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not sure where to start

1K views 17 replies 6 participants last post by  project13 
#1 ·
i just purchased a 97 900 set talledaga. it has been modified but since i didnt do it i have no idea whats in it or how to find out. here is what i know:

1) it must have a BOV based on the whoosh sound off throttle
2) there is pillar boost gauge. boost never goes over 15 psi however.
3) i had in to dealer last week for poor driveablity and CEL. they said with mods installed i will always get CELs and they pulled like 4 codes out of from the mods "tricking" the ecu. they found a vac leak and replaced a $5 hose and it seems to drive better but with less boost.

i have no idea if ecu is stock or not.

i would like to ensure the car and mods are properly tuned. is this a DIY project or are there shops that will "tune" for you?

thanks.
 
#2 · (Edited)
Not true, t5 works great with bigger exhaust, bigger ic's and many other mods like bov's and the like. I would think its a stock ecu if the boost is not above 15psi. Most tuned ecu's of the stage 3 level are around 20psi. Check for boost leaks, all your ic boost hoses and clamps. The bpc may be sticking, try cleaning it with wd-40 and blow out with compressed air. You can pull the ecu below the glove compartment, passenger side and see if its labled as sqr, nordic, jsp, most tuned ecu's have the markings on the case!

I would first change the spark plugs, put in the ngk bcpr7es-11. These plugs work best on our cars and gap the plugs to .35". Use dielectric grease on the spark plug boots too. Vacuum leaks might throw a cel and so would a misfire from bad plugs. Do a full tune up with new fuel filter and the plugs especially.

You can clear the cel codes by disconnecting the negative battery terminal for 10 minutes or find the ecu fuse and pull it. If the cel comes back on there is a problem and you need to find out what the codes are and fix them. It could be o2 sensor, map sensor, mis-fire, but I bet if you tune it up and replace and inspect all the vacuum and boost lines, you will be just fine!!!

I have a modded ng900 with 400bhp, monster ic, 2.5" delivery pipe, bov, 60# seimans fuel injectors, ported and polished head, 3" full exhaust, water/methonal injection and a 3" cold air intake and I never get any cel's !!! I also expect to pass emmissions here in a few months as my tuner Jak Stoll just passed his car with 60lb injectors and 380whp! Most shops hate modded cars and say things to discourage you, do not let them get you down!!! Good Luck,
John
 
#4 · (Edited)
Make sure you use the ngk bcpr7es-11, that is very important and gap them to .35". Run the best gas you can get!!! Re-set your ecu and do some adaptation pulls. You have to pull the negative battery cable to do this or find the right fuse. Make sure you have the radio code before you disconnect the battery! You want to do these with good airflow, so do them in 4th gear from 2500rpm to 4200rpm. You need to do at least 3 pulls this way and keep it wide open throttle for the pull. Let it cool off for a minute or so between each adaptation pull.

Re-cap, tune up with new plugs, new fuel filter, check the check-valve from valve cover to throttle body and blow out the bpc with strong compressed air from a air compressor. Re-set the ecu and do some adaptation pulls. Check all vacuum and boost lines for cracks and replace them if they are. Check base boost, make sure its set to 5.5-6psi. You can unplug your electrical connection to your bpc and run a pressure gage from a t in the vacuum line from the bpv to throttle body and run it under the hood and into the cabin. Then you go wot in third gear and read your boost psi, this is base boost, it should be around 5.5-6psi or mid yellow on the dash gage.

If no boost gage it should be mid yellow on the apc gage on the dash, but that is not very accurate. If its low, you need to adjust the waste gate actuator arm by shortening it a little maybe 2 turns and check base boost again on the road in third gear. Adjust until its at least 5.5psi. I would do this after all the other things have been done as a final check!!! Good Luck,

John
 
#6 ·
wow mike, that is a great offer. there are so many questions i have, and problems i am experiencing.... we will be in antigo for easter this friday thru monday and planned to take the saab. if you have an hour to spend tuning i could cruise over to wausau one of those days. today i experienced my first fuel cutoff at full boost........ i will always wear my seatbelt form now on. anyway, not sure how to address that. let me know. jim
 
#8 ·
As John said, without software (i.e a tuned ECU) you're limited to how much boost you can run. Dial the boost back a bit and keep it to 15lbs and you shouldn't have that issue.

Or, even better send your ECU to Jak Stoll or Genuine Saab and have them put a tune on it. I'm sending out my 2nd ECU to Jak tomorrow afternoon and should have it back and installed in the car this weekend along with a 3" exhaust systen from the turbo back (which is already on the car).

Mike
 
#13 ·
ok i found it and dialed it back a notch. will tryand see if that does it. whats the point of a manual boost control if you cant go over the stock ecu 15 psi anyway w/o fuel cut? there are some other HKS mods under the hood.........not sure exactly what i have, just some other stuff labeled hks.

i wish i knew what is was and how to tune this thing right so i get most bang for my mods. but i am not sure how to do it and adapt the ecu and all that. after i i dialed boost back and have no more fuel cut (so far) but the "pull" of the car is noticeably slower. plus i am only getting 10 psi of boost in 2nd gear when i floor it it wont give me any more and kind of hovers there. i never had the fuel cut problem and had awesome pull unitl dealer replaced a vacuum hose they said was bad?? but i did have driveability issues because of that hose such as jerking and hesitation....

bigsky are interested in doing some side tuning for cash next time in am in antigo?
 
#14 ·
ok, i may have posted too soon. i put in new plugs tonight and was doing some test pulls. i dialed back boost 2 full notches on my mbc. i am still getting what i originally called "fuel cut" mostly in 3rd gear when i go WOT. the car kind of bucks real hard when i get to 4500 or so rpms or 15 psi on the gauge. it only really happens when i go WOT crusing already in 3rd from about 2000 rpms. it wasnt doing it when i start from still and shift WOT thru to 3rd hitting it at a higher rpm. could this be clutch slippage. its almost like a hard buck you might get if you upshifted too early and floored it. i am afraid to pass anyone unitl i get this resolved..
 
#15 ·
Sounds like you are still hitting boost cut in third gear. When you start in first and wind through the gears, the ic gets more heat-soaked and you will not spike as high on the boost and hit fuel cut. Just driving along with good airflow and then you go wot in third you will get a higher boost spike and hit fuel cut.

MBC's allow you to get more boost in first and second gear and really do not do much in third and up gears if a car is running well anyway. They really only allow quicker spool-up in the lower gears where the ecu limits boost and or torque for traction reasons;) It may allow slightly faster spool in the upper gears, but the max boost will not be much different than a well tuned stock car with good gas and a well adapted ecu...

The only way to get the real gains out of the car in all the gears is to get a tuned ecu and elliminate the fuel cut and run 20psi with larger intake, exhaust and ic:cool:

John
 
#16 ·
ok. i think i know what has transpired. the former owner had installed and mbc, bov, sport exhaust and some other mods like k&n AF and maybe a modifed intake lableled hks? anyway, the ecu is stock so he disconnected the vac hose to the Map sensor to trick the ecu so that he did not get fuel cut at 15psi, in fact i was pulling 20-22psi with no problem. however this caused the car to run poorly with hestitations and stuttering. hence my visit to dealer where they quickly diagnosed a vac leak to map sensor then charged me $200 to replace a $5 vac hose. now of course the map sensor is back online so that explains why the car runs better but i now have fuel cut at 15psi. so, where do i start now that i think i know the history? i thought the answer was to order a tuned ecu from nordic but when i called the guy said i had to remove my mbc and go back to stock using apc, which i dont want to do. any thoughts on an easy fix to relieve fuel cut? a guy at kcsaab said you can put a volt clmap on the MAP so it doesnt go over 3.45volts which triggers fuel cut?
 
#17 ·
jimzigg said:
ok. i think i know what has transpired. the former owner had installed and mbc, bov, sport exhaust and some other mods like k&n AF and maybe a modifed intake lableled hks? anyway, the ecu is stock so he disconnected the vac hose to the Map sensor to trick the ecu so that he did not get fuel cut at 15psi, in fact i was pulling 20-22psi with no problem. however this caused the car to run poorly with hestitations and stuttering. hence my visit to dealer where they quickly diagnosed a vac leak to map sensor then charged me $200 to replace a $5 vac hose. now of course the map sensor is back online so that explains why the car runs better but i now have fuel cut at 15psi. so, where do i start now that i think i know the history? i thought the answer was to order a tuned ecu from nordic but when i called the guy said i had to remove my mbc and go back to stock using apc, which i dont want to do. any thoughts on an easy fix to relieve fuel cut? a guy at kcsaab said you can put a volt clmap on the MAP so it doesnt go over 3.45volts which triggers fuel cut?
adjust the manual boost controller by turning the nob on it, then do a test drive and floor it and see if the max psi lowers. repeat this untill you get a max psi of 15 and no longer get fuel cut off(make sure your in sport mode if its an automatic)
 
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