Surrey rolling road day

[Fusion Ed]

The point that I can't understand though is that when checking the ecu map, when I loaded the car up in 3rd, the engine went right off the fuel and ignition load scales, that the OE ecu uses.

Its probably more simple if you break the problem down. You have two separate issues here which are both contributing to the problem.

Firstly your going beyond the stock map, many people do this, in fact anyone running your boost or more on stock setup will be going off the map. Its not always a problem if you don't go too FAR from the map, but in some cases it can be, and in every case it means the ecu is having to calculate the value from the last known cell it was in + correction factors applied.

Secondly your fuel pressure appears consistently low, which points to a base pressure problem.

Both of these above problems are causing the unusual lean problem you have. If you find a base pressure problem, and fix it you may find all is well, even given the fact that the ecu goes off the map. (Although its not ideal)

 

[youngsyp]

Its probably more simple if you break the problem down. You have two separate issues here which are both contributing to the problem.

Firstly your going beyond the stock map, many people do this, in fact anyone running your boost or more on stock setup will be going off the map. Its not always a problem if you don't go too FAR from the map, but in some cases it can be, and in every case it means the ecu is having to calculate the value from the last known cell it was in + correction factors applied.

Secondly your fuel pressure appears consistently low, which points to a base pressure problem.

Both of these above problems are causing the unusual lean problem you have. If you find a base pressure problem, and fix it you may find all is well, even given the fact that the ecu goes off the map. (Although its not ideal)

Thanks Ed, that makes sense to me now.

It seems that I've ruled out the fuel filter. I took it off last night and the un-filtered fuel was a little dirty but, the filter was in no way blocked.

I also took the MAF apart and that was dirty (black build up of dust and grime), on the trailing edge of the elements. It was easy to clean off though !

I have a 255 lph Walbro pump on order and will install it as soon as it arrives. I'll replace the fuel filter, at the same time, as a matter of course !

Interestingly enough, after dropping the boost back down to 1 bar peak pressure, there doesn't seem to be any difference in how the car performs ?!

 

[Fusion Ed]

dropping 0.1 bar (5%) is alone often not enough to be noticed, however if the AFR's are better power would increase, possibly making the same/similar power as you were before. I suspect afrs would be the same however.

 

[micra_pete]

Sorry for jumping in

youngsyp - am i reading right that you are using "conzult" to monitor map tracing on the stock ecu?

if so you will always end up in the far right of the ecu load scale on just about any nissan at full load, its just the way nissan set up their ecus

what you need to do is monitor the tp (load) address seperately, and see how much higher than stock you are.

Sorry if i mis-understood the posts

 

[youngsyp]

Sorry for jumping in

youngsyp - am i reading right that you are using "conzult" to monitor map tracing on the stock ecu?

if so you will always end up in the far right of the ecu load scale on just about any nissan at full load, its just the way nissan set up their ecus

what you need to do is monitor the tp (load) address seperately, and see how much higher than stock you are.

Sorry if i mis-understood the posts

It was 'Conzult' used to monitor map tracing, yes !

Thanks for the other info too ! ;-)

 

[micra_pete]

no problem

 

[Fusion Ed]

Pete is correct, I should be more clear however that it was obvious in this case it was excessive. You wouldn't deliberately scale a map to have unused cells, as that simply wastes additional mapping space, but in this case the cells were reached some time before max engine load was reached.

n.b. pete I was the one demonstrating this to youngsyp.

 

[youngsyp]

n.b. pete I was the one demonstrating this to youngsyp.

Sorry, I should have mentioned that !

 

[youngsyp]

what you need to do is monitor the tp (load) address seperately, and see how much higher than stock you are.

I've just read through this again and wondered if you could ellaborate on this statement at all ?

By 'tp', I take it you mean throttle position ?!

Cheers

Paul

 

[micra_pete]

no, sorry, tp isn't throttle position, its the load value calulated on the nissan ecu, ie the number in the load scale

 

[youngsyp]

no, sorry, tp isn't throttle position, its the load value calulated on the nissan ecu, ie the number in the load scale

Ok. So how could this 'load address' be 'monitored separately' Pete ?

 

[micra_pete]

if you know the address on the ecu where the value is stored it can be monitored with a simple serial programme, datascan, etc.

its not that simple tbh, however, but it can be done.

in datascan its easy as you have an address monitor tool

but you still need to know the address - this takes some searching through the code.

ed has some very nice software he should be able to do it in too

 

[youngsyp]

if you know the address on the ecu where the value is stored it can be monitored with a simple serial programme, datascan, etc.

its not that simple tbh, however, but it can be done.

in datascan its easy as you have an address monitor tool

but you still need to know the address - this takes some searching through the code.

ed has some very nice software he should be able to do it in too

Thanks Pete. ;-)