DaveSupTT Posted July 27, 2008 Share Posted July 27, 2008 Hi guys, as a few of you are aware I have had a few "issues" with my car, and the time has finally come where I am starting to try and finally get it sorted! Couple of questions. 1) I am trying to do a compression test. I purchased the big set of paper manuals from CJ and im looking at the Compression Check guide (page is EG-39) Im following the guide but I cant seem to find the Camshaft Position Sensor Conectors. Also the manual states I have to disconnect the Solenoid Resistor Sensor Conector, which again I cant seem to find There is a drawing in the manual but it doesnt seem to be much help to me. If anyone could take a photo, or explain where I will find it, it would be a huge help!!!! 2) Can the pistons be removed without taking the engine out? Cheers Dave Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 27, 2008 Share Posted July 27, 2008 Take out all the plugs, remove the three EFI fusees in the main engine compartment fuse box, set throttle to fully open, screw in the compression tester, and crank the engine until tester needle stops going up. Quote Link to comment Share on other sites More sharing options...
DaveSupTT Posted July 27, 2008 Author Share Posted July 27, 2008 Also, on top of my above questions, what is a leak down test and how is it performed? Cheers Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 27, 2008 Share Posted July 27, 2008 Leak-down test is a comparator test between a set supply pressure usually 100psi for simplicity, and the amount of pressure drop/leakage from rings/cylinder and valves, You can buy them, not cheap, but they can also be made. Quote Link to comment Share on other sites More sharing options...
DaveSupTT Posted July 27, 2008 Author Share Posted July 27, 2008 Going back to compression tests. Ideally, what should they all be. From memory, when I had it checked at a Hyper Sports, they said that all cylinders except number 3 were about 200psi, and cylinder 3 was at about 52psi. Looking at the workshop manuals it say min should be 128 and ideally 158psi or more. Mine is a 1993 twin turbo bpu running hybrids if that matters at all. Quote Link to comment Share on other sites More sharing options...
Dave17 Posted July 27, 2008 Share Posted July 27, 2008 52 psi sounds very low to me Quote Link to comment Share on other sites More sharing options...
DaveSupTT Posted July 27, 2008 Author Share Posted July 27, 2008 52 psi sounds very low to me yep, I think I may have a cracked piston head but until I start taking things apart, I wont know for sure Quote Link to comment Share on other sites More sharing options...
DaveSupTT Posted July 28, 2008 Author Share Posted July 28, 2008 Take out all the plugs, remove the three EFI fusees in the main engine compartment fuse box, set throttle to fully open, screw in the compression tester, and crank the engine until tester needle stops going up. I have been looking for the 3 EFI fuses to disconnect but I am unable to find the 3rd one. I have found the 1 and 2 in the main fuse box and its printed on the underside of the fuse box lid. Where is number 2 though? Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 28, 2008 Share Posted July 28, 2008 I was sure there was three, but just remove the two, that will stop the injectors from firing. Quote Link to comment Share on other sites More sharing options...
Homer Posted July 28, 2008 Share Posted July 28, 2008 Those results don't sound right, 200psi is very high and obviously 58 psi is too low. However if there's a major difference the engine is obviously goosed. A leakdown test is far better as it should at least give an indication of where the problem is (valves or cylinder). With your engine's history I'd look towards the head. Off topic: Do a search on hyper too... Quote Link to comment Share on other sites More sharing options...
DaveSupTT Posted July 29, 2008 Author Share Posted July 29, 2008 Cheers Homer, LOL yep I know all about Hyper And I also know all about Max GT who had their hands it as well! Leak Down Test: How do I perform one? Dont really know much about them except for what Tricky-Rick has wrote above. Quote Link to comment Share on other sites More sharing options...
Nic Posted July 29, 2008 Share Posted July 29, 2008 This may help http://www.turbosupras.com/pdfs/JZA80%20TSRM/EM%20(2JZ-GTE).pdf Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 29, 2008 Share Posted July 29, 2008 Here you go, leak-down testing. http://www.carcraft.com/techarticles/116_0406_cylinder_leakdown_tester/index.html Quote Link to comment Share on other sites More sharing options...
MarkR Posted July 29, 2008 Share Posted July 29, 2008 This may help http://www.turbosupras.com/pdfs/JZA80%20TSRM/EM%20(2JZ-GTE).pdf Nice, thanks Nic Quote Link to comment Share on other sites More sharing options...
DaveSupTT Posted July 29, 2008 Author Share Posted July 29, 2008 Cheers everyone for your help! Its really appreciated! Quote Link to comment Share on other sites More sharing options...
rob wild Posted July 29, 2008 Share Posted July 29, 2008 Also Dave to be certain you could always take it to somewhere like Chris Wilsons place to have a endoscopy. He will be able to look into all the cylinders using his kit and give you a diagnosis http://www.mkivsupra.net/vbb/showthread.php?t=20804&highlight=service Quote Link to comment Share on other sites More sharing options...
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