AAN serious Maf trouble..

[prj]

Btw, if there is a heavy leak somewhere in one of the vacuum hoses, that connect to the FPR, you can flood the engine as well, because fuel pressure will go up at idle.

Check all these things.

[pasbogdan]

I had something like this before.If i pushed the throttle smooth i could rew it to 3000 rmp.If i got on boost side i got instant limp mode.Seems to me like a masive leak.
My problem was a 3 cm crack on the turbo to intercooler pipe.
I know this seems to simpple,but i had another one:
Map sensor error.After cecking n75,thinking of removing the wastegate i found the hose going from intake manifold to ecu NOT conected to moisture trap.
So..Get to a boost test of your sistem.

[quattrojan]

The best way is on a special ultrasound washing stand for injectors.

http://www.youtube.com/watch?v=ZJmdvoZ83hY

How are you adjusting fuel pressure? If it's some cheap chinese adjustable FPR - I had very much trouble with them before.

The MAF signal - maybe not the MAF is bad, but the connector?
Try measuring the voltage from the MAF at different stages.

got a drop-in adjustable fpr from 034 that i hope is of good quality?

Measuring the maf, well.. now i'm on thin ice....

The wires coming from the car to the maf, can i measure each of those (with maf disconnected) and what will the different coloured wire show? (if possible)

and how to measure the maf would be interesting to know as i kinda hate electrics...

hehe

[prj]

a) Checked
Any easy way to check the injectors? just taking the whole fuelrail with injectors out and se how the spray? with pos disconnected..

The best way is on a special ultrasound washing stand for injectors.

http://www.youtube.com/watch?v=ZJmdvoZ83hY

How are you adjusting fuel pressure? If it's some cheap chinese adjustable FPR - I had very much trouble with them before.

The MAF signal - maybe not the MAF is bad, but the connector?
Try measuring the voltage from the MAF at different stages.

[quattrojan]

Hm, is the connection to the FPR alright?
You don't have an issue with a leaky injector?

Car running rich on idle:
a) O2 sensor stuck on lean
b) Incorrect fuel pressure
c) Incorrect MAF signal/bad MAF
d) Injector(s) stuck

I don't think there can be anything else if it worked properly before.
Any kind of holes or leaks in the intake would make it go lean on idle, not rich, because it would suck in extra air that does not go through the MAF.
Misfire will always show lean as well (O2 not used).

a) Checked
b) same as before, so hopefully that shouldn't be the problem
c) 3 different mafs giv the same result (tested fine on other aan cars)
d) Only thing i've tried is to disconnect on at a time when the idling and there where difference. But if one or two isn't closing propperly that might cause some serious problem?

Any easy way to check the injectors? just taking the whole fuelrail with injectors out and se how the spray? with pos disconnected..

[prj]

Hm, is the connection to the FPR alright?
You don't have an issue with a leaky injector?

Car running rich on idle:
a) O2 sensor stuck on lean
b) Incorrect fuel pressure
c) Incorrect MAF signal/bad MAF
d) Injector(s) stuck

I don't think there can be anything else if it worked properly before.
Any kind of holes or leaks in the intake would make it go lean on idle, not rich, because it would suck in extra air that does not go through the MAF.
Misfire will always show lean as well (O2 not used).

[quattrojan]

The fuel pressure... you said it is 4.5 bar at idle.
Are you sure your car is supposed to run with 5 bar fuel pressure?

AFR should be 14.7 at idle...
Try disconnecting the O2 sensor, maybe it's stuck on lean.

When the car was finished we estimated 4,54 bar for fuel preasure was the right amount, and thats the way its been all the time and working well (nice afr numbers),

I did disconnect the 02, even swapped it with a brand new oem one i had lying around. No difference..

[Thuppu]

This thread and chat is very interesting. Please, go on...

[prj]

Well, because sadly that's basically what MRC charge for a live mapping session...

Well, if it's done on the dyno, then it makes sense.
Dynos are expensive, and dyno time is expensive.
Even if you get a standalone, dyno time will still run 70gbp+ per hour.

[LHD_Kid]

600 gbp? For that I can fly to any point in europe, map the car and fly back...
Why would you pay 600gbp for a remap when you can buy and fit a standalone for that money?

Well, because sadly that's basically what MRC charge for a live mapping session...

[prj]

The fuel pressure... you said it is 4.5 bar at idle.
Are you sure your car is supposed to run with 5 bar fuel pressure?

AFR should be 14.7 at idle...
Try disconnecting the O2 sensor, maybe it's stuck on lean.

[quattrojan]

Have gone over all the things i can think of today and all seems fine. even got a another WORKING maf (nr 4...) and still the car is acting like a hooker on crack! So there cant be anything wrong with the maf from what i can se.. When maf plugged in i get a whopping 8,5-9,5 AFR at idle... idling is still in the range of 400-1500 rpms. When reving it seems to kinda missfire and is very rough..

The second i disconnect the maf, reving and idling is just like its a brand new car. AFR in the range of 11,8-12,5

I Think my neighbours almost called the fire station earlier cause all the black smoke

[prj]

Anywhere i can get a plug and play kit for that price? By that i mean really plug and play(pray?). would prefer not to spend time changing alot of sensor and doing alot of custom stuff to get them in the right position

Well, VEMS PnP is just 120-130 eur more than 600gbp.
You'll have to map it though

[quattrojan]

600 gbp? For that I can fly to any point in europe, map the car and fly back...
Why would you pay 600gbp for a remap when you can buy and fit a standalone for that money?

Anywhere i can get a plug and play kit for that price? By that i mean really plug and play(pray?). would prefer not to spend time changing alot of sensor and doing alot of custom stuff to get them in the right position

[prj]

I am 99% sure Doug has the standard maf and I am sure Jp will confirm this

Well, then that's just not good, because standard MAF maxes out at about 5.7 volts even with the RS2 turbo.
When you are mapping to the last cell, then as you traverse that cell on spoolup, your fueling goes rich and then it leans up again. Same with timing.
It's possible to make it work - and it does work on full throttle, but you are in essence not using the MAF at all on high load.
That way you can't leave the fuel cut limiter in tact either.

You see, Motronic can work even without a MAF. It has an Alpha-N system as fallback. But that system can never be very precise. Same as mapping after the MAF has maxed out. You can do it, but the ECU is essentially blind after a certain point and uses the same injector latency time and timing for every condition after that point.
It's essentially the same as what happens in a speed density system when maxing out the MAP sensor and then just enriching the last cell / retarding timing in the last cell (or column/row) on the timing map.
I am sure any VEMS user will tell you why that is not good. It will work, but it's just not the way to do it.

Well I've payd for the new maf £90 but the trouble with the new maf is the remap.This it is gonna be expensive .It is easy for you because your are in the bussines but for others it is not as easy.A remap it is £600 and if you already paid another many hundreds for curent setup it is not cheap at all

600 gbp? For that I can fly to any point in europe, map the car and fly back...
Why would you pay 600gbp for a remap when you can buy and fit a standalone for that money?