 which I can see why it wants to stall. I would think it would do a lot better if it was in the 12-13 range. I don't think this one has to do with the bov since it doesnt have much load, but maybe the small differences between stock injectors and aftermarket or its somehow getting less air then expected from the maf reading is throwing off the open loop value.
maybe trimming the fuel back some percentage points would help with that, those areas are supossed to be rich but not so rich it stalls. the closer your open loop values are to what the original ecu expects then the less it will want to correct. they should still be rich though just like the stock ecu just not too rich and its common for this to need adjustment when messing with injectors. we think 550cc injectors and its that easy but they all flow a little different and maybe I am thinking the factory tt ones are a little less than 550cc. I would love to see a flowsheet number of an original tt injectors to compare to whats available but most people just handle it with a safc or if they want more features something more advanced to get rid of the maf also.
If you want to see generally how rich your car is running, then you can reset it one day with the o2 sensor disconnected, just disconnect the factory signal wire at the connector so it only takes a second. then see how rich it is when you start it and as it warms up. the car will still trim fuel according to the coolant sensor, but will not have the o2 sensor to go off of so its still in open loop. note down what the afr settles at when warmed up. Now if both of these numbers are very rich as in like the 10-11 afr range you would probably benefit from some adjustment.
The o2 sensor just cannot correct fast enough if your open loop values are too far off, so times when the o2 sensor is ignored (ecu coming out of decel fuel cut) it injects way too much fuel before the o2 kicks back in.
azn I am going to try bumping the octane up with e85, but it started snowing today so the SC is not going out.
I had mixed E85 once before and it seemed to drive great, but I had my stock intake on so I didn't have the issue at the time.
i wonder if its possible it already clogged an injector and that is what I am experiencing.
maybe a new fuel filter and larger injectors are in order for a test if the e85 doesn;t clear it up.
I am sure I will need the new filter though anyways if I put more e85 in there.
I watched the video and to me it looks like you just have injectors that are a hair too large or its getting a little less air than it expects there (could be due to throttle body difference also). The wideband seems to be behaving pretty consistent and correct for closed loop so I dont think its tps either. I think when you do the blip when the fuel kicks back in its in open loop, and then it uses the o2 sensor to correct when it realizes its at 10.6 and way too rich so it drops to 16 quickly and then comes back to the correct value slowly, its how the ecu does it. your open loop value seems to be giving you 10.6 which I can see why it wants to stall. I would think it would do a lot better if it was in the 12-13 range. I don't think this one has to do with the bov since it doesnt have much load, but maybe the small differences between stock injectors and aftermarket or its somehow getting less air then expected from the maf reading is throwing off the open loop value.
maybe trimming the fuel back some percentage points would help with that, those areas are supossed to be rich but not so rich it stalls. the closer your open loop values are to what the original ecu expects then the less it will want to correct. they should still be rich though just like the stock ecu just not too rich and its common for this to need adjustment when messing with injectors. we think 550cc injectors and its that easy but they all flow a little different and maybe I am thinking the factory tt ones are a little less than 550cc. I would love to see a flowsheet number of an original tt injectors to compare to whats available but most people just handle it with a safc or if they want more features something more advanced to get rid of the maf also.
If you want to see generally how rich your car is running, then you can reset it one day with the o2 sensor disconnected, just disconnect the factory signal wire at the connector so it only takes a second. then see how rich it is when you start it and as it warms up. the car will still trim fuel according to the coolant sensor, but will not have the o2 sensor to go off of so its still in open loop. note down what the afr settles at when warmed up. Now if both of these numbers are very rich as in like the 10-11 afr range you would probably benefit from some adjustment.
The o2 sensor just cannot correct fast enough if your open loop values are too far off, so times when the o2 sensor is ignored (ecu coming out of decel fuel cut) it injects way too much fuel before the o2 kicks back in.
azn I am going to try bumping the octane up with e85, but it started snowing today so the SC is not going out.
I had mixed E85 once before and it seemed to drive great, but I had my stock intake on so I didn't have the issue at the time.
i wonder if its possible it already clogged an injector and that is what I am experiencing.
maybe a new fuel filter and larger injectors are in order for a test if the e85 doesn;t clear it up.
I am sure I will need the new filter though anyways if I put more e85 in there.
Last edited by Ali SC3; 12-14-14 at 01:32 PM.