Thumper Posted March 9, 2006 Share Posted March 9, 2006 Ok I just swapped out an oil pump and a n/a cam into my z. The cam was off of a n42 head so I had to convert to external oiling. The car will not idle. But it will rev fine. I can hold the the throttle open and keep it running at 2000-2500rpms. If I let it go down to idle the vacuum will be around 5-0 mmHg. At higher idle 15mmHG. Upon deceleration 20+. The distributor timing is correct. The mark in the cam gear lines up perfectly with the mark on the cam tower. I am in the no.1 position. Both of the no.1 cylinder cam lobes are facing up. And are opposite each other. Maybe just maybe I am off one tooth but from what I can see I don't think so. Any suggestions please help? I knew I shouldn't have touched the car it was running so good. Quote Link to comment Share on other sites More sharing options...
Thumper Posted March 9, 2006 Author Share Posted March 9, 2006 Well I moved my cam two teeth forward and two teeth back and compression got worse and then alittle better still not good. So I put the cam back the way I had it and installed my stock cam and bingo it worked perfectly. So... My theory is that the cam with higher lift is overpowering my hydraulic lifters at low rpm/low oil pressure. Then when i rev it oil pressure goes up and then they work normal. So basically my hydraulic lifters cannot handle the higher lift of the A cam out of 75' 280z. Well there went 6 hrs of my life:icon51: Quote Link to comment Share on other sites More sharing options...
ZSaint Posted March 10, 2006 Share Posted March 10, 2006 I just went through this same drill with my 3.0 with a P90A head. I finally have a solid cam in it and solid adjusters. This is the 4th cam I have had in this new engine. I gave up on the hydraulics. I converted to solids. 4 cams in 156 miles! Not bad, right? Quote Link to comment Share on other sites More sharing options...
Thumper Posted March 10, 2006 Author Share Posted March 10, 2006 I just went through this same drill with my 3.0 with a P90A head. I finally have a solid cam in it and solid adjusters. This is the 4th cam I have had in this new engine. I gave up on the hydraulics. I converted to solids. 4 cams in 156 miles! Not bad, right? Sounds like me with oil pumps and turbos. Did you get adapters machined or did you install a p90 solid head? If you got adapters machined how much did it cost. Thanks Quote Link to comment Share on other sites More sharing options...
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