'91 Accord LX 4 cyl. 5 spd. 127K miles - runs fine most of the time but it's not pushed hard. When it gets up around 5000 RPM it cuts out (feels like it dies suddenly, but ultimately keeps running) and shows the CEL. The light goes off when the key is turned off and the engine restarted. The ECM gives me a code 4, which points to the crank position sensor. The driver usually shifts at 3500-4000 so he doesn't usually get the problem, but occassionally it will do the same thing at lower RPM, or even when just holding speed in a lower gear.

Is this an indicator of the timing belt getting sloppy? I don't know for certain when the belt was changed (second owner). I just fixed an ignition problem (ignitor) but this problem has been around since before that one. My thought is that if the belt is just a little sloppy (or stretching), the crank position sensor will give a fault indication when the belt gets stretched. Am I off track? Any ideas?

 

If anybody know i would like some info. i get the CEL for my CPS but i just changed my timing belt and my Distributor.

 

well, I was getting codes 12 (EGR valve lift sensor) and 21 (Variable Valve ...). I also changed my timing belt last week.

I also installed a starter kill relay where I had to cut the ignition wires. I disconnected quite a bit of harnesses in the process. One harness was the Variable Valve thing. Everything I disconnected was in the general vicinity of the Variable Valve thing and the EGR valve things.

but i know that that variable valve issue will not allow me to rev up in the 4500+ rpm range.

do you have VTEC? have you been poking around the engine bay lately. perhaps you knocked a harness out or forgot to plug one back up.

 

JiggaFan,
No VTEC. No loose or open connections that I've found ('course that doesn't mean they don't exist - it just means I haven't found any). No other trouble codes since the ignitor was replaced (that was a 15), just the 4.

HatchCX,
If you just changed timing belts and have the same light, maybe this thing doesn't need one. What about your tensioner - did that get changed out when you changed belts?

Anyone,
How many degrees is one notch on that belt? If it's 3-4 degrees and it's advanced, it would idle rough and low, but run like a scalded bear at high end. But what if it were one notch retarded???

 

got any more ideas?

 

no i didn't change the tensionor. If it required to do so??

 

I have a d16z engine turbocharged boosting at 0.5 but have consistently giving problems each time i rev over 5000 rpm....especially after 3rd gear. I've consulted a few workshop and had many different answers....however, two of them told me that it is my stock ECU and MEP sensors which are the cause of the problem. This is because they can't read the additional air that is pushed in by the turbo.

How true is it? Opting for a programmable ECU like HALTECH seems a little overkill for this problem.....does anyone here have any opinion. Would relly appreciate it . Thanks

 

u should check the timing belt for wear, if that checks out ok, then u could check the sensor itself(crankshaft position sensor), or the timing belt tensioner.

 

Make sure that your spark isn't getting "blown out". This has happened on my turbo'd Miata at high rpms in 4th & 5th gear, a new set of plugs & wires, along with a tighter gap, seemed to do the trick.

What are you using for fuel enrichment while under boost? Rising rate FPR?

 

if the accord is equipped with a cam position sensor, a sloppy belt could set a DTC for the crank position sensor because it is not in sync with the cam sensor.

if the crank sensor is a hall effect, check to make sure it is getting a 5v reference signal from the ecu. if it is, use a lab scope to check the waveformit is sending; it should be a digital (on-off) signal, and shouldnt have any hash.

if it is a VRS, hook the lab scope up to it and make sure it is creating a good a/c voltage signal. keep in mind that you should see a spike in voltage once every revolution due to a missing tooth on the reluctor wheel for sync purposes.