SaabCentral Forums banner
1 - 20 of 20 Posts

·
Registered
Joined
·
247 Posts
Discussion Starter · #1 ·
I got my rear o2 sensor bung moved forward on my JSP downpipe because I was getting an inactivity code for the rear sensor even after replacing both o2 sensors, repairing junction 36, and diagnosing via tech II. I reset the ECU to get the original CEL off and was driving around and I gave it some gas and hit fuel cut. I took it out later and in second gear, I gave it gas and it hit fuel cut.

Is this most likely just the ECU adapting? Thanks in advance!
 

·
Registered
Joined
·
12,355 Posts
You should never get fuel cut in first or second, if the electronics are stock. It sounds like the BPC needs to be cleaned. You're probably boosting halfway into the red in other gears, right?... Ron
 

·
Registered
Joined
·
247 Posts
Discussion Starter · #4 ·
It was about 50 degrees last night. I have never hit boost cut before with this ECU (JZW tune) even after reseting it in the past which was why I am asking, and I have a hard time believing that something like the BPC would spontaneously go bad. (the car has 35,000 miles on it)
 

·
Registered
Joined
·
12,355 Posts
They normally don't go bad, they just get dirty. Do you happen to have a free-flow intake by any chance? If you do, go to eEuroparts and look at the BPV description. They won't warranty the BPV ($277.00) if your running a free-flow intake because they get dirty quickly. You can clean them with carb cleaner in about 10 minutes. Anything other than that and you need to talk to John Z... Ron
 

·
Registered
Joined
·
247 Posts
Discussion Starter · #6 ·
Thanks Ron, I appreciate your help. I went out for some adaptation runs on the highway (my car is an automatic) and the car pulled very hard when I did 4th gear pulls and I could not replicate fuel cut no matter how hard I tried.

The CEL is still off, so I am remaining optimistic that this o2 inactivity code is gone for good. :)
 

·
Registered
Joined
·
2,639 Posts
I'm not a fan of the adaption runs, where you go WOT from 1500 to 3000 rpms, then mash on the brakes while still WOT. Something about that procedure doesn't seem right... Ron
Why do you mash on the brakes during WOT..? Sounds like you're trying to check your base boost, not doing adaptation runs. That's probably why it seems wrong.
 

·
Registered
Joined
·
247 Posts
Discussion Starter · #9 ·
I'm not a fan of the adaption runs, where you go WOT from 1500 to 3000 rpms, then mash on the brakes while still WOT. Something about that procedure doesn't seem right... Ron
I never stand on the brakes doing adaptation runs, I just roll into it when the tranny locks into 4th and pull as hard as possible from 2k to 3.5k which seems to work for me. It is harder to adapt with an automatic in my opinion but no braking is involved.

I'm guessing you are thinking of checking base boost. ;)
 

·
Registered
Joined
·
2,490 Posts
i though you check base boost by bypassing the BPC directly to the wastegate actuator
 

·
Registered
Joined
·
247 Posts
Discussion Starter · #12 ·
I thought that you were supposed to check base boost once in a while. It just seems like an odd way to do it... Ron
I know my base boost is correct, 8 psi on the button. I did not go out to check base boost since I know it hasn't changed, I just went out to do some adaptation runs which consisted of WOT runs in 4th gear from 2,000 rpm to 3500 rpm a couple of times.

The standing on brakes to check base boost technique comes from the technical section of GS.

i though you check base boost by bypassing the BPC directly to the wastegate actuator
You are right, I wasn't out to check base boost since I know it was properly set. I only did WOT runs to let the ECU adapt on the highway.
 

·
Registered
Joined
·
4,857 Posts
I got my rear o2 sensor bung moved forward on my JSP downpipe because I was getting an inactivity code for the rear sensor even after replacing both o2 sensors, repairing junction 36, and diagnosing via tech II. I reset the ECU to get the original CEL off and was driving around and I gave it some gas and hit fuel cut. I took it out later and in second gear, I gave it gas and it hit fuel cut.

Is this most likely just the ECU adapting? Thanks in advance!
Its not fuel cut, it is turned off in your file, my guess would be a weak fuel pump or your plug gap is too large and you are getting quench. Try a set of new plugs and gap them to .034" and you may want to read your plugs or have your fuel pressure checked. Sounds like you may have a fuel pump that is starting to go.

Glad you got the rear 02 problem figured out :)

John
 

·
Registered
Joined
·
247 Posts
Discussion Starter · #14 ·
Its not fuel cut, it is turned off in your file, my guess would be a weak fuel pump or your plug gap is too large and you are getting quench. Try a set of new plugs and gap them to .034" and you may want to read your plugs or have your fuel pressure checked. Sounds like you may have a fuel pump that is starting to go.

Glad you got the rear 02 problem figured out :)

John
Definately not the fuel pump, I can gaurantee you that. It is a practically brand new Walbro. I gapped the plugs to .39 factory spec before I put them in, and the plugs I took out looked perfect; just a bit of white on the tip from burnoff and just the lightest black tinge on the base. I took it for another couple drives later yesterday and did not get any fuel cut whatsoever so I think it is good to go!

Thanks John.
 

·
Registered
Joined
·
4,857 Posts
.039" is a little high for your power level, .034 would be closer to what you need and remember the boost pulls the gap apart, so they need to be replaced every so often.

I learned the hard way that just because a part is new does not mean its working fine. I am on #4 fuel pumps that have been bad right out of the box. I do not trust the walbro inserts at all and there have been a lot of people with pump failues this year and two that only lasted a few months.

My local indy shops have stopped replacing fuel pumps with inserts, the failure rate is just way too high and if you look at eeuro, they no longer sell the insert because of the failure rate.

Not saying your pump is bad, just saying don't be so sure the part is good just because its new and especially when it comes to these stupid walbro fuel pump inserts. I have put in 3 total that had worse fuel pressure than the stock one that was failing and had to "REDUE" the pump. Twice on my ng900, once on my 9k aero and once on my girls 9k.

They suck and have a very high failure rate, I don't trust them at all and always check my systems with my fuel pressure gage and wide-band.

Rant of the day :)

John
 

·
Registered
Joined
·
4,335 Posts
.039" is a little high for your power level, .034 would be closer to what you need and remember the boost pulls the gap apart, so they need to be replaced every so often.

I learned the hard way that just because a part is new does not mean its working fine. I am on #4 fuel pumps that have been bad right out of the box. I do not trust the walbro inserts at all and there have been a lot of people with pump failues this year and two that only lasted a few months.

My local indy shops have stopped replacing fuel pumps with inserts, the failure rate is just way too high and if you look at eeuro, they no longer sell the insert because of the failure rate.

Not saying your pump is bad, just saying don't be so sure the part is good just because its new and especially when it comes to these stupid walbro fuel pump inserts. I have put in 3 total that had worse fuel pressure than the stock one that was failing and had to "REDUE" the pump. Twice on my ng900, once on my 9k aero and once on my girls 9k.

They suck and have a very high failure rate, I don't trust them at all and always check my systems with my fuel pressure gage and wide-band.

Rant of the day :)

John
Is the viggen pump different, better, etc??
 

·
Registered
Joined
·
247 Posts
Discussion Starter · #17 ·
.039" is a little high for your power level, .034 would be closer to what you need and remember the boost pulls the gap apart, so they need to be replaced every so often.

I learned the hard way that just because a part is new does not mean its working fine. I am on #4 fuel pumps that have been bad right out of the box. I do not trust the walbro inserts at all and there have been a lot of people with pump failues this year and two that only lasted a few months.

My local indy shops have stopped replacing fuel pumps with inserts, the failure rate is just way too high and if you look at eeuro, they no longer sell the insert because of the failure rate.

Not saying your pump is bad, just saying don't be so sure the part is good just because its new and especially when it comes to these stupid walbro fuel pump inserts. I have put in 3 total that had worse fuel pressure than the stock one that was failing and had to "REDUE" the pump. Twice on my ng900, once on my 9k aero and once on my girls 9k.

They suck and have a very high failure rate, I don't trust them at all and always check my systems with my fuel pressure gage and wide-band.

Rant of the day :)

John
Thanks John, everyone should get the opportunity to rant once in a while. :)

Well, I put 100 miles on her in the past 2 days and really drove pretty hard for the most part but had not one single issue. The car just drives really well, I will take your advice and gap them to .34 next time. Oh, and no CEL!!! I am now going to go out on a limb and say that it is solved. The cure: have a new shorter rear o2 bung welded closer to the cat for anyone with a JSP downpipe that is pulling a CEL for oxygen sensor related issues.

Edit: I change my plugs every 1,500 miles and the oil every 3,000 or less.
 

·
Registered
Joined
·
4,857 Posts
That is good information and it went along with what we were saying about getting the sensor closer to the cat. Sounds like it might have just been a fluke on the issue. Glad you got it running in sunny California :)

John
 

·
Registered
Joined
·
247 Posts
Discussion Starter · #20 ·
That is good information and it went along with what we were saying about getting the sensor closer to the cat. Sounds like it might have just been a fluke on the issue. Glad you got it running in sunny California :)

John
Thanks John, it was just a nagging issue that took away from what is otherwise a perfect car and now that is resolved. I just like knowing the the car is running without an issue, and am glad this fix worked.

I know some other people who have a JSP ss downpipe with the same CEL issue and hope this will help them out too.

Christian...I had a fuel cut once and PMed John at JZW...He also suggested gapping down to .34...That was it for me.
Hey Josh, how's it going man?! I will try to give you a call later and catch up a bit, its been too long.

Thanks for the info, I will gap them to .34 next time... I wish I would have known that because I would have gapped them to that instead of .39!
 
1 - 20 of 20 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top