Lude Generation

I found this post submitted in the knowledge base but can't seem to move it.

Posted by @delboy001

hi fellow Prelude owners have a intermittent fault when engine idles really lumpy.Have put new plugs Ht leads lasted a couple hours the other day got home went to run it down to mechanic started her up fine think every time i give her a bit of a burst on the vtec it seems to bring it on. i just love intermittent faults appreciate any ideas. DEL

Sounds like it is ignition based, might want to check the dizzy cap and rotor arm for condition. Possibly also could be a loose wire as it seems to come when gunning it, start wiggling some of the wiring and earth's (particularly the thermostat housing) whilst its idling to see if that makes a difference.

^^^
if its a 4th most likely distributor same for 5th gen but could also be ignition barrel itself (5th gen factory recall)

Vtecmec wrote: ↑

Wed Sep 23, 2020 9:19 pm

hi fellow Prelude owners have a intermittent fault when engine idles really lumpy.Have put new plugs Ht leads lasted a couple hours the other day got home went to run it down to mechanic started her up fine think every time i give her a bit of a burst on the vtec it seems to bring it on. i just love intermittent faults appreciate any ideas. DEL

I'd go with the distributor, partly because A. I had the same symptoms as you, and B. I replaced various items, including the distributor, and that solved the problem.

A faulty distributor will cause overload and failure of the HT leads, it won't affect the spark plugs, and whilst that fault is far more likely to occur under load, i.e. engine load, it does also affect idle too. I replaced plugs, leads, distributor, cap and rotor, but I did them in a structured fashion to see exactly what'd failed. There was an intermittent pulse on the distributor, that was causing a lead to break down and therefore interfering with the spark. I replaced those items, reset the timing and now the engine runs perfectly and low-down torque has been restored.