About to throw in the towel!
 

Well I have had my car tuned a total of 3 times now by "professionals" the most recent one I left with 240whp a terrible stutter at WOT and 3 weeks later a blinking cel but no stutter at WOT it has now moved to the cruising rpms and makes my normal hiway driving a pain. The car drives like crap and and feels no more powerful than when I ran a stage 0 on 5psi. However Im running 12.5 psi.

I really dont know what else to do, I have played with the maps alittle and got the car driving slightly better but still making terrible power and horrible mpg (not my main concern but still...)

Any of you self or pro tuners out there have any tips lend me some advice before I end up ripping all of it out and sell my tC. I will list my setup below and can e-mail a copy of my map or data-log to anyone who would like to take a shot at helping. The blinking CEL worries me a bit.

MHI 20G @ 12.5psi
hks ssqv bov not recirc'd
cheap WG but it holds boost fine, turbo concepts i think is the brand
PWR liquid-to-air intercooler kit
550cc pnp injectors
Emanage ultimate w/ pressure sensor
innovate wideband
2.5 down pipe/s-pipe with QTP cutout on s-pipe
Gizzmo IBC boost controller
1 step colder plugs gapped at 35 (ive tried 2 step colder too and no improvement)

I think that covers it.

wish i could help ya out, I hate to hear stuff like this. I dont mess around with anything but the fic so far. not that i wouldnt want to but just havnt had the chance.

Umm...that's seems rather scary. 550cc @ 12.5 PSI on a 20G...man what kind of duty cycle is that? I can imagine it's HIGH. The Blinking CEL could mean that you are leaning out.

I would

A) Turn down the boost

or

B) Bump up the injector size.


I have ran as much as 11lbs on a 16G with 550cc's, but when I went to a 20G, I ran 750cc's on 11.5-12lbs. At that much boost on 750cc's I want to say my duty cycle was around 70-80%. You could be running out of fuel. More details on this please.

interesting im having the same problem with my car , in for updates

are u a 5 speed or auto

First I would change your gap on your plugs. .035 seems too big to me and I think most boosted scions are running .030 or smaller. I would try .028 to start out with and go up if the MPG is still low or go down if you are still stuttering. Next I agree with rhythm and that the boost level seems too high for 550cc injectors. I have a tdo6 20g and I run 10.5 psi and the FIC says I have a duty in the 90% range with an 11.5 AFR.

you guys say 12.5 is to high for 550's yet i know someone local at 16 psi on 550's... hes on the facebook boosted scions club and wrote that and me and mike (elevationtc) were like wtf bro hows that possible lol...

dude hes on stock exhaust and small turbo.. anything is possible..

First off email your map to mike@mtuned.net.. Ill look and see if theres anything funny.

Two. Like someone else said, check the gaps it could be spark blow-out. Blinking CEL is misfires!

Gap plugs to .27 also make sure plugs are not burnt up, take pics of the plugs if you could.

^
.027 - .030 should be a decent gap.

Yes check your plugs, check your injector duty cycles, check your compression (should have been done first before installing your turbo).

Yup i do a C-test before i tune anyone now. I include it in tuning cost. Both for me and customer good to know!

i say .027 which is a little tight but it deff elimintates blow out!

but like rob said .030 should be fine!

I checked the plugs they are at .030 and my duty cycle is about 85%. Most of the time I'm at 10psi. I'm at work now but ill email some stuff tomorrow. Thanks guys!

85% duty cycle at 10 psi ?, thats pretty high. How many miles do you have on your plugs do they look clean, if you are running very rich you could have fouled them out. Which would mess things up.

The plugs look pretty good, light grey, no fouling or black suit on any of them, no indication of spark knock either. I agree 85% duty cycle on 10psi is high, that explains my terrible mph, however i dont know why its taking 85% to keep me at good afr's.

Reading things like this, it only makes sense for people to buy kits from reputable companies. They have done all the R&D. Eliminates a lot of problems like this. Sorry for ya Rozz

True that, I forgot about that.

Rozz, what is your A/F at WOT?

Around 11.5-12. never goes over 12, when it stutters during cruising im getting too fat, when I pull fuel from that area then I lean out when entering boost.

Bro, you got to small of injectors. Either change them, lower the boost, or buy a Return Line Setup.

Food for thought, I'll sell you my 750cc injectors for $200 bucks + shipping. They are RC Engineering.

btw you happen to know your intake temps? got pics of your liquid to air intercooler?

Even on 10psi on a 20g i get those af/r's...550cc cant handle 10 psi on a 20g? I had it tuned up to 12.5 incase of overboost or for track. During normal driving im always at 10psi says the gizzmo. And before when Kenny tuned the car on the 20g i was around 65-70% at 10psi...something is happening elsewhere and causing my to use too much fuel I think. Unless my injectors are going out...anyway to test them?

Also how do you calibrate the TPS, i know mine got moved by my last tuner. Dont think it should have been.