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44 Posts
So I just bought a 97 obs last week and have been checking it out over the past week. I drove it to work a few days(10 min drive one way) and it was lacking power until 2500 rpm or so, though it didn't really seem to come until I was in 3rd or 4th gear and 2500+ rpm.
Anyways, after driving it to work for the third day and back home, I went and fired it up after it sat for an hour and gave it some throttle but it was slow to rev and started to shutter and blow white smoke around 2500rpm.
When I first got the truck it got new batteries, new oil and filter, new air filter, new fuel filter and cleaned the screen between the bowl and regulator and cleaned the bowl out.
Since the problem started, I have replaced all rubber fuel lines in the valley, removed and cleaned fuel tanks, checked fuel pressure(40-60psi while problem is occurring and about 40 at idle), checked for exhaust and boost leaks(none), shimmed all armatures and solenoids(had less than .002" clearance), unplugged each injector and all cylinders are contributing(I did this at idle and with throttle being held while shuttering was occurring), compression tested all cylinders(340-350 all 8), installed egt and boost(60psi) gauges, no boost showing so I used a vacuum/pressure gauge with higher resolution and I am getting 1lb of boost that's slow to build at 2000+ rpm. Considering white smoke, the fuel is there but not enough air with the low boost. Checked turbo for play in and out(none), side to side it moves about 1mm or so. I spin it and it seems to spin fine but maybe too much drag? Also, if I even slightly put sideways pressure on the turbo shaft it feels sticky while turning.
I have removed and disassembled the turbo and I'm trying to decide what to do next.
Anyways, after driving it to work for the third day and back home, I went and fired it up after it sat for an hour and gave it some throttle but it was slow to rev and started to shutter and blow white smoke around 2500rpm.
When I first got the truck it got new batteries, new oil and filter, new air filter, new fuel filter and cleaned the screen between the bowl and regulator and cleaned the bowl out.
Since the problem started, I have replaced all rubber fuel lines in the valley, removed and cleaned fuel tanks, checked fuel pressure(40-60psi while problem is occurring and about 40 at idle), checked for exhaust and boost leaks(none), shimmed all armatures and solenoids(had less than .002" clearance), unplugged each injector and all cylinders are contributing(I did this at idle and with throttle being held while shuttering was occurring), compression tested all cylinders(340-350 all 8), installed egt and boost(60psi) gauges, no boost showing so I used a vacuum/pressure gauge with higher resolution and I am getting 1lb of boost that's slow to build at 2000+ rpm. Considering white smoke, the fuel is there but not enough air with the low boost. Checked turbo for play in and out(none), side to side it moves about 1mm or so. I spin it and it seems to spin fine but maybe too much drag? Also, if I even slightly put sideways pressure on the turbo shaft it feels sticky while turning.
I have removed and disassembled the turbo and I'm trying to decide what to do next.
. Of course pulling the turbo off could have sprung it worse. You must have quite a leak to not get any boost though. I had my drive side manifold lose a bolt and was leaking pretty good (nice streak of soot down the engine block), but I could still get 10+ psi of boost. Bellowed up pipes and a new collector (to mate with the up pipes) would solve it for good. I haven't managed to get that far yet. Either way the turbo upgrade is a good investment... One that I hope to be making shortly.
