blockhed

What injectors are you using?

Jyrki951

I'm having a bit similar problem. Get misfires when cruising and barely touching gas pedal = no load. As soon as I load a bit the engine, it runs fine. Plugs, coils, variocam brackets and boost leaks checked. What I found out is that the fuel pressure is a bit low. Measuring with a gauge it shows 3,2 bar. I have Markski software, 750cc injectors and std 3,8 bar FPR. I'm not sure if the fuel pump assembly is original but maybe it's time for a predictive maintenance? Unfortunately can't connect Durametric right now as my company laptop is not allowing installation

vtec_

Darn it! I still haven't gotten around to checking my fuel pressure either.

I came across an old post from @powdrhound and he and @CTS discovered that the stock FPR isnt really a 3.8 Bar FPR and its a bit lower. Not sure if this matters or not but perhaps an adjustable FPR that can precisely be dialed into 3.8 Bar would remedy this if it is indeed the problem?

powdrhound

Fuel pressure should be 3.8 with engine off and fuel pump running. With engine running at idle, vacuum will pull the fuel pressure down a bit. Can’t recall the exact value on a stock engine but it’s in the maintenance manual. If you are seeing 3.2-3.3 with engine at idle then you are fine.

Bernard IV

It misfires much more with Boostane octane boost I use. For sure something to do with it. My car runs like a dream on the stuff though.

Bernard IV

Siemens 60#

vtec_

Tested my FPR yesterday, my fuel pressure is runing 3.8 bar @ idle with the engine running and around 4 bar with the engine off and fuel pump relay turned on.

Don't think its the FPR thats causing the phantom idle. If I go on a short drive, it doesnt occur but if I drive it longer than 20 minutes it happens.