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Hello everyone,
Before you start to read this, please know that THIS IS LONG! Don't get angry with me, i really need some advice! ;)
Ok, where to begin...
1990 9000 turbo, many mods, new engine...
Symptoms:
-Fluctuating MAX boost levels between 9 and 15 psi throughout the week. Sometimes up at 15 psi all day, but it never makes it past two days though. Performance seems to go up and down while driving the car.
-frequent knocking, and boost pressure reduction as a result. AT LEAST one knock in every three days of driving the car on average. More than i remember in the past for sure.
-took car to a DYNO shop. A mustang Load bearing dyno. I scored a WHOPPING 132.7 HP at 5500 RPMS, and 166 MAX torque at 3750 RPMS... that's worse than stock...
check out my modifcations on my website if you are unfamiliar with them... i should get well over 200 Hp in my own opinion...
http://www.geocities.com/griffin800/index.html
ANYWAYS....
my first guess at the low HP scores... the BPC!
I cleaned the BPC after the run, and decided it was spent, and not cleanable... besides if it were replaced with a brand new one, then i could move on to diagnosing other problems, and rule the BOC out... so i shelled out $200 at eeuroparts.com, and bought a brand spankin new BPC.
It arrived today, and i installed it in the car... it had the same PART NUMBER...however i get the feeling by comparing them that the new one is designed for a later model 9000... because they used the same BPC from 1990-1998... they must have changed it a little? or did they leave it the same?
I was hoping someone could clarify that for me... that they are EXACTLY the same, and i should just trust that the new one is going to work perfectly on my car.
Anyways... i plug it in, and get movin... and i get 12 psi MAX CONSTANTLY. Never more, never less for max psi... When i swapped it back with my old one, i would get up to 15 psi MAX again, but with the fluctuating...
i don't understand that at all! How can the new one perform *worse* than my 14 year old one? Is the older one designed specifically for my car?
I tested them by charging the coils both ways, one way at a time, and blowing into the wastegate hose connection, to make sure a seal was present...
the NEW one did NOT have a perfect seal of the wastegate... which means it can be opening the wastegate some during boost!!!
Does it need TIME to break in?????????
Or should i now re-adjust my wastegate to coincide with the brand new BPC operation NO MATTER WHAT? This is what i'm thinking...
when i disconnect the W hose completely, with either BPC, i get 20 PSI max, easily.
So, that's a little challange for some of you saabnuts out there! Have fun....
PROBLEM NUMBER TWO...
So, back to that crappy DYNO run... by looking at it, and knowing that all the major mechanical parts on my engine have been thouroughly inspected and almost EVERYTHING replaced... i can assume two things:
poor fuel delivery, and poor boost levels.
This was the last of three runs. The first run i scored a 120, the second a 127, and the 3rd a 132....
The first run i was getting under 10 psi max boost, the second about 12, and the third maxed out at 15, and then taperd off to 10...
they were all within 15 minutes of each other... This is the kind of fluctuation i was taking about earlier. (PRE BPC cleaning and replacement).
Anyways, i thought that the fluctuation was caused by the BPC, and i guess it IS, but still the BOC isn't the ONLY reason for low boost levels when the W hose is still connected...
When i got home the other day, i checked to make sure my Hyperboost adjustable bypass valve was properly adjusted... and it wasn't! There was almost no preload on the spring, so it was possibly bleeding all the pressure off over 15 PSI... i adjusted it accoring to the guidelines of another saab owner who uses the same BOV, and now with the W hose disconnected as a "test" for the adjustments, boost will hold at a constant 20 psi... which is good enough for me, so i know the valve isn't bleeding it off anymore. It's not all of the way closed either, because the WHOOSHE can still be heard when the throttle is released, at ANY psi level... so BOV fine...HORRAY
...anyways, by looking at the dynograph, you can pretty much assume that along with the low boost, there is some fuel delivery problems going on too.
The injectors are fine, DI appears to be fine (i have a spare just in case), and the fuel pump hasn't had any problems yet. The FPR wasn't connected for over 3,000 miles, and it's possibly bad, i'm hoping to replace it soon with a 3.0 BAR unit...
... the WILD CARD in the hand of fuel injection appears to be my LH 2.4 ECU.
I've had problems with the computers in the past... meaning a few of them mysteriously stopped working, like 2 PAIRS of them, and i had a couple odd check engine light codes, (60001 rom failure!) that are gone now with the replacing of the ecu itself... however... the custom ECU CHIP from abbott racing has been moved around from box to box a few times, and it's possible that it's messed up!!!
It's ALSO possible that the chip was somehow dammaged by the vacuum lines being hooked up wrong on the car for so long, and the fuel system being rendered almost useless...... for those of you who remember THAT mess...
...i've reset it a few times, and there is no real effect. I guess my ECU only has 2 MAPS to choose from anyways: High octane and LOW octane... it doesnt really "learn" anything like a trionic, according to JAK...
............. SOOOOOO...........today after i replaced the BPC with no real results... i decided to take the PLUNGE... and narrow the problem down further by replacing the performance chips with the stock chips... this would ENSURE that a working chip would be in the car... and with working chips, stock t25 and a good BPC, i SHOULD get AT LEAST 165 hp... right?
First i did the ECU chip... upon replacing the computer in the car, and turning the key to ON, i got a steady, pulsing check engine light...
...however it WENT AWAY when i started the car... very odd...
I thought the stock chip might be fried, so rather than drive the car anywhere, i could just try replacing it with ANOTHER stock chip i had of the same kind... just to make sure that the check engine light wasn't a result of a bad stock chip.
Sure enough, upon replacing the first stock chip with the second one, the flashing check engine light remained ON, but went away again with the starting of the car...
I decided to drive it around anyways... and i could totally tell the difference in performance right away, it was a noticeably SMOOTHER ride with the stock ECU chip than with my abbott chip... very weird indeed...
Boost levels were still only at 11-12 psi MAX with the stock ECU chip and the BRAND NEW BPC... obviously something still amiss...
So after a short spin, i went back home to replace the abbott DI/APC chip with the stock ones i had... and i opened an OLD can of worms at this point....
the DI/APC computer from my car got fried (long story) and was replaced by a box from a saab junk part dealer, with a box of the *SAME PART NUMBER*...
...however the new circuit board on the replacement box was TOTALLY DIFFERENT than the original one in my car! I assume they would be different in performance somehow??? maybe not though...
anyways... i bought 2 replacement boxes, and the replacements are the same type of board, i can't seem to find a replacement board of the SAME ORIGINAL type for my car? Check the link below to see photos of the three di/apc boxes i have... and compare them. Someone please help me figure out:
WHY ARE THEY DIFFERENT AND WHAT DIFFERENCES IN PERFORMANCE THEY HAVE!
moving on... two of the DI/apc boxes WILL NOT WORK... period. The car will not start with them installed... regardless of what chip is installed in them. The only working box is NOT of the same exact cuircuit board type that originally came in my car. very odd again...
...so... upon testing all possible configurations of the DI/APC computers and chips, i finally put the only known working box BACK in with the STOCK chip installed in it... and took it for another spin.
NO CHECK ENGINE LIGHT AT ALL...and...
The car feels BETTER with the stock chips, even though boost levels never go above 12 psi, it feels as if the car can do MORE with LESS boost... and if i could tune the pressure up to 18-20 psi right now with the current performance levels of the stock chips... it feels as if i'd be going very fast!
SO... what happened to my chips? is my car so radically altered now that i need to have JAK custom map me some chips?
Why are the APC circuits different?
Why does the OLD BPC achieve higher boost levels than the BRAND NEW one?
Will adjusting my wastegate NOW with this stock chip, new BPC configuration i have give me back my performance that i one had when the car was COMPLETELY STOCK?
Will i ever break 200 hp at the wheels?
why did i spend so much money on a P.O.S. in the first place?
;p
thank you for reading this... perhaps it's a post for the performance board!
-gavin
posted by 69.169.238...
Please click here to see the differences between the DI boxes I have
, Fri, 20 Aug 2004 21:53:16
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