Slows2k

Did you see anything unusual with the reluctor wheels on the back of the camshafts? Nothing bent or loose?

turbo_pwr

Nope, straight and tight, no play on the wheels at all.

Slows2k

My only suggestions are to verify correct cam timing, if the cam timing is correct, Try swapping a CKP sensor. I know it is in a p.i.t.a. Location, But I have seen older Honda's get confused about what sensor input is bad and throw the wrong code. Do you have access to an OBD2 scan tool that can watch data with the engine running? It may be helpful to drive the car and watch the data list to look for a flakey sensor output. That's about all I have with out looking at the car personally.

AusS2000

How do you get TDC from a sensor of the cams? The cams only spin once for every two revs of the crank!?!? And they can also be out of time (slightly) with the cranks so are not a good indicator of it's position.

Are those sensors really TDC sensors?

Defender

Do you mean that he should verify the proper mounting of the cam chain ?
The following were my thoughts about what other problems could exist - I am thinking it may have something to do with what physically is happening under the valve cover when it goes into VTEC , with that in mind I had the following ideas:

check for proper installation of the cam chain

check for proper engine timing

check the vtec solenoid valve

check the vtec rocker arms

check the cam chain auto tensioner

check the vtec pressure switch

change the spark plugs

check fuel pressure

How about the possibility that the cam chain auto tensioner is not keeping proper tension on the chain - so that at higher RPMS the chain is getting some slack in it and throwing off the TDC sensors ??

Thanks for your ideas and assistance.

Eliot

Defender

How would they become bent or loose ?

Slows2k

The reluctors could become bent or loose because they have been removed from the original cams and swapped to the Toda's. Things have been known to happen to engines that have been apart, I believe turbo_pwr bought the cams used, So most likely they where shipped. It is possible that they where dropped in shipping. Who knows- My crystal ball is out on loan.

The reason I suggested checking cam timing is because of personal experience working on OBD2 Hondas. If you put a timing belt or chain out of time a tooth, The PCM gets "confused" about where the cams are in relation to the crankshaft, and throws a DTC. I don't think that they are out, but it is relatively easy to check. The VTEC solenoid, pressure switch and rockers will not set this DTC, So it wouldn't make sense to bother checking. The only problems I have ever seen with VTEC rockers is from improper assembly, or sludge/varnish build up from not changing oil. Spark plugs and fuel pressure won't set the DTC, I wouldn't check there as well. I would double check everything done on the cam install. Are the Toda cams marked intake and exhaust? You don't have them reversed do you? (Don't laugh I've seen a Infiniti Q45 assembled with 2 intake cams on the same cylinder head) I would also check to see if the correct reluctor wheel is on the correct cam. I would think that if the cam chain tensioner was loose the cam chain would be very noisy, jump off the drive gears or run like total crap all the time if it ran at all. Something is giving the PCM a bad input throwing the DTC. Here is another thought, you don't have the TDC connectors reversed do you? I don't think that the harness has enough slack to allow it, But it's worth a look. I know that these are shots in the dark, Turbo's car ran fine at first, then started messing up. I have heard horror stories of Toda cams breaking, could the intake cam be broken at the rear journal? Let me know what you guys find. Good luck.

Sorry for the rambling.

jmonroig

You need to check the reluctor's wheel runout to verify the clearance between reluctor and plate. Also check if the wheels are
not inverted intake and exhaust or 180deg offset

Defender

SlowS2k, boiler and jmonroig:

Thanks very much for the responses, they are very helpful !! I think some of the suggestions can probably be eliminated because the car does run as it should before it gets above 6K rpms. Please correct me if I am mistaken, but wouldn't the following conditions cause problems no matter what speed the engine was running at:

1) If the the Intake cam was broken at the rear journal

2) If the reluctor wheels were inverted intake and exhaust or 180 degree offset

I don't recall -- do the two TDC sensors on the back of the valve covers take the same shaped connector, i.e., is it possible to switch the sensors by mistake (as I am thinking about this - I think that they mount totally differently - don't they )?

We did not look closely at the cam timing ---- if the chain was even one tooth off that could make a big difference - wish we had done that yesterday during one of the 3 or 4 times we had the valve cover off.

jmonroig: could you give a more detailed description of how we:

"check the reluctor's wheel runout to verify the clearance between reluctor and plate"

and what the "plate" is that you are referring to ? Finally - where do we find the specs for the proper runout and the proceedure to check it ?

Thanks very much.

Eliot

Defender

When we checked the reluctor wheels - we did not remove the camshafts to do so - we looked at them, tried to jiggle them with a screwdriver, and then we turned the engine by hand and watched from the side to see if we saw any wobble to them -- were we checking them the proper way or should we have done something else ?

Maybe we should have cranked the engine with the starter motor and watched them turn ? Should we have taken the camshafts out and inspected the reluctors?

How would we know if the reluctors were installed properly ? Is there something we could read that would tell us about the proper installation (whether one was on reversed or something ?)

Can a reluctor somehow shift postition at higher rpms ? When the camshaft (or is it the rocker arms?) moves as the engine goes into VTEC - is there something that takes place that could some how move the reluctors ?

Finally - the fact that the engine ran fine for a while after the head and camshafts were installed does confuse things .... something had to have changed to have it start to screw up ...
All of the possible mechanical problems would have been there as soon as the install was done and the error code would have showed right away.

I guess that leaves the possiblity of the crankshaft postion sensor having gone bad and the computer misreading the error code ??? That has to be checked...

Again - thanks.

Eliot