no power ka24det

[Gutling]

its a 93 240sx coupe se. auto ka24det
recently came in with blown headgasket due to overheating (car wouldnt start, comp test showed like 15-20-32-10, radiator was dry.) rebuilt head, new gasket, replaced waterpump (dripping from weep hole) new thermostat, and the car cranks now. has horrible power, wont go past 35-40mph, wont rev past 3500rpm (will for a sec when u floor it, like 4k, then holds at 3500 as long as u got gas held down)

known problems with car - knock sensor, coolant temp sensor, horrible exhast leak somewhere after exhaust manifold, some nasty wiring somewhere (in netural when u rev it, the mph jumps from 0 to like 90 and stuff)

mafs was bad, replaced that, mafs is good now according to ecu and mafs voltages

what else is possible, should i look at, or would any of the above problems be causing this?

[Wykydtron]

Could it still be in safe mode?

[koukimonster139]

uhhh fix the known problems list that you have?

[Gutling]

its not my car its for someone else. they dont want to fix anything they dont have to (read CHEAP ASS) lol it really just needs a new motor first thing i told them (bottom end knocking like a woodpecker) but they want to ride it out.

[MELLO*SOS]

Yes, I think your Knock sensor problem is throwing a code 34, which causes the ECU to pul timing and giving you the shitty performance. Inspect your wiring harness to the knock sensor, and test the sensor itself. For diagnosis purposes only you can bypass the knock sensor with a 1M-Ohm resistor (search around for details).

Pull the codes and see what poor excuse it gives you.

[Phlip]

^^^ What he said.


... then shoot your friend in the kneecaps for being a cheapass, the problem will never go away with patchwork fixes. Fix it right once, or fix it wrong several times.

[Neejay]

its not my car its for someone else. they dont want to fix anything they dont have to (read CHEAP ASS) lol it really just needs a new motor first thing i told them (bottom end knocking like a woodpecker) but they want to ride it out.
That's being ridiculously cheap...

Fix the shit that needs to be fixed, then after that's done and there are still problems, troubleshoot. Patch work just leads to more problems...

[Gutling]

knock sensor is physcally broke (Cracked in half) seen it when head was off. and those were the codes it gave (got a nissan consult II) knock-coolant-mafs(fixed) cleared them all after fixing mafs and got knock-coolant back. i thought the knock would pull timing if it threw a code, but i didnt think it would be that bad. ill get that done next. and yes i know patchwork is bad, but like i said its not my car, i can only do what they want to do. i thank yall for the info though and ill get back after knock replacing

[koukimonster139]

uhh nobody is forcing you to do janky work.

[MELLO*SOS]

It was pretty bad on my N/A KA, but it would still rev all the way. Either way the KS code definitely isn't helping your friend's performance... Get that fixed and move on to whatever the other/next issue is..

[Gutling]

big duh moment for me, even if i replace the knock sensor with a brand new one, its still going to throw the code b/c the engine is knocking isnt it? doh so still going to safe mode. im going to try that resistor trick to bypass it first and see if that fixes it

[Neejay]

big duh moment for me, even if i replace the knock sensor with a brand new one, its still going to throw the code b/c the engine is knocking isnt it? doh so still going to safe mode. im going to try that resistor trick to bypass it first and see if that fixes it
...lol...that engine is gonna take a shit and die. :-/

[Dream240]

big duh moment for me, even if i replace the knock sensor with a brand new one, its still going to throw the code b/c the engine is knocking isnt it? doh so still going to safe mode. im going to try that resistor trick to bypass it first and see if that fixes it

ummm....isn't the knock sensor the one inside the distributor area?
Can't remember where it is.
Well if the engine is still knocking AFTER you replace the knock sensor, you still need to reset the ECU. unplugg the battery for 5 min. Then re-check the codes.

Also....just a wild guess but have you checked the timing? It should be at 20 deg. BTDC. Stock timing. Maybe someone got in there and loosened the dist screws and jarred in a lil bit....maybe???

hope this helps.

[Gutling]

knock sensor is right under the intake manifold, in between the upper and lower runners actually. and i know the engine is still going to be knocking, because it actually physcally is knocking lol, sounds like a rod is on its way out the side of the block