Just about had enough!
Discussion
I posted a few weeks back about a recurring engine fault that after 100 miles the engine in my 98 4.5 begins to run 'lumpy' and cut out at idle.
This has continued and its now back in for its 5th visit in 2 months. Lots of head scratching on everybodys part so over to you guys.
Here's the history:
Car running well and went in for a 12k service including valve adjustments - 200 miles later lumpy.
In for reset - 150 miles later lumpy.
Repeat 3 times - throw in new lambda sensor, new throttle pots, check of throttle linkage/spindles, reprogrammed ecu, hours and hours of diagnostics - 100 miles later lumpy.
Lumpy = at low revs when I floor it nothing but very slow rev rise to c 3k rpm then, whoosh, all back to normal. Pulling up at lights/jct revs drop and engine cuts out.
Le Mans soon so I really need your help else its will be a very dull drive down in a Merc estate!!
What would you do?
S.
This has continued and its now back in for its 5th visit in 2 months. Lots of head scratching on everybodys part so over to you guys.
Here's the history:
Car running well and went in for a 12k service including valve adjustments - 200 miles later lumpy.
In for reset - 150 miles later lumpy.
Repeat 3 times - throw in new lambda sensor, new throttle pots, check of throttle linkage/spindles, reprogrammed ecu, hours and hours of diagnostics - 100 miles later lumpy.
Lumpy = at low revs when I floor it nothing but very slow rev rise to c 3k rpm then, whoosh, all back to normal. Pulling up at lights/jct revs drop and engine cuts out.
Le Mans soon so I really need your help else its will be a very dull drive down in a Merc estate!!
What would you do?
S.
what's the trend on the adaptive trimming? .. can u find out at all from teh dealer? .. at 3k ish the ecu blends the adaptive trimmed map back into the base map, sounds curious that it's at this point that the car starts to run right again ..
edited to add .. have you been using the air conditioning since the service where maybe you wren't using it before?
>> Edited by joospeed on Monday 24th May 13:33
edited to add .. have you been using the air conditioning since the service where maybe you wren't using it before?
>> Edited by joospeed on Monday 24th May 13:33
could it be over fuelling?
the tuscan had a dodgy temp sensor which thought engine was always cold so dumped massive amounts of fuel in.
could be something to do with fuelling maybe too much or not enough? could be a dodgy sensor somewhere? does the engine work on manifold pressure and/or throttle position? if it's manifold pressure could there be a crack in a manifold?
some of the guys like jools will know but there might be a 'safe' setting on the ecu which might be kicking in? (that's a total guess! so don't shoot me down if there isn't!! )
the tuscan had a dodgy temp sensor which thought engine was always cold so dumped massive amounts of fuel in.
could be something to do with fuelling maybe too much or not enough? could be a dodgy sensor somewhere? does the engine work on manifold pressure and/or throttle position? if it's manifold pressure could there be a crack in a manifold?
some of the guys like jools will know but there might be a 'safe' setting on the ecu which might be kicking in? (that's a total guess! so don't shoot me down if there isn't!! )
Christ!, 5 visits in 2 months, get it to someone who knows how to set a cerb up properly. The diagnostics should help find the fault/point you in the right direction, but not if they have a muppet operating it.
There are soooo many possibles with these engines, you could throw a fortune in parts at it & still have the problem.
I would imagine you have looked at the leads, coils, plugs, checked the connectors on the injectors & ecu, crank sensor, big fuse, all the earthing points.
Get it up to Jools, a long way to go, but i've a feeling you will save more than you'll spend.
Darren.
There are soooo many possibles with these engines, you could throw a fortune in parts at it & still have the problem.
I would imagine you have looked at the leads, coils, plugs, checked the connectors on the injectors & ecu, crank sensor, big fuse, all the earthing points.
Get it up to Jools, a long way to go, but i've a feeling you will save more than you'll spend.
Darren.
Agree totally with the above comments.
i.e. get the car to Joolz or Austec. I know it sounds like a long drive but it should be worth it.
My car is/was* running sweet and they two guys are the only ones who have worked on it.
* it's in the body shop since mid april so I hope it still runs ok.
i.e. get the car to Joolz or Austec. I know it sounds like a long drive but it should be worth it.
My car is/was* running sweet and they two guys are the only ones who have worked on it.
* it's in the body shop since mid april so I hope it still runs ok.
I had a problem like that after my car was last serviced about 10 months ago. It ran like shit like yours for about a week then cleared up without anyone even touching anything!
But it done it again the other week after a wash. Got the WD40 out, done my connections and after a short run she was back to her normal self!
Billy.
But it done it again the other week after a wash. Got the WD40 out, done my connections and after a short run she was back to her normal self!
Billy.
Disconnecting the ecu and reconnecting does not reset the maps. It just starts the unit on a new set of updates to the maps and can temporarily appear to sort the problem. I'm intrigued that the MIL light is not flashing. If you have access to the software, see if there is any history (it records previous errors/out of range readings)
Had a rough running problem myself, which dealers had, according to the records, fixed at least 3 times. After speaking to Jools, turned out the connectors for the lambda sensors that lie on top of the gearbox had corroded (fills up with water!!!). Cleaned them up and added some electrogrease to seal against the weather and, over 4000 miles later, not a peep. Take it to Jools, you know it makes sense.
Had a rough running problem myself, which dealers had, according to the records, fixed at least 3 times. After speaking to Jools, turned out the connectors for the lambda sensors that lie on top of the gearbox had corroded (fills up with water!!!). Cleaned them up and added some electrogrease to seal against the weather and, over 4000 miles later, not a peep. Take it to Jools, you know it makes sense.
suffolkfox said:
Disconnecting the ecu and reconnecting does not reset the maps. It just starts the unit on a new set of updates to the maps and can temporarily appear to sort the problem. I'm intrigued that the MIL light is not flashing. If you have access to the software, see if there is any history (it records previous errors/out of range readings)
Had a rough running problem myself, which dealers had, according to the records, fixed at least 3 times. After speaking to Jools, turned out the connectors for the lambda sensors that lie on top of the gearbox had corroded (fills up with water!!!). Cleaned them up and added some electrogrease to seal against the weather and, over 4000 miles later, not a peep. Take it to Jools, you know it makes sense.
like I said it worked for me over a year ago. that was the most simple thing to do before it would have to go in to the workshop and have mechanic,s work on it , must have been lucky
Just a little happy now. Got my car back - not wanting to tempt fate but I have done a few miles and it drives like an absolute dream - all sorted I hope.
I couldn't quite believe it but the problem went like this.
Car comes back from dealer running smoothe. I go for test run all fine. Get excited about having the car back so I give it a good old wash and polish - next run lumpy.
It turns out that some how water was getting onto the loom and running into the ECU. ECU has been dried out and sealed a bit better - end of problem. Can't believe that something so simple could cause such hassle (4 return trips to the dealer)
Lets hope its now sorted for Le Mans.
S.
I couldn't quite believe it but the problem went like this.
Car comes back from dealer running smoothe. I go for test run all fine. Get excited about having the car back so I give it a good old wash and polish - next run lumpy.
It turns out that some how water was getting onto the loom and running into the ECU. ECU has been dried out and sealed a bit better - end of problem. Can't believe that something so simple could cause such hassle (4 return trips to the dealer)
Lets hope its now sorted for Le Mans.
S.
Gassing Station | Cerbera | Top of Page | What's New | My Stuff