nogar

Since this is my first post gonna get the noob in me out of my system now. Ive got an '87 TII w/ 45k original miles and mainly just upgraded w/ "bolt-on" parts. Started having problems w/ inconsistent boost last year right b4 i put the car into storage, and obviously the problem didnt solve itself while sittin there. Cant figure out why at random times my boost drops to around the stock 6.5-7 psi (i like to keep it around 10.5 or so) the only thing i can think of is the boost controller. right now im running a simple turn the dial controller w/ an old-fashion psi gauge. so am i right in assuming that i should just upgrade to a digital type controller, or am i just making an *** of myself?



(im not a total noob to the rotary though, had an '83 that i sold after buying this one)

jdm12a

im jus guessin here cuz im not sure but do u have a FCD and how high are you tryin to run it?

drunkin_idiot

ya you need an FCD(Fuel cut defenser) to bypass stock fuel cut which is 6.5psi on 86-88 and 8.5psi on 89-91. If you do thenwe can start discussing more probs.

KompressorLOgic

well i will assume you have the right fuel mods to run higher boost levels and what not...



you shouldnt need a digital controllor to raise it.....



try double checking all your hoses,



and then u might want to try taking apart the boost controllor you have ,and cleaning it or seeing if maybe the ball got stuck or something.....( i was running into problems my boost wouslnt raise even when cranking the controllor alot, i took it apart,re assembled it and it works fine, ball got stuck....))



if that doestn work then posibibly your turbo is damaged ( you would prolly know this, or hear bad noises ect,) or that controllor is messed up...

nogar

Yeah i got the FCD, and im only running 10.5 p.s.i. max when im getting the full boost i want. Im hoping its not the turbo itself, since it doesnt drop below the stock boost setting when its not running right, it does seem like the turbo lags more when it only hits the stock p.s.i. too. And when u guys mention fuel mods would that just be the FCD and some kind of fuel managment system, or am i missing out on more? When it was on the dyno a couple years back it ran 230 HP at the wheels so its not too heavily modifed, but should i go a little farther with the fuel system? Thanx for the input.

drunkin_idiot

230 at the wheels, then ur pushing the stock turbo. Fuel mods would include injectors, fuel pump, FPR ect. how would you make 230 with none of those?

KompressorLOgic

dangerously lean A/F would net that kind of power..... if you dont have upgraded injectors or somet ecu upgrade, id be very cautious as your walking a thin line.

nogar

Hmmm. The car actually always smells like its running rich and im hoping to get a Profec B soon but dont think ive got the cash for injectors since im kinda trying to build a house this year. The car has always run really strong for me and only problem i had since getting it 3 years ago was a rough idle. And after checking all the usuall stuff to fix it w/ no luck i gave up and actually just took it to Mazda dealer. After A LOT of convincing they took the car in and told me they just set the computer to factory specs and its run fine since except for the boost droping to stock p.s.i. randomly which started last year b4 i put the car into winter storage. Thanx again for the input.

nogar

Just wanna add that i was gonna just put in a "piggy-back" ECU but now w/ what im hearing should i go w/ stand-alone or can i actually find something decent that wont rape my bank account?

wankelTII

What kind of exhaust do you have? If the turbo is taking longer to spool and not holding boost much above stock levels, then make sure there arent any obstructions in the exhaust and make sure the turbo is sealed to the exhaust manifold properly with no leaks. What mods do you have?

check your vacuum lines, make sure they are all sealed really well and there are no leaks.



230whp is about the limit on stock injectors, because at 80%-85% duty cycle the injectors are capable of no more than about 260-270hp at the flywheel, and maybe not even that much. Anything much over 80% duty cycle on stock injectors can become inaccurate or unstable, so you are pushing the limits of the car for sure. You really need like 4 720cc injectors a wideband and an SAFC to pull back some fuel. For the stand alone to do you any good you will need a wideband and bigger injectors anyway, so go ahead and get those and an SAFC for the time being and save your money for a real engine management system later. Just my $0.02 All of this is cheaper than an engine. And if you dont have a fuel pump you might want one of those too.