Losing boost at 6400rpm. Help!

[suprahero]

I belive I have been trying to help you with this since the first page....I know lol.

You're MAP sensors are not bad there just 2 BAR Absolute MAP sensors. Once you hit 1bar guage they are at 5V and will not read any higher. This is why you do not see the drop on the AVCR.

Jeremy

I've been using this 2jz map sensor for almost two years now, and it's always worked perfectly. I made 543rwhp @ 24psi with it. It worked fine in March when I dyno'd at 510rwhp @ 17psi also. This all started when I rebuilt my engine and put it back in. I'm just reusing the same 2jz 2bar map sensor that I've been using. Now I don't feel so good about it fixing my problem.

 

[IJ.]

I belive I have been trying to help you with this since the first page....I know lol.

You're MAP sensors are not bad there just 2 BAR Absolute MAP sensors. Once you hit 1bar guage they are at 5V and will not read any higher. This is why you do not see the drop on the AVCR.

Jeremy

The AVCR Map sensor isn't 2bar absolute.........

 

[Turbo Drifter]

The AVCR Map sensor isn't 2bar absolute.........

I'm well aware of that, I was referring to the JDM 2jz MAP sensor and the 1jz MAP. That’s why on the Logs it shows a drop or plateau wile the AVCR shows no drop.

Maybe I'm totally off base and have missed to much of this thread lately.

I believe I or some one else said back 40 plus pages ago to put the MAP on a dedicated vac line with no tees.

Jeremy

 

[tissimo]

The stock 2jz/1j map sensors I think work fine till ~ 16-18 psi. Maybe when they max out they give some weird reading and why you get the fall off.

Can you look at your logs and see the map Voltage from it? Or does it only display the pressure?

You had the stinger when you dynoed @ 24 psi? who tuned the car?

 

[IJ.]

I'm well aware of that, I was referring to the JDM 2jz MAP sensor and the 1jz MAP. That’s why on the Logs it shows a drop or plateau wile the AVCR shows no drop.

Maybe I'm totally off base and have missed to much of this thread lately.

I believe I or some one else said back 40 plus pages ago to put the MAP on a dedicated vac line with no tees.

Jeremy

Got ya now I read it backwards

I wonder how the Stinger translates it when the Map Sensor maxes out and give the weird reading Justin mentions?

This is another reason I'd like J to pressure test so we can get an idea of what actually happens in his boost range.

I run 1.5mm restrictors to the Map sensor as it evens out any spikes.

 

[bigaaron]

Problem Found!!! Stop the thread!

Look what's happening at 19psi! It's going to run way too rich and bog, causing the lack of boost. These maps are very critical to engine performance, the engine is going to run how the map looks, terrible.





Here's what my map I made for my car in Vegas looks like for comparison.
Keep in mind I made this while driving on the freeway, so it's not perfect, I needed to add resolution under vacuum to get rid of a little lean spot that happened when it was at cruise speed on the freeway. Notice there's no huge changes anywhere from one map point to another, except between 0psi and 14psi. Also, consider that I was only running 380cc stock injectors, so I needed to max them out under boost because I'm running a GT4082 turbo, which means all my map points under boost look more dramatic then yours would on a 3d map. You have much bigger injectors, so a huge change like your map has would probably add far more fuel then the engine needs.

 

[suprahero]

I see what's happening @ 19psi Aaron, but I"m never reaching that point. I have my boost cut set @ 19 psi and it's never once reached it. I couldn't tune it for 19psi since it never made it up that high in boost. We tried adjusting the AVC-R to make it run higher boost and it just wouldn't do it. It loses it and it drops down to 10psi. If it would make higher boost, wouldn't it just go rich on the dyno?

 

[suprahero]

I corrected my timing map and my fuel map to make them look more presentable. I took the peaks and valleys out made it look more like the one Aaron made. I took it for a drive and the same thing happens. At 6400rpm it went from 16psi to 9 psi, but the afr's never changed from 11.6..... Here is what the tune looks like now.

If someone can copy it and paste it on here, please do. I dont' know how to copy the picture like Aaron did.

 

[IJ.]

J: Open the Stinger software to display the map then press the "PrtScn" button on the keyboard open your MS Paint and "paste" save as a jpg file and you can post it.

 

[rakkasan]

J: Open the Stinger software to display the map then press the "PrtScn" button on the keyboard open your MS Paint and "paste" save as a jpg file and you can post it.

Like this Jay, LOL......

 

[IJ.]

See!

Even Mark can do it

 

[suprahero]

Don't you have to have a special software to do that though? I've tried it on my laptop after googling the instructions and it's never did it. I only wanted it done that way so everybody doesn't have to have the stinger to look at it.
I talked with my dyno guy today and he is going out of town until saturday. I am going to set up some dyno time for either saturday or monday. I'm going to video every pull, and record every datalog so that everyone can see what I'm seeing. I also want those of you that have told me in the past that you should be able to hear the boost leave when it loses six psi in one second to see that you can't hear it. I hope this will help find an answer to this problem that has caused me many many many sleepless nights.

 

[tekdeus]

Yes, if the AVCR shows no drop in boost, it probably is not dropping, just a sensor issue. My AVCR matches what my boost gauge reads. Dyno it and have them log boost through a separate gauge or sensor.

 

[suprahero]

Well, I know it's losing it Tex, because it's only making 430rwhp and it was making 510 @ the same horsepower last time. I'm going to the dyno next week or this saturday, and I'm going to video everything so I can give you more info on what's going on. Thanks

 

[bigaaron]

Shoulda just kept the 1jz in there like it was.

 

[suprahero]

Shoulda just kept the 1jz in there like it was.

Yeah, sometimes I think that too, but having driven the 1.5 for a month before blowing it up, it's definately worth it. I know this is going to be some stupid ass'd thing that I've overlooked, but until I find it, it'll continue pissing me off.
It still runs pretty good. It's making 430rwhp and it still pulls hard. I just want it perfect. Thanks.

 

[10secdream]

I know this is a long shot but is there anyone locally that you can borrow another stinger ems from? Perhaps the ecu is buggered somehow.

 

[IJ.]

^ done that already

 

[suprahero]

^ done that already

QFT........but thanks for the suggestion dreamer......:icon_bigg

 

[bigaaron]

I know this is a long shot but is there anyone locally that you can borrow another stinger ems from? Perhaps the ecu is buggered somehow.

I sold it to him, so it can't be the problem. Look for problems with all the items not purchased from me. :biglaugh:

The Stinger couldn't make the boost drop like it's doing unless the tune was so far off that the engine's power output dropped off. Put a heavier spring in the wastegate and disconnect the boost controller FTW!