944S sensor and oil/air seperator question
- Thread starter Dunners
- Start date
I thought I would update the thread just incase anybody is experiencing similar issues. It's a bit of a odd outcome, but the solution seems to be working.
As mentioned in my last post, since changing a few things on my 944 it's general running was getting worse and worse. I finally admitted defeat and just about hobbled the car to ProMax for them to have a look...
I asked them to check the basics and not to spend hours and hours trying to diagnose the problem. After checking vacuum leaks, intake leaks, all sensors and having swapped out the airflow metre for an alternative, they couldn't find anything particularly wrong nor was there any improvement to the car. However, after checking the pressure at the fuel rail they did say (at idle running pressure) it was slightly too high. I think the book says (someone might correct me on this) 3.3 bar - however mine was running a little too high at 3.8-4 bar. Andy did say this shouldn't really cause the running symptoms I'm experiencing, so as a last resort they swapped out the DME (ECU) for another known working one...
Now this is where things got a little odd. ProMax didn't have an 'S' version DME to try out, so they connected up an 'S2'. The moment they tried this and took the car for a spin, it was described as a complete transformation! Ok they thought, problem solved... the old DME must be knackered. So they proceeded to use the 'S2' DME and swap over the running chip from the 'S'.
Not so unfortunately - once everything was put back together the car continued to run as it once did, spluttering and misfiring all over the place. The next possible solution was to try one of their uprated chips to see if this was the issue - but no, absolutely no change, the car ran exactly the same. At this point they did say they were a bit miffed as to what could be causing the problem, so they popped the 'S2' chip back in and "bingo" the car ran beautifully again.
So this is were my car is now at. I got the car back yesterday with it running a 'S2' DME and it's never felt better. Mid-range torque is greatly improved, there is absolutely no hesitation in the throttle and top-end seems to be better as well. Over the next few weeks I'm going to work out what my MPG is doing and take it from there. As you're all obviously aware the engine maps are going to be slightly different, so it'll be interesting to see what I find. If the car starts to run worse then I was told to bring it straight back from them to have another look.
So there you go - a slightly odd outcome, but it seems to be working. If anybody can think why by running a 'S2' DME has answered all the car's running issues, then I'd be keen to know. I'm thinking it's to do with the FPR, and it causing the fuel to flow at a higher pressure at the rail. If my MPG turns out to be much, much worse then I think this is the next thing to try.
As said, any thoughts would be appreciated.
PS. the alloys were 'Veloce' I think. However, I've never seen another set like it as they only advertise split-rim items in the same design. Someone on here has them I think though, as the car was put back to standard once it was sold.
Thanks again.
Drew
As mentioned in my last post, since changing a few things on my 944 it's general running was getting worse and worse. I finally admitted defeat and just about hobbled the car to ProMax for them to have a look...
I asked them to check the basics and not to spend hours and hours trying to diagnose the problem. After checking vacuum leaks, intake leaks, all sensors and having swapped out the airflow metre for an alternative, they couldn't find anything particularly wrong nor was there any improvement to the car. However, after checking the pressure at the fuel rail they did say (at idle running pressure) it was slightly too high. I think the book says (someone might correct me on this) 3.3 bar - however mine was running a little too high at 3.8-4 bar. Andy did say this shouldn't really cause the running symptoms I'm experiencing, so as a last resort they swapped out the DME (ECU) for another known working one...
Now this is where things got a little odd. ProMax didn't have an 'S' version DME to try out, so they connected up an 'S2'. The moment they tried this and took the car for a spin, it was described as a complete transformation! Ok they thought, problem solved... the old DME must be knackered. So they proceeded to use the 'S2' DME and swap over the running chip from the 'S'.
Not so unfortunately - once everything was put back together the car continued to run as it once did, spluttering and misfiring all over the place. The next possible solution was to try one of their uprated chips to see if this was the issue - but no, absolutely no change, the car ran exactly the same. At this point they did say they were a bit miffed as to what could be causing the problem, so they popped the 'S2' chip back in and "bingo" the car ran beautifully again.
So this is were my car is now at. I got the car back yesterday with it running a 'S2' DME and it's never felt better. Mid-range torque is greatly improved, there is absolutely no hesitation in the throttle and top-end seems to be better as well. Over the next few weeks I'm going to work out what my MPG is doing and take it from there. As you're all obviously aware the engine maps are going to be slightly different, so it'll be interesting to see what I find. If the car starts to run worse then I was told to bring it straight back from them to have another look.
So there you go - a slightly odd outcome, but it seems to be working. If anybody can think why by running a 'S2' DME has answered all the car's running issues, then I'd be keen to know. I'm thinking it's to do with the FPR, and it causing the fuel to flow at a higher pressure at the rail. If my MPG turns out to be much, much worse then I think this is the next thing to try.
As said, any thoughts would be appreciated.
PS. the alloys were 'Veloce' I think. However, I've never seen another set like it as they only advertise split-rim items in the same design. Someone on here has them I think though, as the car was put back to standard once it was sold.
Thanks again.
Drew
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