Advancedme
Junior Member
- Messages
- 18
Recently I noticed a misfire at idle, just a single misfire once every few seconds at idle. When ever I revved the engine it ran clean on all 8.
However driving the car later it started misfiring and losing power accross the cylinders. I limped the car home and turned it off.
When I came back to it the start up was perfect and after a few seconds a tiny misfire started. 30 seconds later it was struggling to run at all.
I replaced the MAF sensor with a new one and found no improvement. I removed all of the plugs and burned them clean. Refitted the plugs fired it up and for a moment believed it was fixed. It wasn't.
I checked o2 readings and at idle with the slight miss all trims were uniform and post cat sensors were cycling up and down.
I then fitted fuel pressure gauges to the shraeder valves on the the fuel rails. I removed the valve and then used -4 aeroquip fittings to connect to gauges. I strongly believed a fuel pump was dying but when the heavy misfiring and popping occurred both rails had perfect 45psi of fuel. The both also pump up to that immediately so I am satisfied it's not the pumps.
Next thing I checked were the injectors.
I found two with poor spray pattern on one side and these were down 3% & 5% on flow also. See photo.
Tried cleaning them ultrasonically but to no avail. Luckily I found some second hand on eBay and when put with my other 6 I have a set of 8 within 1% of each other!
Surely this has to fix it right? Nope
Runs smoother but after a few seconds the little misfire comes back.
I've ordered a couple of coils and new spark plugs and hope it's a cool pack... But quite odd symptoms for me.
Question to you guys. Had any ever had any issues with the EGR valves sticking? It reminds me of an issue I once had with a Honda. Anyone have any experience with the EGR on this engine?
Many thanks
However driving the car later it started misfiring and losing power accross the cylinders. I limped the car home and turned it off.
When I came back to it the start up was perfect and after a few seconds a tiny misfire started. 30 seconds later it was struggling to run at all.
I replaced the MAF sensor with a new one and found no improvement. I removed all of the plugs and burned them clean. Refitted the plugs fired it up and for a moment believed it was fixed. It wasn't.
I checked o2 readings and at idle with the slight miss all trims were uniform and post cat sensors were cycling up and down.
I then fitted fuel pressure gauges to the shraeder valves on the the fuel rails. I removed the valve and then used -4 aeroquip fittings to connect to gauges. I strongly believed a fuel pump was dying but when the heavy misfiring and popping occurred both rails had perfect 45psi of fuel. The both also pump up to that immediately so I am satisfied it's not the pumps.
Next thing I checked were the injectors.
I found two with poor spray pattern on one side and these were down 3% & 5% on flow also. See photo.
Tried cleaning them ultrasonically but to no avail. Luckily I found some second hand on eBay and when put with my other 6 I have a set of 8 within 1% of each other!
Surely this has to fix it right? Nope
Runs smoother but after a few seconds the little misfire comes back.
I've ordered a couple of coils and new spark plugs and hope it's a cool pack... But quite odd symptoms for me.
Question to you guys. Had any ever had any issues with the EGR valves sticking? It reminds me of an issue I once had with a Honda. Anyone have any experience with the EGR on this engine?
Many thanks