Running problems

[adz87kc]

Hey guys, i have a problem with my car and to be honest i don't know what to do.

Driving the car normally, sat at idle, and starting the car is all fine.
Driving on the low boost setting on my EBC (0.8bar) the car drives fine also maybe a little rich? -between 10.5:1 and 11.5 on my AFR gauge.

But when I use the high boost setting (1.1bar) the car doesn't drive great at all. Feels like its holding back big time and it leans out to around 13.5:1 and it misfired bad the other day too.
Needless to say high boost is no longer used.

I've checked the plugs, the coilpacks, and checked for obvious pipe leaks but to no avail.
The engine hasn't been modified since the remap either.

Was thinking a boost leak at first but would a leak not cause it to run rich rather than lean as the metered air would be escaping regardless of what pressure it was running?

Any ideas?

 

[Jay]

afm? it could have crap on the sensor, or have a dodgy wire

 

[Auss15]

Sounds like the AFR's are out in the higher boost /RPM parameters. I would check the tune before you go to far.

 

[adz87kc]

afm? it could have crap on the sensor, or have a dodgy wire

i'll get some carb cleaner and give the element a spray and i'll check the wires on the plug for anything suspect.

Sounds like the AFR's are out in the higher boost /RPM parameters. I would check the tune before you go to far.

What do you mean by that? Have the guy who mapped the Nistune board go over the air fuel map again?

 

[Auss15]

What do you mean by that? Have the guy who mapped the Nistune board go over the air fuel map again?

Yes, if it's leaning out in the higher RPM its not getting enough fuel. Have you checked your flow rate. Do you have the stock fuel pump and FPR by chance?

 

[adz87kc]

Yes, if it's leaning out in the higher RPM its not getting enough fuel. Have you checked your flow rate. Do you have the stock fuel pump and FPR by chance?

A mate of mine has a consult diagnostic program and lead so i'll check the injector duty with that. I have a 255LPH fuel pump but the regulator is stock.

 

[Auss15]

BTW don't use carby cleaner on the AFM sensor,use an Electronic solvent cleaner

 

[LuPix_S15]

Fuel regulator should never been an issue for mild upgrades... FPR is a bit overkill and not required for most applications so don't worry about that.

Like Auss says it's best to have a word with whoever mapped your car in the first instance and go from there...

It doesn't sound like boost leak cos you won't be able to hold high boost if that was the case.

 

[adz87kc]

Cleaned the two wires in the MAF sensor today and the car drives as it should again!
It running rich 11:1 but thankfully it was an easy fix.

Thanks guys

A win in my book

 

[Jay]

nice one, easy fix is always welcome. any probs to do with fueling i would always go to the maf first. its easy and cheap to check, even for a compete novice with the spanners. happy driving!!

 

[adz87kc]

Thread revival . . .

A couple of months on and this issue keeps occurring. Whilst it seemed to be fixed 100% when i cleaned with carb cleaner the first time, the problem keeps happening.

I've borrowed a friends MAF from his 14a and it run great to his house (under heavy load) but from there to my place it was running like a bag of spanners on high boost again but low boost and easy driving were fine.
Super stumped now

 

[JaseYpk]

probably an obvious here - but i'm assuming your air filter is filtering properly and hasnt got an holes or just mega old and ragged, thus letting crap through to the sensor after a few miles?

 

[martinbattye]

Hey guys, i have a problem with my car and to be honest i don't know what to do.

Driving the car normally, sat at idle, and starting the car is all fine.
Driving on the low boost setting on my EBC (0.8bar) the car drives fine also maybe a little rich? -between 10.5:1 and 11.5 on my AFR gauge.

But when I use the high boost setting (1.1bar) the car doesn't drive great at all. Feels like its holding back big time and it leans out to around 13.5:1 and it misfired bad the other day too.
Needless to say high boost is no longer used.

I've checked the plugs, the coilpacks, and checked for obvious pipe leaks but to no avail.
The engine hasn't been modified since the remap either.

Was thinking a boost leak at first but would a leak not cause it to run rich rather than lean as the metered air would be escaping regardless of what pressure it was running?

Any ideas?

i would be checking fuel pump, system pressure etc..

although a walbro will fuel way over what your running..

the fact that its running so pig rich on low boost and then lean on only .3bar more is a little worrying.

a spark misfire will give you a lean reading AFR. so firstly try plugs.

check for air leaks around maf etc..

a boost leak is not an issue here. (causes rich AF)

 

[martinbattye]

also im pretty sure the AFM is well and truely maxxed out at 1.1bar.. so thats not really helping things.