Tuesday, January 16, 2007

ej25dohc into ej18 car faq

okay. i have a 93 FWD L. 5 speed, ej18 car, i have a 98 DOHC RS motor (from an automatic RS) in my car now.
its a FWD with rear disc conversion +gastank.crossmember.sway blah, but this last conversion has driven me to nuts.

but - it runs, it pulls HARD, has no bogs and IT IDLES!!!!!!!!!!

its using
-1.8L engine wiring harness
-1.8L ecu and all wiring
-1.8L radiator / fans
-1.8L FWD tranny, flywheel, clutch (cable)
-1.8L crossmember
-1.8L throttle body with intergrated TPS and IAC
-1.8L MAF sensor, airbox, intake pipe
-1.8L ignitor
-1.8L charcol canister
-1.8L fuel pump
-1.8L fuel lines / filter
-1.8L brake booster line
-1.8L throttle body coolant line
-1.8L PCV setup

-2.5L DOHC motor
-2.5L intake manifold
-2.5L injectors
-2.5L sensors (all)
-2.5L coil packs
-2.5L plug wires

disabled (bc my car dosnt care anyway)
- no EGR - block off plate fab'd with alcoa 6061 t6 and dremmel tool
- blocked off IAC on manifold - use ej18 throttle body unit
- 1 million vacume lines blocked off - block off everything that u dont need for the bare essentials

--u can use from either ej18 or 98 DOHC ej25:
--throttle body gasket,
--exhaust manifold (they are the same dimensions - i measured them),
--catalytic convertor - EJ25 is bigger though + same for exhaust
--water pump - same part number
-- radiator cap - ditto although GDA is same also and supposedly 1.1 bar pressure (higher --> better)

**issues - ej18 powersteering lines are bent wrong for the ej25 motor, so it makes taking intake manifold off a hassle. also, u need to use the ej25 bracket to mount it on the engine with.

************************************************** **

it is a simple swap.
everything bolts in, mates up etc.

what i had problems with:

1. my ignitor was toast to begin with. i ran on front 2 cylinders for a while before i realized that #2 and #4 wernt getting spark. BTW your engine will run with the front 2 cylinders only, its slow but not that bad for 2 cylinders.
2. i had a million vacume leaks. use the charchol canister and its ej18 setup
3. ej25 powersteering pump has no plug on it. i have no idea what the ej18 plug on it does. so far, no issues
4. make sure your intake manifold gasket is good. mine was destroyed (by my stupidity and not recognized untill now). toast by #3, leads to intake manifold backfire in #3 and horrible loping idle.
5. dont mix up plug banks from coil. ie making #2,#4 fire at #1,#3 times. BAD.
6. i thought my headgasket was toast (it was the 3 layer). it probbly wasnt, but 13 hours yesterday made me have the new shiny metal 4 layer gasket . shiny. metal. 4 layer headgasket to take more boooooost...... its not that hard to swap. if u have some monkey knowedge, do it yourself. u need 2 friends to hold the cams in place for the left bank (#2/#4) they need to be centred @ lift and will spin out - scary noise if not attended to. note - GDA manual works perfectly - even the teeth #s are the same for spacing for the DOHC motor. same lifter setup etc for 87-98 dohc ej25. 96 is hydro lifter.
7. issues with bogging - not really. i dont have any bogs in my powerband. im guessing its not ideal - 1.8L map, but its not very far off.
8. redline issue = YES . it cuts at 6,000 rpm. im going to get it hacked to 7,000 by yoshio - hopefully with better power curves................

hmm anything else...... blah. i need to sleep right now. oh yeah, if u can rent / steal / buy an engine crane, id suggest u do so. we dropped the entire crossmember and jacked my car up a million inches to slide from underneath. its not bad, but the steering gear line up procedure SUCKS. (got it missmatched 4 times) blah.

any questions, hit me. pm me email me aim me, whatever. hawk296 is the bomb. hes saved my arse so many times on this swap........



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