jasono718

iTrader: (-1)

i installed a diy turbo kit and have been having problems with boost... dont reach full boost until 6k rpms, 10psi ... also, sometimes when i am wot the car seems to choke.. like a hesitation..after 4k rpms.. sometimes it does it sometimes it doesnt..
i have a 16g evo 3 turbo, 1.8l injectors, 255 fuel pump, fm single exhaust and off road pipe, 2.5" dp, fmu, ngk plugs, huge xs intercooler, customer 2" piping... megan manifold
cant really figure it out.. taken it to a few shops.. no results yet..
please help..

magnamx-5

iTrader: (7)

at 10 psi the evo 3 flows alot of air man you might try taking the boost back. My small 16g made 200 dynojet rwhp at 8-9 psi so your evo3 migth just be pushing abit to much air intothe system causing you to be to lean, what rate of rise are you using on the fmu. The 255 upped my idle pressure about 10psi this will richen you up to on low end making it slugish. I had a similiar problem with some 460's but i doubt the 1.8's are flooding your motor like mine ws most likely you aer lean up top and very rich down low.
tweak the afm, read braineacks thread and check for leaks ont he exhaust manifold as well this will delay spool and full boost.

samnavy

iTrader: (7)

It would seem that you're definitely having a fueling issue.
It's your first post, how about telling us every turbo part you're using. I see no mention of a fuel or timing control. I assume at a minimum you've got an AFPR and Bipes??? Whatcha got?

But to begin:
YOU MUST INSTALL A FUEL PRESSURE GAUGE INLINE WITH THE RAIL SO YOU CAN SEE WHAT FUEL PRESSURE YOU'RE GETTING IN RELATION TO BOOST RISE.
If you do have a gauge, what are you getting for IDLEpsi and ~0psi?

I would bet that you haven't done anything to tune it. You've taken it to a couple shops... what did they do? If it was Pep Boys, then they probably made it worse. If it was a speedshop, then they should have known pretty quick and suggested you get it on the dyno and have it tuned.

If there are no exhaust leaks, no vaccum leaks, and your fuel pump is good, then it's just a matter of putting it on a Dyno with WB02 and having a pro tune it.

Other problems might be a broken Wastegate Actuator. Maybe a blocked fuel filter... did you install a new one with the kit? Contributing might be a blocked cat... what did it look like inside when you put the DP on?

I would try this as a test. Unhook the wastegate arm and go run the **** out of it for a few miles with no boost? Do you still have any problems? If so, we can certainly nail it down to a fuel issue.

You should also verify that you've got no IC leakage. There's a nifty little DIY test in one of the sticky's where you can make a pressure cap and check for leaks.

Next... take some pictures and fill out your vbGarage so we can SEE what you're working with.

AND WELCOME!!!

magnamx-5

iTrader: (7)

SOTP tuning is easy to and could get him past there hurbles esp since he is still within the correction range of the stock ecu.

Ben

iTrader: (33)

Sam & Magna both nailed this one imho. Sounds tuning related. I'd wager you're running real rich until you run out of injector. Do the tests Sam recommended and bring your boost down.

adbradley

iTrader: (2)

I am so glad to be in the presence of true experts!

magnamx-5

iTrader: (7)

yeah ben can be abit aww inspiring at times what with his knowledge of cats and bangup theorys j/k

m2cupcar

iTrader: (5)

af gauge is nice for situations like this

adbradley

iTrader: (2)

AF guages are to cheep to not have one!

jasono718

iTrader: (-1)

ill get an air flow gauge in there this week...
ive been to drt and rpm in nyc...
theres no cat in the car i have the fm off road pipe...
as soon as i get the car back from paint ill send pics of the set up and send a complete listing of parts...
you guys are great thanks for the help!!

samnavy

iTrader: (7)

Jason, AF is not airflow... it's Air/Fuel. That's the WB02 (WideBand Oxygen) thing we're talking about. It's a device that utilizes an Oxygen Sensor mounted in your exhaust flow, either through an existing bung or on a sniffer sensor inserted in the tailpipe. It measures the exhaust gas and can tell whether you're running rich or lean (ie, too much, or not enough fuel). I'd recommend not driving it at all until you can take it to a dyno or have someone with a portable WB come and check you out. Like others have said, it sounds like you're running extremely lean in the upper RPM's... Lean+Boost+WOT=BLOWN MOTOR!!! This is not a scare tactic... you're seriously in danger of hurting your motor badly. If you must drive it, I earnestly suggest you disconnect the wastegate arm and run it WITHOUT boost until you can get your fueling issue solved.
But you won't get anywhere without a fuel pressure gauge.

INSTALLING A FUEL PRESSURE GAUGE IS YOUR NEXT STEP!!!! Make sure it'll read up to about 130psi.

There are two very popular WB02 systems you can install in your car permanently. All Dyno's will have them to use (that's how they tune), but to get one in your car, we recommend the Innovate LC-1 or LM-1, or the AEM. The AEM is sold through one of the forum regulars here for a great price: https://www.miataturbo.net/forums/showthread.php?t=5882
The Innovate products http://www.innovatemotorsports.com/index.html are also great buys and I believe the cheapest place to get them is still eBay. When I do purchase one, I'll probably go with this http://www.innovatemotorsports.com/x...664a1dcc8585f7 Yes, it's considerably more, but I'll be able to use it on every car I ever own, and never need a dyno. The basic LC-1 with a gauge that's comparable to the AEM can be had for under $300.

Also, I just checked out the RPM website and see no mention or photos anywhere on their website about having a Dyno... they seem pretty legit, but a speedshop without a dyno is useless to you.http://rpmnyc.com/newsite/index2.htm
The DRT racing website http://www.drtracing.com/drt.htm would not fully load for me, but it does say on their "services" page that they've got a Dynojet. Both places seem like strictly Honda stuff, so they might have looked at your budget DIY Miata and given you a polite "****-off".

jasono718

iTrader: (-1)

drt has a dyno but i dont like those guys...charge waaaayyy to much $$$
rpm is great but they dont have a dyno until they move to a new shop....
ill get the a/f gauge tomorrow and install in on friday..
im going to disconnect the wastegate arm to see if it is a fuel problem..
thx

jasono718

iTrader: (-1)

what type of engine management is best for the miata? megsquirt, link, hydra?? any others...

Braineack

iTrader: (62)

hesitation you are feeling is a lean tip-in, very common problem with a fairly easy cure.

magnamx-5

iTrader: (7)

af=air flow first time i ever heard that. Nice joke jason we always apreciate a comedian. To answer your question of Engine managment any of the systems Mega Squirt, hydra, link well serve you well past the point in wich your engine wont be able to hold it all together so you cant go wrong there. The main issue is the FM stuff is priceir than the Megasquirt but the megasquirt is more versatile and labor intensive on the setup. I believe newbsauce is in staton island and olderguy is in New jersey maybe if they arent to far from you they can recomend a place or help you on the phone whatever Older guy is very cool dont know about newbsauce though good luck.

jasono718

iTrader: (-1)

looking to swap pumps for a 190 lph hp pump.. the install kit is for a 1994-1997
has anyone tried to use the install kit for an earlier year miata???

Braineack

iTrader: (62)

It's the same thing...read my PROJECTS link for Sam's install instructions.

jasono718

iTrader: (-1)

you really know your stuff...
thanks for the help

Fireindc

iTrader: (13)

Oh yeah, these guys are the ****.