Hi there. I ordered the stage 3 Nordic software from Nick. However, due to some undiagnosable hardware issue (something with the APC system), I can't get it to work! After spending a few hundred for my mechanic to check everything out, I'm discouraged it still isn't delivering the boost I want.
whats the problem are you not boosting correctly? if so check all your vac lines to make sure they are hooked up properly...should just be a plug and play with the ecu...
It hits about 8-9 psi and as the revs build it will creep to 10psi. I've disconnected the wastegate and she boosts like hell, but as soon as the BPC is in control the boost is lame
make sure all three lines are connected to the bpc correctly, and when they are unhook the battery for about 5 minutes reconnect and take it on the highway and do a few 4th gear wot pulls from about 3k-5k to do a ecu adaption, see if that solves the problem, then we will go back to the drawing bored, most likely it's something stupid wrong and not a hardware problem...trust me:cheesy:
what about the stiffer wastegate spring... would that have anything to do with it... and what i'd do is go through and replace all your vacuum lines with new **** anyways... it doesn't cost a lot and might just solve the problem... there could be a tiny *** whole... or something...
umm i was looking into getting a stg 3 for awhile and im pretty sure you have to get the new wastgate (stiffer 1-152 pound..i think) spring....i think this is so boost holds because the wastgates stays closed longer so you can build up and hit that 20psi
did you check with nick? you might want to give him a call and check on this...
I've already replaced the vac line to the BOV. Which other ones could cause problems? Just go around and replace everything I can find? I'll try disconnecting the battery for a few before I leave this morning and see if it changes. My last variable seems to be the wastegate. I don't fully understand the importance of the stiffer spring. It is capable of boosting 21psi without the wastegate, so perhaps that is the problem. Could it be adjusted wrong or something? It seems to me that it would at least boost to 15psi since thats what I was running before the chip
I've already replaced the vac line to the BOV. Which other ones could cause problems? Just go around and replace everything I can find? I'll try disconnecting the battery for a few before I leave this morning and see if it changes. My last variable seems to be the wastegate. I don't fully understand the importance of the stiffer spring. It is capable of boosting 21psi without the wastegate, so perhaps that is the problem. Could it be adjusted wrong or something? It seems to me that it would at least boost to 15psi since thats what I was running before the chip
A stiffer WG spring will kep the WG from blowing open under boost. I had to add a helper spring to mine just to keep it at 15 psi. They get weak over time.
As a test, wire closed the WGA arm so it can't move and take a run. If your boost is higher or hit fuel cuts, you know the WGA spring has gotten weak and is blowing open.
Is the fuse blown to the boost control valve? If it is you'll get basic boost Should be 12V on the centre pin of the connector.
I havn't needed a stronger spring on Stage 3 with a T25 turbo. Base boost anything over 7PSI will give boost spikes. Bigger turbos etc etc will need a stronger spring, but Stage 3 is tuned to respond to a certain basic boost when you whap open the throttle.
The wastegate is also a bit small when you add the 3" downpipe and you get boost creep at high revs no matter how wide open the (inadequate) wastegate is. Under-boosting should not be a problem
Huh, I haven't checked the fuse, I suppose that would make sense! :cheesy: If that doesn't fix it, should I swap wastegates from another NG900 we've got? It's got half the miles of mine and is newer, would it be something worth trying? But Like lms said, that's probably not the problem.
It sounds like you're running on base boost. If you take the time to pipe the turbo to the actuator and then run the car, you'll confirm that.
8~10PSI is a bit high and you'll need to remove a couple turns of preload. The base boost is probably high because you put the 3"DP on. It has that effect.
My money is on the fuse to the boost control valve being blown. There is more to come if it isn't that though.....
Is the correct fuse inside the car and labeled APC? It's a 7.5A fuse and it was not blown. Or is there a fuse under the hood? So your saying connect the WG directly to the turbo and that will show base boost?
It's fuse 13 on the drawing, but Fuse 24 'APC' 7.5A on the fuse list. Worth checking to see if you have 12V on the centre pin of the APC valve connector in any case.
Yes, if you connect the actuator to the turbo pressure tap, you'll get basic boost. The same effect happens if the power is missing from the APC valve or it's plug is disconnected.
I know you tried 2 APC valves, but you can thoroughly prove one of them by momentarily putting 12V between the centre pin on the valve and one of the outer pins. Be quick, like less than a second with the connection. The valve then latches. If you blow into the centre port, air should only come out of one of the outer ports.
If you them momentarily put 12V between the centre pin and the other outer pin on the valve, it'll latch the other way. Blowing into the centre port should then only allow air out of the opposite port.
If it doesn't change over or you get air blowing out of both ports, it's no good.
The fuse is ok. today I checked base boost, and it's correct (steady 7psi). I've been messing around with the BPCs i've got and it's possible they aren't 100%. One of the valves definitely is faulty, because even when I switch it, the air always comes out the Compressor port. The other one will swith over, but there seems to be a slight leak out of the port it's not supposed to be coming out of. It seems when I use this BPC that I gain about 2-3 psi over base boost. I read in an old saab repair manual that when there is no power on the BPC, when you blow in the R port, no air should come out. First when I tried this, air came out easily. Then, I switched it over a couple times, and then it blocked the air. When my mechanic looked at the car a few monthes ago, I had the two bpcs in the car and he checked them and said they were both OK. How can I check the connection from the ECU to the BPC? Also, could it be a problem with the box thats mounted on the sway bar?
It sounds like your 'good' valve isn't all that good. You might get a tiny amount of leakage out of the opposite port to the one it's switched to, but not a lot. You say it got better after a few toggles - sounds suspicious! So I'd try to borrow another valve from somewhere. A squirt of WD40 'might' free it, but I think the coils swell and thats what makes them stick and that can't be fixed. The seals in it could also be worn out.
It's unlikely the other connections are bad, although possible. Also possible for the transistors in the Trionic unit driving the valve to be bad. I checked mine with an LED volt tester to see the signals alternating. They're current sinking transistors.
The brass restrictor in the end port of the valve is important. It's not loose or been tampered with?
The part on your 'swaybar' is the pressure sensor. I think you'd be having fuelling problems if that was faulty, although I've never had a bad one to see.
**** that i blew a turbo this way... go with the bpc... you'll save yourself money in the long run...
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