mrfred,

Please report how tuning goes on 3dman1's car, very curious what you find. I'm looking at the intake for my own car and that is a common part between the cars. Hopefully its just the shield which I plan to source if I get the primo intake.

 

I am having this same issue I believe on my car. It basically falls on its face at around 2k rpms. Car zeros out "---" (lean) on the afr gauge and starts to bog/stall and then it will run normal once it gets past this spaz out mode or w/e it is doing. It will only occur for a sec or 2 (its worse in higher gears i.e. 2 or 3 havent bothered to see how it acts in 4th or 5th cause im assuming it will only be worse.) Car was tuned at AMS and they cant figure it out. Im talking to Mitch about working on a diff. map through my cobb, but regardless I have an appointment on the 5th of Oct. so they can diagnose the car themselves. Its very frustrating cause I can take the car to redline and not have any issues with the afr's or the car bogging or stalling.

 

I have a similar issue with that RPM range.

It sounds like a different concern, but the RPM it occurs at is very similar. I haven't really looked into it, I never noted it as a lean out issue. On mine, partial throttle will fall on its face around 3200 RPM. I'm on stock turbo though. WOT and anything above about 60% seems to be fine, it's just that area around 30-50% throttle.

You've reignited the desire to fix it, so I'll dig into it a bit too. If you come up with a solution, I'd love to hear it. Maybe it will translate to my "hiccup".

 

I have this issue around the same time each year, but I never get as lean as you all. It usually goes anywhere from .5 to 1 full AFR point. For example, I will run 11.2-11.5 AFR all year, then all of a sudden from 3000rpms to 4000rpms it runs around the 12.0 AFR range and then it goes back down to the low 11s after 4000rpms.

 

I wouldn't worry to much about that. Could just be changes in the weather. Considering when the temperature drops the air will be colder which in turn means it will have more oxygen.

 

Yes but the ECU should compensate for changes like that.

 

Your right it should, but again I wouldnt worry about it. Just be lucky that your not dealing with what my car is doing. I wish my car did what yours did at this point.

 

Have you swapped relays and injectors? It sounds like an injector issue.

 

ive got the same problem on my 08 GSR. from 2-3k with 30% tps or so, my afrs will do this:

15.7
16.2
16.2
17.5
18.4
17.4
17.4
15.9
15.5
15.5
14.4

so do we simply drop the crossover point for the open loop load from the peak values of 140 down to 70/80/90?

the load cells i hit for the above afrs are:

87.5
88.4375
89.6875
90.9375
92.8125
94.0625
90.3125
91.25
95.9375
98.4375
100.625

 

Well, I can also say I experience this issue and get some pretty lean issues between 2000 and 3000 rpms. It has seemed to have gotten slightly worse lately possibly a little to do with temperature change in the mornings but it is there all the time.

I have a stock intake so that can be ruled out, the only aftermarket parts on my car are a turbo back AMS exhaust and a GS 3-port solenoid. I wonder if it’s more related to an accel issue with the TPS. Have there ever been tables found on the X to tweak them a bit? I can constantly initiate it with throttle input over and over and over again on command. Running through the area of the map it does go leaner also but TPS really seems to set it off to where I can get it to hit high 17's and even 18afr if I initiate it just right. I realize the wideband probably has latency and the modulation and fuel cutoff may be causing it to look much worse vs. running through the problem range but I think there may be a solid relation there.

I've richened the areas a little bit where it's happening and it doesn’t seem to really help. I have not played with MIVEC nor have a changed the open loop crossover point. I was hoping someone more experienced that has seen this may have updated some findings before I did to much more. Time has been tight so I haven't messed with it for a while.

 

Sorry I've let this thread stew for a while, I have made a few changes to the car and the issue is *MUCH* better now. Daily driving it is basically not there. However, it was when i was at the track doing autoX runs when I noticed it the most, and I haven't done that in a while, so please take this with a grain of salt.

First up, I changed the open/closed loop cutover to ~80 in the problem area. This seemed to help.

Also, I have a Primo 3.5" intake, no heat shield. I decided to take my stock exhaust manifold heat shield and put it to use....and wrapped it around the filter on the end of the intake. Not tight, just enough so that it would act as a shield. This helped a ton. I had to tweak AFR map richer to compensate, the car was going lean at WOT. After that and some driving, the issue seems to mostly have gone away. Even with AC on but I should note that it is much better even w/o AC on which is why these heat shields seem to exist in the first place.

Now last thing I changed is the intake manifold. I still have the 100% stock unported TB but I swapped in a MAP Rev3 ported intake manifold.

As I'm writing this I just realized something else! When I was putting the IM back in, I think I inadvertently swapped the ports that the EGR and BOV use. This really shouldn't matter but....worth trying!

I hope this helps guys, I really am not sure if one specific thing fixed this for me. Try the open/closed loop cutover and the bov/egr port swaps, those are free and easy!

 

I definitely don't want to do this if I can help it. I have been bugging 3dman1 to make a heat shield or cold airbox, so maybe I can finally get him to do it based on your experience.

 

I should have mentioned the mods i have on my car. Synapse intake, BOV and piping. Grimmspeed 3 port and turbo XS dump and full exhaust, FIC1100's, works fuel rail, arospeed fuel pressure reg and guage.

I also changed over my crossover point to 80 last night for 5 tables (stock from 89 and up, i think it was the 1500 table to the 3500 table)

the problem for the best part went away, It did however lean out on a very small amount of throttle, with a really low load cell, but once it got to a little bit of a higher load cell the AFRs were spot on and no hesitation 17x afr lean out. I do need to scale my MAF, but was having trouble getting my maf tables to show up in ecuflash for my rom

so basically, getting the car off the line with small throttle, problem is fixed as it now aims for the normal fuel table.

 

I forgot to ask this, but anyone else with this issue, please describe your intake setup in detail, including if you have a heat shield or not.

FWIW I'm still getting 19mpg.

 

I'm on the 100% stock airbox and filter. I ordered a Primo 3.5" intake that I hope to be getting in the mail any day now though. I am also going to order an AMS shield since Murlo rocks one successfully.

I'm still slightly weary of the MAF scaling since I have never done it before... wish I had something to look at for a reference or close starting point. My X is my only car right now because my Evo 8 is down so I have to learn it and get it right the first time lol

This issue has also made me a little concerned since a couple people with the most notable issues have Primo intakes... My issue put me a little more at ease since I have a stock setup with the problem but whos to say it wont get much worse after the switch.