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- #21
Yeah mate... Made it up a while ago.Nice. Is that an ammo-can air box?
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Yeah mate... Made it up a while ago.Nice. Is that an ammo-can air box?
Same mate, it's a 1hdt one... 58020Which turbine housing number does the old one have?
So, I've had a bit of an issue for a while with my engine surging in 3rd and 4th under load intermittently and I need to fix it before I can compare the old turbo and new one effectively. I suspected a slipping clutch at first, but it seemed to improve at times when I switched between my two tanks. Also, one tank felt down on power than the other... That made me think it must be fuel related and I thought it might be fuel starvation. I changed the fuel filters last week and it felt a bit better, but it's still been there intermittently. Anyway... A few extra things on the new install.
1) I put the old boost tee on the new turbo today and it was immediately boosting to 23psi, whereas the old turbo only reached 15 with the same boost tee - any ideas why that would happen? - more efficient turbo?
2) I put a T joiner into the boost compensator line and ran my second boost gauge there for the first time (post intercooler) and I've noticed that I've got a pretty significant drop of pressure across the little front mount intercooler. At WOT this afternoon I was getting 17psi at the cross over pipe (pre intercooler), but only 10psi just before the intake manifold (post intercooler) and the boost is fluctuating post intercooler. It seems to fluctuate when it starts surging, but before this it builds in line with the pre intercooler boost gauge.
3) It mostly surges when under heavy load / acceleration. If I accelerate more conservatively, it doesn't seem to do it as much. I need to do more testing to isolate the specific symptoms.
Also, to be clear, I don't think this issue is in anyway related to the new turbo... I suspect having more air flow is exacerbating the underlying issue, but it's not sure to the turbo. It's something that started about one month ago, but I need to resolve it before I can compare the two turbos.
Any ideas? I'm thinking a boost leak possibly?
I have a feeling that the old turbo might have been cooked... The new turbo has the wastegate set at 14psi, but when I took the boost tee from the old turbo and put it on the new one it was immediately boosting to 23psi. I would have thought that it should have boosted the same as the old one.Difference in boost, unless your old turbo is cooked, is likely due to different wastegate springs
Yeah, my first thought this arvo was to try and bypass the intercooler, so I got one of those horrible flexible connectors, but it was too hard to connect it up. I'll go to a performance parts place on Monday and see if they have anything to bypass it. It's a different setup with the intercooler as the inlet and outlet are on the same side... It's approximately 550 X 160 X 70.Find the flow problem with the intercooler or fit a bigger one and you should be sweet. With 7psi drop your engine will get more air and be happier with no intercooler. So feel free to bypass it for a test
Not so much the Pollak but fuel switches in general. A 75 series owner was having problems similar to you with one tank giving him problems. It turned out to be some some orange plastic, similar to emergency tape I think, inside the factory solenoid valve partially blocking the fuel flow.Any advice regarding the Pollak?
Yeah, I'm thinking of going a single pass in either the same size 550x140, slightly larger at 550x180 or even 550x230... The 180 would be fairly easy to fit, but the 230 would take a bit more work. Would it be worth it for the 230 or do you think the 180 would be good enough?Yeah that intercooler is a weird one. Long flow path but really restrictive. The same size/shape as a single pass would be the smallest you'd want to run and would give about 1/4 of the flow restriction.
Good to hear you've found the problem.
I actually did that this week Rosco. Driving home from work over afternoon it started stalling a couple of times like it was running out of fuel, so I switched tanks and it came good. I even tried switching back, but it almost immediately stalled again. Definitely had diesel, so I switched the inlet and return lines on the Pollak valve to each of the tanks that night and it came good again (actually, both tanks did). Since then, I've had an intermittent fuel starvation issue. Sometimes it's bloody brilliant and pulls really hard and then other times it's doing the same surging, especially in 3rd and 4th... If I switch tanks it seems to help sometimes. My next step is to run a new fuel line from a Jerry can straight to the IP just to confirm that the issue is pre pump. Apart from the fuel issue, the new turbo is awesome.Not so much the Pollak but fuel switches in general. A 75 series owner was having problems similar to you with one tank giving him problems. It turned out to be some some orange plastic, similar to emergency tape I think, inside the factory solenoid valve partially blocking the fuel flow.
Instead of pulling it all apart, maybe you could swap fuel lines to see if the problem is still there with that tank.
Not quite... I've got a factory rear tank that sits between the chassis (holds approximately 70ish liters) and an internal 40 series one that runs across the cab under the seats and holds approximately 90ish liters.Are you running the 75 series dual tanks in the HJ75 chassis?