Joreysdad
Senior Member
- Joined
- May 10, 2006
- Messages
- 56
- Reaction score
- 0
- Your Mercedes
- 1998 w210 estate
Ok here goes, if you take the time to read this and can offer me a solution i may have to find you and kiss you, even if you have a beard!
I have an ML430, you may know this already. Since day one I have been having trouble, mainly around her running rough at startup and having a dead spot at 4000 rpm ish. She will also occasionally backfire in the exhaust if you push her to around 80 then let loose the throttle till she runs back to 60. Getting onto the motorway kinda stuff, or leaving the pillock in his corsa behind.
I had her converted to LPG, proper job no backstreet idiot, maclaren developed system for mercedes, and she runs a treat excepting for the dead spot at 4000 and occasional bang in the box.
This is the routine. Start her up, she's lumpy, try to pull away, she may missfire, particularly if you put engine under pressure and the shutdown feature for protection of cylinders cuts in (I had her de-catted thinking the problem lay in the blocked exhaust backing up the gases - she's better but not fixed), but if you keep your foot light till she's warm, as soon as she changes to gas all is ok, she runs fine. Ignoring the gas, if you leave her running on petrol she smoothes out and runs a treat, except for a dead spot at 4000 and occasional bang in box.
So the dead spot and bang in the box exist on both petrol and lpg, probably rules out the fuel pump, lpg doesn't have one.
I think I have the cold start problem licked. There is a fault p0410 showing which as you in the know will know is the secondary injection system. I'm working on it and with a bit of luck will sort the starting/running rough problem out when I find out which bit of the sis is acting up.
But the dead spot and bang in the box - what the hell is causing it!!!! ARRRRRGGGHHHH!!!!
In an attempt to sort out the rough running probs/dead spot and due to various traceable problems the car has been completely de-catted (the two large ones were knackered and had filled the back box up with broken down cat material), had a new back box, new mas (maf if you like), new o2 sensors all around, a couple of leads replaced and this morning new plugs (much to the discomfort of my hands and forearms this evening).
She is showing no faults at all except the p0410. Nothing, nada, nowt!!!!
I've always maintained that at 4000 rpm something happens. Not sure what and no-one to date has told me either way, but it seems that the car gets a boost of power. You feel it, dead spot, then kick up the ass here we go power all the way to 6000+. Past the dead spot the power is relentless.
But the dead spot is there - someone please please tell me why and how to fix it
PLEASE!!
I have an ML430, you may know this already. Since day one I have been having trouble, mainly around her running rough at startup and having a dead spot at 4000 rpm ish. She will also occasionally backfire in the exhaust if you push her to around 80 then let loose the throttle till she runs back to 60. Getting onto the motorway kinda stuff, or leaving the pillock in his corsa behind.
I had her converted to LPG, proper job no backstreet idiot, maclaren developed system for mercedes, and she runs a treat excepting for the dead spot at 4000 and occasional bang in the box.
This is the routine. Start her up, she's lumpy, try to pull away, she may missfire, particularly if you put engine under pressure and the shutdown feature for protection of cylinders cuts in (I had her de-catted thinking the problem lay in the blocked exhaust backing up the gases - she's better but not fixed), but if you keep your foot light till she's warm, as soon as she changes to gas all is ok, she runs fine. Ignoring the gas, if you leave her running on petrol she smoothes out and runs a treat, except for a dead spot at 4000 and occasional bang in box.
So the dead spot and bang in the box exist on both petrol and lpg, probably rules out the fuel pump, lpg doesn't have one.
I think I have the cold start problem licked. There is a fault p0410 showing which as you in the know will know is the secondary injection system. I'm working on it and with a bit of luck will sort the starting/running rough problem out when I find out which bit of the sis is acting up.
But the dead spot and bang in the box - what the hell is causing it!!!! ARRRRRGGGHHHH!!!!
In an attempt to sort out the rough running probs/dead spot and due to various traceable problems the car has been completely de-catted (the two large ones were knackered and had filled the back box up with broken down cat material), had a new back box, new mas (maf if you like), new o2 sensors all around, a couple of leads replaced and this morning new plugs (much to the discomfort of my hands and forearms this evening).
She is showing no faults at all except the p0410. Nothing, nada, nowt!!!!
I've always maintained that at 4000 rpm something happens. Not sure what and no-one to date has told me either way, but it seems that the car gets a boost of power. You feel it, dead spot, then kick up the ass here we go power all the way to 6000+. Past the dead spot the power is relentless.
But the dead spot is there - someone please please tell me why and how to fix it
PLEASE!!
