ca18det trouble!! long read please help!!

[krabstarr]

hey guys

i have some very frustrating problems with my ca18det ever since i have rebuilt the engine.

basically this was what was done to my engine:

- bigger pistons (83.5 mm) wiseco
-wiseco multi layer steel head gasket
-crank and rods balanced with SPEC clutch.
-used grinding paste to clean up valve seats
-changed valve seals
-tomei high lift speings 10.25mm lift (around)
-stock cams and stock camshafts
-sr20det t25 turbo
-new gaskets everywhere

and that pretty much it., i also took off the little flaps inside the intake that help the car idle better (apparently) along with the valve looking like thing that actuates the flaps (left the rod inside)

so basically, before i rebuilt my engine, it was running practicly perfect besides for some little idle problems and a misfire once in a while(didnt gap plugs and i used iridium :P)

so ever since i rebuilt the car, i have a hell of a hard timne starting the car. it takles around 10-20 cranks before it starts up fine and in between those cranks, it starts up and then dies a couple of secs later. i have this problem when the engine is cold only

also, when the engine is cold, when i press the gas pedal too much, the engine just shuts off almost. what i mean is that ni press the gas and it stops firing or anything, the idle just goes down slowly as if i wasnt pressing the gas pedal at all.

then as the engine gets hotter and reaches it p[eak point, when i floor the gas suddenly (under no load) it backfires a few times at 3000 rpm and then goes up to whatever rpm it cuts off at.

when i take my car for a drive its a different story, when i press the gas gently while driving, it doesnt seem to have any problems besides for a lack of power for a few seconds while the turbo is spooling for some off reason (in low rpm's) then once i reach around 3500rpm it start to sort of misfire or something. but then if i release the gas and restart poressing it gently, it revs up slightly higher and then starts misfiring /backfiring noise again.


when i floor the car, it start pulling up to around 3500 rpm, but then it just starts misfiring/backfiring liek crazy and the car stays at like 4000rpm!


i tried everything from timing to cehcking resistance and connections to all the electric components and even checking all the vaccum leaks on the intake!

THERE IS NOTHING WRONG WITH THE CAR i think

DID
I FORGET TO CHECK ANYTHING OR SOMETHINBG??

is it possible that wiseco sent be pistons with a higher compression???

please help me guys! its already been close to 2 monthst that i have been trying to figure out the problem! :wtf: :cry: :cry: :cry: :ughug:

[DP_Michelle G]

what other mods do you have? that would also help

[Flybert]

CA18DET's are notorious for coldstart problems. Did you have the problem before rebuilding the motor? There's a whole bunch of idle control stuff you can clean to alleviate the problem. I assumed you already replaced the CTS since you mentioned checking resistances but it might be worth a try. As for you removing the butterfly valves in the intake mani, that is perfectly fine to do. People do it to KA's all the time. Nissan removed the butterfly valves in later KA's even.

[krabstarr]

whats a cts? if you wanted to mention the crank angle sensor, im prtty sure that works since if i spin the little shaft sticking out of it i hear the injects and coils working fine (i even see spark),

basically i have no other mods really on the engine besides for what i mentionned.

also another thing is that when i time the car to the correct timing, i notice that the the CAS (crank angle sensor) isnt withing the range its supposed to be at (i cant put the bolts to hold the CAS in since the holes in the timing cover are hidden behind the CAS.

is it possible that i maybe am off 1 cog somewhere in my timing belt? ike when i take the top timing cover off the check my timing, both cam gears are perfectly alligned with the timing marks, but it could be that the crank sprocket is off by 1 cog :dunno:

as for the cold starts, it mostly the part that when i press thethrottle that stresses me the most since there is a very bad response and that never was the case before i rebuilt the engine!

thanks for trying to help guys, its much appreaciated! :D

[sblack13]

did you even check codes? my nissan truck w/ a ka24 is throwing a code 13 (cts coolant temp sensor) and is running exactly as you decribed.

[F3600]

I used to have a ca18det.

check if you timing belt in corretcly installed. try to adjust timing.
remove the maf to see if the engine start correclty in safe mode.
test the wiring from sensor to ecu to see if all the wire are okay with no short between them (especially ignitor chip wiring).

added: just read you last post .. i'm pretty sure you installed your timing belt wrong redo your installation.