VTC phase gap troubleshooting

K-Series Programmable ECU installation questions / support issues
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Joined: Sat Oct 01, 2011 5:11 pm

VTC phase gap troubleshooting

Post by akep »

Hey guys,

So we have a P0341 on a K24A1 ep3. Stock block, revhard mani, t3/t4 turbonetics, nothing special. This kit came off the same owners original K20A3, using the same kal and ecu, when everything was working fine.

The kal (one of the revhard base maps for ep3), when all cam angles are set to 0, will hold 0. After some decent driving time, P0431 pops up. The datalogs don't show anything, went through Honda's flowchart, we haven't pulled the timing cover to confirm 100% the timing but we did put a screw driver down in cylinder 1 and checked the dash's on the cam gears lining up at TDC. I wanna say its good. like 98% sure its good, i dont know how sensitive the ecu is.

So from reading about the causes, it can be that the chain is stretched and that cams are actually lagging behind the crankshaft. I guess we'll have to confirm that later, the chain doesn't seem to have any slack that would raise suspicion, so we press on to see if we can find something else that might be the problem. It's getting late. Flow chart says to check if the VTC actuator is clogged, stuck open, stuck closed, (in hindsight i should have tested that but im super tired after a 14 hour shift) and then to check VTC lock mechanism and movement.

So in my infinite wisdom, I copy and paste the ep3 revhard cam angle tables to the map and upload it, and I noticed that during any cam command, the cam angle shoots up to 50*, when there is no cam command, it drops back to 0. The cam angle tables only command for 30* max.

Am I looking at 2 different problems, or is it that I found the cause, a failing VTC actuator? I'm going to tear into this and check everything tomorrow but it would be nice to know if anyone could shine some light on this beforehand. We still have the ep3 VTC solenoid and actuator, that is a known good working one.


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Re: VTC phase gap troubleshooting

Post by Hondata »

A phase gap error is usually timing rather than the VTC solenoid.

Check the cam timing from the transmission end of the cams using the sensor wheels, not the chain end.

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