SaabCentral Forums banner

1 - 3 of 3 Posts

·
Registered
Joined
·
9,423 Posts
Discussion Starter · #1 ·
With a title like that...

Okay, so here's the rundown. Ever since the spring, I've noticed a bit more time is needed for the old go fast needle to bury itself in the red. I have attributed it to heat and maybe other things, but...A few weeks ago I installed a new downpipe and while spoolup was improved, it still wasn't the meteoric slap over to the red that I had heard. Well, until yesterday...

Two nights ago, I was doing my standard tinkering. Now, most anyone who's read a sprkplug on here knows I could care less about the whole NGK thing. I don't ever run them anymore. Well, about a month ago, while investigating the slow boost buildup issue, I swapped out the Autolite platinums (gapped to .035) and replaced them w/ some Bosch Supers also gapped at .035. Nothing changed.

Well, let's see, my routine the other night consisted of a.) swapping in the now cleaned autolites and this time gapped to .037. and b.) doing a little combustion chamber cleaning after noting carbon buildup on my piston crowns.


Well, yesterday afternoon on my drive home from work, I was doing some routin acceleration after a truck turned off the road. As soon as I touched the gas, I heard the engine just sing. I let off and did it again, watching the boost needle. WTF?? It went from vacuum to 1/2 thru the red in the blink of an eye! Actually, I could barely keep up! I was taching about 3500 rpm in 3rd gear, not statospheric or anything.


This morning though, everything seems back to status quo. Before this morning, I was figuring that maybe the Bosch plugs were incorrectly gapped or something. But, bare in mind, I had had the autolites on during the same time frame w/ no difference. I promise, I'd be perfectly willing to blame the plugs if I thought they were at fault. Surely it's not just the gap?

But since I'm now back to "normal" I'm wondering if maybe this is something like maybe a wastegate that's sticking open or rather not closing completely? I was up under there though and it seems to move freely when I move the rod. Maybe I'm just more of a leadfoot when I'm trying to GET HOME from work instead of when I am on my way there???

Just looking for input since I only know maybe 2 people here in Shreveport that could properly diagnose this.
 

·
Registered
Joined
·
4,293 Posts
What do you have on the wastegate now, the stock BPC or a manual boost controller? Whichever it is, given my own experience with the BPC, that is where I would look.
 

·
Registered
Joined
·
9,423 Posts
Discussion Starter · #3 ·
MBC+A. I have already fiddled w/ this aspect. I pulled apart and cleaned the MBC. I also suspected perhaps it was the apr still allowing air through even though I have it closed off right now. But, I removed everything and went just MBC and I still have the same issue. I seem to remember switching back to the stock boost control solenoid at one point to test and no luck.
 
1 - 3 of 3 Posts
Top