Fueling problem?
Discussion
I'm still on the hunt to detemine the cause of my break down before Christmas but I now think it is a fueling problem.
Last month I completely checked all the common electric failings; corroded fuses/relays, feed to the ecu etc. all appears to be fine. I then moved onto to fitting the new fuel pump (044) I was supplied with the exhaust. I noticed the fuel pipe from the filter to the pump had a slight kink as it left the filter so thought it might be collapsing. The new longer tail on the fed to the pump enabled me to cut off the suspect piece of pipe and still maintain a smooth radius. I also replaced the fuel filter.
For 2 weeks after completing this work the car (3R) has driven fine, not a sign of a misfire. This past week however, the misfire is back! Not long after starting it, and driving it for a couple of minutes if I'm at traffic lights, the idle starts to get rough and I'm pretty certain the pump appears to get noisier - almost as though it is struggling. Weirdly pulling away, the misfire almost instantly goes and for the rest of the journey its fine. The only slight difference to this was at the weekend but I had been idling poorly for approximately 5 minutes, and when I pulled away it was almost as though a rev limiter had kicked in and I couldn't rev past 3500 rpm, soon after it cleared and all was good again!
Reading a lot of various articles on the forums I am now suspecting the fed pipe from the tank to the filter, what do you think? Could this behaviour be caused by the breather pipe blocked? Or should I be checking something else?
I would really like to rule out the lot and replace both the tank to filter pipe and the filter to pump, are there any recommendations? Can I get rid of the loop completely? What parts are required and where can I get them?
Any help would be appreciated,
Mat
Last month I completely checked all the common electric failings; corroded fuses/relays, feed to the ecu etc. all appears to be fine. I then moved onto to fitting the new fuel pump (044) I was supplied with the exhaust. I noticed the fuel pipe from the filter to the pump had a slight kink as it left the filter so thought it might be collapsing. The new longer tail on the fed to the pump enabled me to cut off the suspect piece of pipe and still maintain a smooth radius. I also replaced the fuel filter.
For 2 weeks after completing this work the car (3R) has driven fine, not a sign of a misfire. This past week however, the misfire is back! Not long after starting it, and driving it for a couple of minutes if I'm at traffic lights, the idle starts to get rough and I'm pretty certain the pump appears to get noisier - almost as though it is struggling. Weirdly pulling away, the misfire almost instantly goes and for the rest of the journey its fine. The only slight difference to this was at the weekend but I had been idling poorly for approximately 5 minutes, and when I pulled away it was almost as though a rev limiter had kicked in and I couldn't rev past 3500 rpm, soon after it cleared and all was good again!
Reading a lot of various articles on the forums I am now suspecting the fed pipe from the tank to the filter, what do you think? Could this behaviour be caused by the breather pipe blocked? Or should I be checking something else?
I would really like to rule out the lot and replace both the tank to filter pipe and the filter to pump, are there any recommendations? Can I get rid of the loop completely? What parts are required and where can I get them?
Any help would be appreciated,
Mat
You checked the anti-rollover valve? As you say could be the vacuum being created, but when it gets too big it finally overcomes a sticking/blocked valve.
Easy way to check that is just drive around with low fuel and the fuel cap left in but loose. If that fixes it then indeed you have a breathing problem.
Easy way to check that is just drive around with low fuel and the fuel cap left in but loose. If that fixes it then indeed you have a breathing problem.
Hi Matt , I get all my fuel pipe ect from Earls and to be honest it's a pretty cheap mod to change the pipe so I would do it just for piece of mind .
When you get the lumpy idle take it in turns to pull off one at a time the ecu feed to the coils to see if you get a change in engine sound , could be a faulty coil breaking down when it get warm . The front bank number 5pr6 can give. Issues as it sits close to the front oil feed .
What's the plug colour like and exhaust tips are they sooty ? All these things can tell you what's going on .
You could also try resetting the ECU adaptive maps just disconnect battery for 5 mins the reconnect and go for a drive .
As Joust suggest check roll over , I fitted a positive pressure unit to help pump .
Hope this helps Tux
When you get the lumpy idle take it in turns to pull off one at a time the ecu feed to the coils to see if you get a change in engine sound , could be a faulty coil breaking down when it get warm . The front bank number 5pr6 can give. Issues as it sits close to the front oil feed .
What's the plug colour like and exhaust tips are they sooty ? All these things can tell you what's going on .
You could also try resetting the ECU adaptive maps just disconnect battery for 5 mins the reconnect and go for a drive .
As Joust suggest check roll over , I fitted a positive pressure unit to help pump .
Hope this helps Tux
I have checked the plugs and they are fine and the exhaust isn't too sooty. The coilpack idea is a good one and I was going to do that, the difficulty is being able to do it when the car has the fault. Typically if I just start the car in the drive it won't misbehave!
Does anyone know what diameter and type of fuel pipe I need to order? - I'm being a bit lazy and trying to avoid removing the wheel, cover and then measuring it
(I use the car daily)
How difficult is it to get to the fuel tank outlet, do I need to remove the undertray etc?
I'll certainly check the ARV or at least try the fuel cap trick - Tux, have you got the part number of the item you replaced it with?
Mat
Does anyone know what diameter and type of fuel pipe I need to order? - I'm being a bit lazy and trying to avoid removing the wheel, cover and then measuring it
(I use the car daily)How difficult is it to get to the fuel tank outlet, do I need to remove the undertray etc?
I'll certainly check the ARV or at least try the fuel cap trick - Tux, have you got the part number of the item you replaced it with?
Mat
Edited by mlarj on Thursday 7th February 12:23
Edited by mlarj on Thursday 7th February 12:25
Quick update: I decided to remove the breather pipe from the neck of the filler after the suggestions last week, since then there has been no sign of the misfire and the car appears to be a lot smoother at low rpm - hopefully it will stay this way...famous last words!
15mm fuel pipe, I'm guessing that must be the internal diameter?
Mat
15mm fuel pipe, I'm guessing that must be the internal diameter?
Mat
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