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basically i just got this 2004 civic ex coup to build up, i drove it and i can barely tap the gas without it backfiring completely and just reving as if it’s in neutral, when it revs like that or just parked it won’t go past 3500 rpms, put it on a computer and nothing showed up, i’m all outta ideas here and thought this sight could help me out cause it’s been stuck like this for a while..any ideas would help and would be much appreciated also changed the amf senser and cleand out the gas valves, all the coils and spark plugs are brand new, just changed the thermostat cause it had a slight overheating problem, previous owner ripped out the brain the the alarm but it looks professional, the camshaft position sensor was replaced 2 times before, dad’s saying the vtec could be disconnected and maybe that’s why but i’m out of ideas here and idk what to do any ideas?
dad’s saying the vtec could be disconnected and maybe that’s why
That's an easy check. here's the VTEC solenoid (standing in front of the car, it's going to be the thing with the gold-ish cylinder on the backside of the engine, left side, behind the valve cover). You may need to remove the intake filter box to get a good look, but that's fairly easy to take off.
See if the electrical plug is connected to anything. If the ECU is trying to send a VTEC signal and there's nothing there, then yeah, it'll toss you into limp mode.
sorry for tue late reply, just checked all the wiring it’s all good, even herd the ticking when i start the car, but my dumb self forgot to check the simple stuff to find out i’m low on oil, my pride hurts a little but it happens, i’m on my way to get oil right now i’ll update when i put it in.
update since i forgot, oil made it noticeably run better obviously but still not going past 3500rpm’s, with the vtec solinoid everything seems to be plugged in so i’m at a loss again
but my dumb self forgot to check the simple stuff to find out i’m low on oil, my pride hurts a little but it happens,
Dude, that happens to all of us.
"Did you check this...?"
"....damn it..."
Originally Posted by jahshua
update since i forgot, oil made it noticeably run better obviously but still not going past 3500rpm’s, with the vtec solinoid everything seems to be plugged in so i’m at a loss again
The light isn't gonna clear on its own. As long as its locked it, it'll keep it in limp mode. If everything is connected, good oil, running seemingly fine below 3500, etc., reset the light and see if it comes back on. If it doesn't, problem is fixed. if it does come back on and tosses you back into limp mode, then you're back at square 1 with the cheapest checks. If you don't have anything to reset the light, disconnect the negative battery cable for like 10 minutes. If you're gonna work on your car, I'd suggest buying a $20 BAFX OBD2 reader and download the Torque app (free unless you wanna pay $5 for the pro license)
Fun fact, a EX with a MT can still get up to 80mph in limp mode. Happened to me with an A'PEXi VAFC-II used to control AFR when I was turbo'd on my 2002. Shop hooked up and set the VTEC setpoints that the ECU didn't like. I didn't have time to disconnect the VTEC controlling part, but I knew the rest of the engine was good to go, so I rolled with it until I was able to revert the wiring.
got you, disconnected the battery but still same result, dad just called me saying he orderd me a new vtec solinoid it comes in monday and i gotta take it to the shop and replace it on my own so hopefully i don’t mess anything up lol, hopefully it fixes the issue so i’m not utterly confused on what’s causing this
have you pulled the actual code that its throwing? Just curious.
Also, if you swap the VTEC solenoid and mess something up, I'd be impressed. About the only things you can do to mess it up is either a) mess up the strainer gasket (kinda hard to do that), b) don't torque it down properly and get a fatty oil leak or c) overtorque the crap out of it and strip out the head. That last one is worst case scenario. It's 3-10mm bolts that hold the thing on and one electrical connector.
