HOrnbrod Posted August 5, 2014 Share Posted August 5, 2014 Understand. :cheers: Link to comment Share on other sites More sharing options...
Jeep Driver Posted August 5, 2014 Author Share Posted August 5, 2014 Yes, I have thought about it but I'm too deep into the Renix. The other thing is this is my DD and for me to do anything mechanical it has to be done in one day or I lose money and make my customers unhappy. And family and I like to eat. Sorting through the wiring alone may take a day or two.....or so I suspect. Link to comment Share on other sites More sharing options...
cruiser54 Posted August 5, 2014 Share Posted August 5, 2014 I might have a new one. Link to comment Share on other sites More sharing options...
Jeep Driver Posted August 6, 2014 Author Share Posted August 6, 2014 Bad news, excessive blow-by. The new ICM brings my idle down low enough to now notice it's struggle for survival. Hopefully I will get enough miles out of it to save up for a new engine. Link to comment Share on other sites More sharing options...
88whitemanche Posted August 6, 2014 Share Posted August 6, 2014 That sucks dude! How did you find out? I've been battling a low idle for a while now but can't really find the problem.... Link to comment Share on other sites More sharing options...
cruiser54 Posted August 6, 2014 Share Posted August 6, 2014 You mean ISC? Idle Speed Controller? How did you determine excessive blowby? Link to comment Share on other sites More sharing options...
Jeep Driver Posted August 6, 2014 Author Share Posted August 6, 2014 You mean ISC? Idle Speed Controller? How did you determine excessive blowby? From my research the ISC is MPI and the ICM is TBI. Idle Control Motor. I wish my camera did good video, I'd hold a pompom over the oil fill hole to show you how much crank case pressure there is. The air forced out is constant, not puffs to indicate one cylinder. I've always had a problem with oil forced into the intake, that is what got me to swap to the aluminum VC. Couple of months ago I installed a new rear main seal and after a couple of days it began to leak, know I know why. I have considerable hearing loss and it's difficult for me to determine the source of noises. I stated that the injector sounded louder than normal, that prompted me to use the poor mans stethoscope method and I still could not find it. So, thinking that I could hear the valve better if I took the oil cap off........wow........I was shocked at the amount of air being forced out. Cruiser, I appreciate the TBI offer but I will need to hold off at the moment as I have bigger fish to fry. From my research last night, the 96+ 2.5s have different rings and pistons. The PO rebuilt a replacement engine and I have no idea what parts he used, without researching the casting numbers.....which would do me no good anyway as he could have used a early block with late rings and pistons.....who knows. But the engine only has 60K miles on it. I found a 97 TJ engine for $200 that I could uses as a core to build a new engine. Kinda looking forward to it.....just don't like being forced to do it. http://www.hesco.us/products/7724/new-products/167924/rvob4-25l-camshaft#.U-IuHv6lW79 You guys trust Hesco RV cams? If not, what about Clifford? Link to comment Share on other sites More sharing options...
Jeep Driver Posted August 6, 2014 Author Share Posted August 6, 2014 If you guys question- why all the sudden? I don't think it has happened all the sudden. The idle has a sweet spot, around 800rpm. The ICM has never worked so I was able to set the idle manually, now that the computer sets the idle I now notice the problem and my compression loss is apparent at 450-500rpm. I guess I'll get a few more months out of it since it's been this way for some time now. I suspect that the ring wear has met critical mass and has now shown itself. Interesting thing is that when I replaced the trans and rear main seal I also replaced the pan gasket and I could examine the cylinder walls, they looked very clean, no scares, no signs of wear, nice and shiny. Link to comment Share on other sites More sharing options...
cruiser54 Posted August 6, 2014 Share Posted August 6, 2014 You've got ISC and IAC/ICM backwards. ISC has a pintle to move linkage. IAC controls air flow through the throttle body on MPI. Do a dry, then wet compression test. Link to comment Share on other sites More sharing options...
Jeep Driver Posted August 6, 2014 Author Share Posted August 6, 2014 You've got ISC and IAC/ICM backwards. ISC has a pintle to move linkage. IAC controls air flow through the throttle body on MPI. Do a dry, then wet compression test. I read many threads last night regarding the 2.5 and blow-by, even with good numbers...120-135 on all cylinders....guys were suffering with high pressures. Apparently this is not uncommon to the 2.5s and no one has an answer as to why. Link to comment Share on other sites More sharing options...
cruiser54 Posted August 6, 2014 Share Posted August 6, 2014 A leakdown and/or wet/dry compression test should tell us something. Link to comment Share on other sites More sharing options...
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