BOOOOOOOOst

[Fast_Ed]

Well, the SAAB is back on the road. And thus, I have a new litany of issues to describe on the forum.

Actually, few of them are new, but many still exist. For example, the car still doesn't boost all the time.

It boosted successfully for it's last legal drive (before yesterday) on New Year's Eve. But a drive earlier in the week showed no boost. And I got a check engine light for the Boost Control Valve (BCV) not being connected. My BCV has a single connector, which was broken halfway off. Seemed a likely suspect, and at $50 shipped, at least I would have a physically intact valve.

I installed the BCV last weekend in prep for my inspection yesterday. It hesitated under boost on the way to the shop once, and boosted normally the second time. If this was a failing turbo, why has it not failed already??

Anyways, of course I drove it to work today. It boosted fine once, then no boost the rest of the 50 mile trip.

The next culprit is the bypass valve (BPV). I was going to do diagnostics, but then I noticed that they are only $20 on Eeuroparts. So I ordered one.

If the BPV has failed, boost pressure will pass from the pressure side of the intake back to the preturbo portion. It would not be leaking unmetered air because it would not leave the system.

Hopefully this finally solves that issue.

[kevm14]

Well, the SAAB is back on the road. And thus, I have a new litany of issues to describe on the forum.

I enjoy the fact that the car not being on the road prevented you from having to think about (or should I say, deal with) all the other things that may need repair. Which explains why it took much prodding to do so.

Actually, few of them are new, but many still exist. For example, the car still doesn't boost all the time.

Well, if it did, then you'd get terrible fuel economy...so that's a feature.

It boosted successfully for it's last legal drive (before yesterday) on New Year's Eve. But a drive earlier in the week showed no boost.

Please, tell me more about these other types of drives.

The next culprit is the bypass valve (BPV). I was going to do diagnostics, but then I noticed that they are only $20 on Eeuroparts. So I ordered one.

Not enough "E's." I know you're not stingy with your repetitive letters, because I see the thread subject.

If the BPV has failed, boost pressure will pass from the pressure side of the intake back to the preturbo portion. It would not be leaking unmetered air because it would not leave the system.

And thus create some kind of perpetual air system! Quick, file a patent!

Hopefully this finally solves that issue.

Your optimism is alarming. And I believe you will find this post quite (un)helpful.

[kevm14]

I'll try this recommendation again: can you see about locking the waste gate shut? Is there a practical way to do that? Yeah it'll piss Trionic 7 off but you can probably just avoid RPMs over like 3,000 or whatever rpm you think the turbo won't boost more than the engine/fueling system can handle. Somewhat risky but I still think somehow that system is not working right, and I don't think it's the turbo failing.

[Adam]

I'll try this recommendation again: can you see about locking the waste gate shut? Is there a practical way to do that? Yeah it'll piss Trionic 7 off but you can probably just avoid RPMs over like 3,000 or whatever rpm you think the turbo won't boost more than the engine/fueling system can handle. Somewhat risky but I still think somehow that system is not working right, and I don't think it's the turbo failing.

Have you tried replacing the wastegate?

[Fast_Ed]

The wastegate is part of the turbine housing. It boosted fine the whole way home... so confusing.

As its an intermittent problem, I don't think holding the wastegate shut is practical. I wonder if the actuator just stuck open again? It was pretty nasty when we worked it open and closed that one time. And it didn't get moved again until today, probably.

I found out about a giant Saab junkyard in Warwick (not my house).. Maybe I can get a used actuator there? Of course, I would have to check it's motion...

[Adam]

The wastegate is part of the turbine housing. It boosted fine the whole way home... so confusing.

As its an intermittent problem, I don't think holding the wastegate shut is practical. I wonder if the actuator just stuck open again? It was pretty nasty when we worked it open and closed that one time. And it didn't get moved again until today, probably.

I found out about a giant Saab junkyard in Warwick (not my house).. Maybe I can get a used actuator there? Of course, I would have to check it's motion...

I meant replacing the actuator.

[Fast_Ed]

I meant replacing the actuator.

I know, I was just being obnoxious. It boosted fine all the way here today as well. Probably just wanted another $30 spent on it. It IS a saab... I'm hoping the actuator just needs regular exercise to keep it clean.

Though, a new used actuator is probably cheaper than a ticket. Full boost is the only way to exercise the actuator.

I found an entire forum about tuning SAABs: trionictuning.com

And, for those that are afraid of CAN-BUS cars for tuning, here is the solution:
https://canusb-shop.com/index.php?route ... duct_id=51


You can also do a $15 connector straight to the ECU, but you have to solder in the connector. And it is a good idea to do this to a spare ECU rather than the original...

[Fast_Ed]

Well, it boosted fine all week, while waiting for the BPC to arrive (today, supposedly). I was beginning to wonder if I had wasted $30 (with shipping) on the replacement BPC. Well, it's 166k old, and something that wears out, so I figured it would be worth swapping anyways.

Today, coming over the bridge under a decent amount of boost, it felt like something gave way and the boost dropped to nothing. Not sure if I was at full boost, though it would be nice to know. It didn't boost the rest of the way in. After parking, I played with the actuator to see if it would snap closed or something. It didn't appear to.

Hoping the BPC solves this issue. I'm fairly confident that the car will boost on the way home, as it tends to do.

[kevm14]

This thread is an advertisement for turbo V8s. That way when there's a turbo issue, you still have 450 hp. Sorry for the convenience.

[Fast_Ed]

OK, so I finally got the Bypass Valve into the car last night. It did the 'boost thing' again on the way home, so I took the five minutes to do it that night.

This morning I tried some more 5th gear boosting, and it did it again. Under boost, a sudden loss of power like a fuel cut. No boost after that. A couple boost free miles later, I pulled over and turned the car off. Counted to five and turned it back on again. Boost returned immediately. Boosted the rest of the way to work.

I was gentle with it on the way home, but it boosted when I asked it to.

I actually think it's plugs. I was still running the old ones from 2011... I found out today I can run copper ones for $2 apiece vice the $13 each for platinums.

I had both of my turbo SAABs do this when they needed plugs. I replaced with copper NGK's on the second one and it boosted like crazy all of a sudden! I remember hitting fuel cut on my return trip over the newport bridge. Someone had messed with the APC (Automatic Pressure Controller) screws. I turned it back down just enough and that car was pretty fun.