Weird problem while trying to tune tonight:

[GotTurbos?]

mods:
HKS 1.2mm MHG
FMIC w/ hard pipes
GM 3'' MAF
MAF-T
Precision 550cc injectors
Walbro 255 fuel pump
CT-26 60-1
Full 3'' exhaust
HKS BOV
ARP head studs

So I just got the car a few days ago, got a boost leak fixed due to ghetto intercooler couplers, and had a friend (BigZavs) over to help me learn and tune this maft setup. At first we seemed to be progressing, working with the boost controller and maft to get things where we wanted them. After a few minutes of pulling over, tweaking, boosting, pulling over and repeat we had 1 very nice run 1st-3rd. I was pretty happy with it. We made a small adjustment and went back out for another try...

The best way I can describe it is to think of a perfectly running car, then take away the moving forward. It sounded like a possible boost leak, but it was still showing boost on the gauge, and we were still very slowly accelerating. I checked all the couplers and clamps and shook the crap out of them and nothing budged.

Ben (BigZavs) will be back home and on here tonight so hopefully he can offer a better description of whats going on.

Any ideas?

Thanks in advance,
Jon

 

[GotTurbos?]

Oh, and the car still runs fine under normal driving conditions.

 

[MDCmotorsports]

Sounds like a possible ripped coupler. One that won't open untill you see boost?

 

[GotTurbos?]

Sounds like a possible ripped coupler. One that won't open untill you see boost?

I thought about that too, but I really really tugged and inspected all of them. And, I'm still showing boost on the gauge, up to 14psi. That wouldn't happen if I blew a pipe.

 

[GotToyota?]

Jon, Ben and I told you the problem, it's a 7M.

Ninja edit: Indeed the problem is very weird. I'd say relocate the MAF like Ben said.

-Matt

 

[GotTurbos?]

That is not the problem though. Its something that will get done to the car, but it is not what is happening here.

 

[MDCmotorsports]

I thought about that too, but I really really tugged and inspected all of them. And, I'm still showing boost on the gauge, up to 14psi. That wouldn't happen if I blew a pipe.

Sure it would. I tore a couple a few years back. The car would make all sorts of nose and actually boost the full 10psi, but it wouldn't go any where and the AFR's were all over the place....

 

[GotTurbos?]

The car has been outside cooling down for a while, I'm going to go hardcore inspect everything in a little while, hopefully I find something.

 

[Datsrboi]

maybe bad sensor somewhere?

 

[GotTurbos?]

maybe bad sensor somewhere?

Such as?


Here is what has got me confused, feel free to correct me on anything you think might be a wrong assumption:

The only thing between the maf and throttle body is the BOV, I'm reading 14psi on the boost gauge, and the bov is acting as if it IS seeing all 14psi. Therefor I assume that the maf is seeing the same 14psi, as well as that boost making its way to the throttle body. So even if I had a boost leak somewhere, and the turbo was pumping out 30psi, the maf and the throttle body are still seeing 14psi and the car should still pull about normal.


I know for sure that there is not a leak between the maf and the throttle body, so what its reading is what the car is getting.

 

[thedave925]

You trying to use the maft's boost soleniod?

 

[Datsrboi]

I still do not know too much about supras but on my solara when I had it tuned caused allot of problems. I was getting full boost with no codes but my knock sensor was giving out and making my car time retarded on the dyno tune.

Either way I still want to see your car one day

 

[GotTurbos?]

You trying to use the maft's boost soleniod?

No I'm not.

I don't really know much about the maft setup, which is why I had Ben over to help out, hopefully he gets home soon and will chime in.

 

[GotTurbos?]

Don't worry guys, I found the problem: http://www.supramania.com/forums/member.php?u=834

 

[MA70Snowman]

:nono: i missed something.

 

[GotTurbos?]

Haha, It appears as though Ben turned the wrong knob on the maft, I didn't even look into it as I knew nothing about it. I read the manual a few times over, changed some settings, and its running much much better, tomorrow I'll go out and do a full test to make sure.

 

[Bigzavs]

i still stand by what i said, but considering i never tuned my MAF-T, i had almost no idea what the hell i was doing

 

[GotTurbos?]

Haha! My problem is that stupid badge on the timing belt cover.

 

[Bigzavs]

damn skippy, now go make yourself a masking tape badge like matt and i told you bizzatch

 

[CRE]

Laser printer label and scotch tape for longevity.

Don't feel bad on the MAF-T thing... plenty of us would have been a bit lost.