dogbert

Gentleman (and Ladies),

The Car: 2002 Honda Civic EX Vtek, 127,000miles - Timing belt, tensioner, water pump and gaskets replaced about around 110k

The Problem: Just appeared ~1week ago out of thin air (wife’s daily driver)
*Rougher than usual idle
*Intermittently the car will want to hesitate when accelerating from idle, seems to struggle to get the rpms up (~700-2000) and then seems ok once it gets going. When this happens it normally throws P1129 and then the rev limiter kicks in (assuming this is ECU controlled). I can drive the car and nothing seems out of ordinary other than a slightly rougher idle( while this could be in my mind I doubt it because I was always impressed with how smooth this car ran for its age and mileage) seemingly out of nowhere after a stop(stop sign or light) the hesitation mentioned above happens.

Searching various forums (including this one) has only yielded one similar case and the individual went through exhaustive measures replacing MAP, O2, Cats etc only to find out the timing belt had jumped a couple teeth. I am going to check this tonight (not looking forward to this job as the timing belt swap was a PITA). I am mechanically inclined and do all my own maintenance but am by no means a professional or particularly enthusiastic about jobs such as these.

*If any one has any other ideas or thoughts please let me know.
*Can someone explain how the timing belt could have slipped a couple teeth?

Thanks in advance for any help/thoughts

ezone

Does this car have a manual trans? Parking in the wrong gear, on a hill, without the handbrake set tight could let the engine roll backwards, that can cause the timing belt to jump.
Where did that tensioner come from? If it wasn't factory, it is immediately suspect.

You'll have to open up the timing covers to see what actually happened. Then YOU can figure out why it jumped, IF it actually jumped.

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P1129: MAP signal higher than expected
Factory info seems to indicate that the only possible fix is a MAP sensor, and some of us know that isn't always right.

At warm idle, in park or neutral, no accessory or electrical loads---
Is the MAP value higher than 1.1v when viewed on a scantool datalist? (Or backprobing with a DVOM)
Is manifold vacuum actually lower than it should be when checked with a mechanical vacuum gauge?
Look for anything that would cause manifold vacuum to be lower than it should be. Cam timing is probably one of the first things to inspect, especially if it has low power.