03 civic LX, only runs with crank position sensor unplugged
 

Please help me, I recently bought a 2003 civic with no engine, and took the engine out of my 01 civic. Which wouldn't run unless I unplugged the crank sensor and ran it in limp mode. So I changed the crank sensor then put the engine in my 03 civic and it's doing the same thing. Starts for about 2 or 3 seconds, sputters, bogs out and stalls. So I unplug the sensor and it starts up and runs okay until 3500 rpm due to limp mode. I cut the old crank sensor connector off and spliced a new one on. And still the same thing, is the computer thinking its out of timing? Bad wiring somewhere? Please help its my daily driver! Thanks!

Re: 03 civic LX, only runs with crank position sensor unplugged
 

I'm also curious about a sound that this engine has had for quite a while now, it's a loud ringing noise that follows the Rpms starting around 2000, getting louder the higher it revs. It's on the back side, maybe in the intake manifold? Butterfly valve or something? Maybe it's common for the D17, doesn't seem to effect the engine, but it could be and I'm just not noticing it. It's fairly loud and annoying

Re: 03 civic LX, only runs with crank position sensor unplugged
 

Got fault codes?

I'd suspect it has jumped time.

Research all timing marks and alignments for cam gear and TDC for crank pulley.
Pull valve cover and upper timing cover and verify timing belt has not jumped a tooth or more.


The computer will shut down the engine if it's too far out of time (cam-crank signals out of sync), but unplugging one of the sensors can bypass the failsafe engine kill function.

Noise.....if it's a loud rattle coming from the timing belt area along with a jumped timing belt, the spring for the tensioner pulley may have broken or the ear of the tensioner wore through. (this can also cause the computer to shut it down due to timing error)

If so, use only parts from Honda.
Aftermarket is usually crap and the life of the engine is at stake, the engine bends valves if the timing belt lets go.

Re: 03 civic LX, only runs with crank position sensor unplugged
 

So you're saying this rattling noise I'm hearing could also be the reason the computer shuts the engine down with the CPS plugged in? The engine does see to run ok with it unplugged, minus the bad mileage as rev limiter. Would that mean that it's not far out of timing or?

Re: 03 civic LX, only runs with crank position sensor unplugged
 

Neither the CPS or the plug for it are actually new, they're off the original blown motor that was in the 03. But they're in good shape and the guy that owned the car said it all worked fine till it ran dry of oil, so

Re: 03 civic LX, only runs with crank position sensor unplugged
 

Don't run it any more! Stop now! Take it apart and inspect it ASAP!

If it jumps time far enough or breaks and skips, it will bend valves and that's a boatload of money and work to fix.

Re: 03 civic LX, only runs with crank position sensor unplugged
 

Note that rotating the crankshaft the wrong direction can cause the belt to jump time, even when everything was okay immediately before.

Re: 03 civic LX, only runs with crank position sensor unplugged
 

So I'm looking to see if the belt skipped a tooth on one of the sprockets, and checking the tensioner to see if it's messed. Any other major possibilities? Engines been running like this for 2 years hah

Re: 03 civic LX, only runs with crank position sensor unplugged
 

Based only on what you have written, that's my guess.

Got fault codes?

Re: 03 civic LX, only runs with crank position sensor unplugged
 

Engine light is on yes, last time I had a reader on it there was a code for upstream o2 sensor, and crank position sensor. I chucked another o2 on it from the 03 engine a couple days ago, and CPS, and the plug in. The light is still on though

Re: 03 civic LX, only runs with crank position sensor unplugged
 

I don't have to pull the bottom belt cover off to check the timing I hope

Re: 03 civic LX, only runs with crank position sensor unplugged
 

TDC timing mark on the crank pulley is exactly the same TDC mark on the crank timing gear.

No need to remove the crank pulley or lower cover just to verify, not until it's actually found to be out of time.


If the spring broke or is missing, you might not realize that if you don't already know where it's supposed to be located.

Re: 03 civic LX, only runs with crank position sensor unplugged
 

So take the too cover off, crank engine CCW. Until the cam gear is reading TDC, how will i then determine if the belt has skipped its timing or jumped a tooth? Is there a mark on the belt itself where it should be on the gear or

Re: 03 civic LX, only runs with crank position sensor unplugged
 

Remove splash panel in wheelwell.

Use a ratchet and extensions to reach the crank pulley bolt (19mm).

Rotate crank by hand (tools) to align TDC mark on the crank pulley with the pointer on the lower cover.

The word "UP" must be facing somewhere readable in the north side of the cam gear, not upside down.
Rotate crank one more revolution if needed to get this result.

See if the cam gear marks are not correctly lined up with the flat head surface when crank pulley is on its TDC mark (single notch).

Don't you have a service manual to refer to? Google images?

Re: 03 civic LX, only runs with crank position sensor unplugged
 

Ohh I didn't realize the crank pulley itself had marks on it, I figured only the crank gear under the cover had marks. That makes things easy then lol, thanks for your time and help! I'll check it out in the morning

Re: 03 civic LX, only runs with crank position sensor unplugged
 

I set the timing on it yesterday, was out by a tooth and runs not bad now. Sometimes it'll still rev limit at 3500 though, not sure what wrong now. But I'll deal with it, now just gotta figure out why it sways back and forth on the road, and why there's a gurgling sound in the heater core..air in the lines or something. It'll be a good car eventually lol..

Re: 03 civic LX, only runs with crank position sensor unplugged
 

Erase codes, then run it til it acts up and recheck codes.

But why was it out of time in the first place?

Gurgles=low coolant, trapped air.......Where did this come from......head gasket?

Re: 03 civic LX, only runs with crank position sensor unplugged
 

The belt was replaced by the previous owner , maybe it wasn't properly aligned when it was put on. Because the belt is real tight, it was miserable to get off and on even with the tensioner loose, and I'm gonna run the engine with the heater on full wit the rad cap open and keep topping it up some more, hopefully get the air out of the system. It went above operating temperature today also.. Hoping its airlocked and not the head gasket, oil is fine so

Re: 03 civic LX, only runs with crank position sensor unplugged
 

When I put the engine in this car maybe I didn't properly bleed the coolant system, after all this work I hope the head gasket is not leaking

Re: 03 civic LX, only runs with crank position sensor unplugged
 

They are notorious for hard to diagnose head gasket leaks....and they almost never put coolant into the oil, nor vise-versa. The usual head gasket leak pushes coolant into the reservoir and leaves the radiator low. Find the 'overheating common causes' sticky thread for more info.

Many people replace the whole engine just because of a head gasket, but then they install a used engine that also needs (soon or now) a head gasket.