R_PROWESS

iTrader: (3)

This is a healthy build -120 psi on all faces- (new housings and apex seals, like new irons) I'm just thinking the stock s4tII computer just can't handle it.

key factors
1. the block is "mild" pineapple street ported intake and exhaust
2. I used s5 housings with the different spark plug timing...
3. the rotors are s4 high compression

what the car is doing.. runs great above 1000 rpm. with the tps set at 1 ohm with the buttery fly cracked I back the throttle set screw out until the set screw isn't even touching the throttle linkage and at times it still runs at 1000 rpm for awhile. Eventually idle drops below that and somewhat tries to recover but ultimately dies. it's as if at 1000 rpm there is some sort of transition on the stock computer which it doesn't like to run under. I've checked and eliminated every conceivable vacuum leak.. i even reinstalled the BAC valve and it helped very little if at all.

I do have an aftermarket computer waiting (megasquirt), I just haven't installed it yet, decided to see if the engine would run at all before getting into that animal, which is a project on its own.

solutions?

Since I can't idle down to where I can set my timing it's hard to say where I am exactly... I put the timing where I could see it was set before, but I'm assuming with the housings being s5, I would need to either advance or retard it a few degrees anyway. ideas? other than idling low, it also take some fiddling with the injector cut switch to start it up. am I right to think I'm past the capabilities of my computer? also i set my base fuel pressure at 40 psi but i think stock is 38 or something..

NYsNumba1Man

iTrader: (1)

I'm sorry I cant help you on this one, but whats wrong with idling at 1k rpm?

Its not that big of a deal, our cars idle at 750rpm more or less...Its not as if you have a rough idle of like 2k+ or something.

Either way, Goodluck with getting this sorted out

R_PROWESS

iTrader: (3)

it's more like 1100 1200 where it seems to like to idle fine, the problem is in real world conditions at times the rpm will drop below that when taking off from a light. it will not recover and die most likely. at least mine doesn't seem to want to.. if i press the gas as its dieing at 800 rpm or whatever it backfires sometimes as if my timing is off, if i advance the timing it runs like **** if i retard the timing it runs like **** so lose lose situation

arghx

iTrader: (3)

Set the timing properly, using the factory timing marks.

satch

iTrader: (1)

Did you include the Variable Resistor in trying to set the proper idle?

R_PROWESS

iTrader: (3)

Set the timing properly, using the factory timing marks.

i did and that's where its set but im thinking the s5 housings require different timing also high compression from what im told should be retarded a couple degrees to run on the factory ecu fo ra boosted stock turbo car

the variable resistor is right in the middle, it doesn't change anything swing to swing for whatever reason



idk whats up, so nobody has had issues with exceeding the factory ecu at idle?

R_PROWESS

iTrader: (3)

i guess ill just wait a few weeks and install the megasquirt

satch

iTrader: (1)

Did you try making the adjustment with the initial set coupler jumpered?

R_PROWESS

iTrader: (3)

well i figured out what i think the culprit is.. i don't know what to do about it though..

the voltage drops below 1000rpm and it's changing my fuel pressure which in turn is changing my afr's

the FD alt i swapped during the build for whatever reason isn't charging below 1000 rpm or is charging significantly less. I'm seeing 14.47 volts anywhere above that point. i think the FC dual v belt pulley i have on it is too large diameter. i need something small to increase the rpms on the alternator.. anyone know of one? or is my reman alternator a POS

idk if a fuelpump rewire would somhow help me? i cant believe i havent done that yet, i have a bosch 044 ready to go in too...

g14novak

iTrader: (1)

Did you wire the alt up correctly?

And a bosch 044? You plan on wearing ear plugs while you drive this car? Thats a lot of fuel to be pushing for a stock turbo car. You'd be better off with a FD pump.

12AllWays

iTrader: (20)

^Haha. Earplugs, they arent that loud...lol

R_PROWESS

iTrader: (3)

you're assuming I'm keeping the turbo stock.. i also don't need ID1000's either lol

it'll be in tank, form what I hear it's not very loud especially not as loud as you're describing