What is the actual fuel pressure and is it per the spec in the Volvo service manual? That said, low fuel pressure should cause problems on all cylinders, not just two cylinders. That certainly should have moved the problem except that you still had a badly fouled plug You can clean plug to an extent after theyre fouled. from 2/3 to 1/4 and the problem persisted.

As an observation, bad compression does not usually result in misfire symptoms, just an engine that has poor performance and can be rough if the cylinders are really bad. Author Topic: Cylinders not combusting, solved (Read 2263 times) 0 Members and 1 Guest are viewing this topic. I took this as a sign that when all were firing, the mix coming in was good.

Numbers 2 and three, a nice toasty tan color. If you have access to a compressed air supply you can try pressurizing the affected cylinders at TDC and then listen for air leaks which would be an indication of a HG problem, damaged valves or rings. I limped home and discovered the 1 and 4 cylinders had not been firing, their plugs black. If you have spark, then you need to review the compression test results to confirm the numbers. Injector for Cylinder 3 and 4 are not causing any change in RPM speed when commanded off using scan tool active tests option. If you have two permanently dead cylinders, I would first confirm that you have spark on those cylinders since you seem to be uncertain about that. How did you diagnose that the misfire is on cylinders 3 and 4 as opposed to being just a general misfire? The fact that the engine died and you had to tow the vehicle home, does that mean that you have now progressed from a misfire to two permanently dead cylinders and the engine does not run or you can get it to run but, badly? P0303 Explained - Cylinder 3 Misfire (Simple Fix) Watch on. This is what we call a rough idle, and a misfire is among the most common causes of a rough idle. Since the car is pre OBD II they generally do not have ECU misfire detection schemes. When there is a cylinder 3 misfire, the check engine light will frequently come on.

Cylinders 3 and 4 not combusting