trialt

ok, so my car can boost to 15, BUT now it wont go past 3 psi smoothly. my car idles good and drives good until it sees boost, then it hesitates and sounds like an STi and drives like crap. it also sucks up a lot of gas and I cant figure out the problem. I changed spark plugs already and also checked other connections and everything else is fine.. any ideas? it drives fine as long as I dont use boost past about 3psi

95turbo gxe

iTrader: (25)

It sounds like mis fire to me. Check your coils they may not misfire intill you put the car under a load!

Matt93SE

iTrader: (44)

my money is on a boost leak after the MAF.

maxmaxima91

im with him on that one

trialt

hmm might be the coils like you said.. theres no boost leak after the maf im sure because i just checked it about 3 times because thats what I thought it was.. and it only happens under boost. I had a maf leak before and its worse than that.. btw how do I check the coils?

update: ive checked out all the hoses/fittings yet again and I also made sure the maf was clean.

ill also add a precise description and maybe someone had experienced it before?:
I start the car up and it idles like normal, no changes..if i drive it normal..(light foot, not letting the boost gauge go past 0psi) then it runs fine.. once it sees at least 2psi of boost it feels like the engine is not firing in a cylinder or 2.. and my gas gauge drastically goes down when I step on it... also if i floor it and try to boost my car actually goes slower than when i drive normally and it sounds like a subaru. ive already changed the plugs to ngk copper 2 step colder and ive checked for boost or vacuum line leaks. only other thing I can think of is maybe the coils like 95turbo said? cant think of anything else..

scrhale

Sounds like the car is detecting that it is too lean (when it isn't) and therefore dumping a lot of fuel and causing misfires due to flooding. That is just my opinion. Maybe check O2 sensors??

trialt

ahh a possibility.. which O2 is responsible for the air/fuel mix?

MaxInProgress

iTrader: (2)

eeerrrr.......are you boosting without a wideband? If you are then STOP NOW!!!!!!!!!! Get a wideband and see what your a/f is when this happens. You spent all that money on a turbo setup but you dont buy one of the most important things to make sure your not gonna blow your engine? To me it sounds like your running too rich. Are you having a startup problem when you frist crank the car? What size injectors do you have? What kind of fuel setup? Did you gap your spark plugs correctly?

MaxInProgress

iTrader: (2)

Also im surprised no one mentioned this yet. Are you running a jwt ecu or a stock ecu? If your runing a stock ecu and your boosting 15lbs your engine wont last 1 week. After 10 lbs you need to start to advance timing which im sure your not doing. DO NOT BOOST MORE THEN 10LBS ON STOCK ECU!!!!!! I wouldnt be surprised if you blew something up already.

Alex_V

Advancing timing? Dont you mean retard timing?

~Alex

ewuzh

iTrader: (20)

I thought the O2 sensors aren't used for feedback during open loop (WOT) operation. It's all ECU maps and MAF readings from there.

How did your plugs look when you changed them? Are they fouled? Is there a strong smell of fuel? Any smoke out the exhaust when you boost? Were the injectors ever replaced? Could be a leaking injector O-ring, especially with running over 100psi boosted fuel pressure with your FMU.

trialt

i have checked out a lot of things.. and i have kind of narrowed it down to injectors or coils. I highly think its a coil though.. but its an on/off problem with the coil.. well ill see when my new injectors and coils come in this week. and I guess I will have to invest in an emanage and a wideband. hmm any other possibilities? also, other than detonation are there any other needs for the timing retard? im assuming that a jwt or emanage are the only ways to adjust timing.. anyone have one for sale?

UNDEFINED76

u should get ur car tuned...thats probably why its doing that....go with greddy emanage ultimate...thats what im going with...