Having some trouble diagnosing an CEL issue I've been having on my street/track EG coupe with a B18C1. I've outfitted it with a Moroso baffled road race pan, MFactory oil cooler and external oil filter, as well as a 3-quart Moroso Accusump. So the brings my total oil volume up to around 10 quarts. When driving, I'll get a CEL light at random times. Sometimes right after I start driving, sometimes 20 mins into a drive, sometimes not at all. When it DOES come on, its always when I'm driving it hard and revving it high, but i cant ever seem to duplicate it when I want to. Is it possible that the oil system with the accusump is either pumping too much oil into the motor, or the opposite and drawing too much oil from the motor when its filling and causing my CEL? Any experience with a setup like this would be greatly appreciated.

 

It hurts my brain trying to remember, but I think when Kiwi was testing accusumps in various configurations and what not a long time ago he found that sometimes he would see a drop in oil pressure caused by the accusump refilling. Everything would be fine in a hard turn, but upon entering a straight, he would see a drop in pressure that he could only conclude was created by the accusump refilling.

 

It does make sense. In theory, the accusump is a great failsafe feature to protect the motor in many ways. However, it feels like its better suited for higher displacement motors with larger oil systems. For a B-series honda, it just seems like that +/- 3 quart surge to the oil system is just too much, especially considering the constant high pressure it needs to maintain for VTEC. I've tried running the car with the valve to the accusump closed off. It did seem to help (drove the car longer before the light came on) but at that point I'm just not sure how much oil is trapped in the acccusump. Close it off with the engine off and the accusump is empty, or close it off while at idle?, or under a load with pressure and the accusump is partially full? I dont know its just frustrating to have this ghost CEL that comes on at random times with no rhyme or reason that i can pinpoint.

 

have you thought to pull over and check the code for the light? pretty good way to see if it is oil pressure related or not.

if it's higher in the revs, it might be a misfire or VTEC related fault...