too much fuel, i think!!

G

gtirpower

New Member
basically my R has recently started to this:

when i started the car one morning, it started fine but the revs dropped straight away below 1k rev and puffs of black smoke from the exhaust (car has front exit exhaust) so took the plugs out and checked them and they were black but not burnt so just wiped them down and put them back in and same thing straight away they went black again, have drove the car it still boost well and drives ok but it smokes lightly with black smoke.

there is strong smell of petrol so all i could think was its burning to much fuel.

i have checked for any leaks but everything seems ok, the car was fine just parked it up and started it after about a week and it started doing this.

the car has AEM stand alone ecu with evo injectors fitted and welbro 255 pump.

what could it possibly be??
 
R

RU55 GTR

Member
Hi,

Sounds like fuelling to me with the info you have supplied. An addittional sign to look for is popping/back-firing from the exhaust as you come off the loud pedal. However, some cars do this anyway due to set-up.

The culprits I'd check are lambda/o2 sensor and AFM. I trust that the AEM stand alone ECU still utlises these to control fuelling?

Has your oil become saturated with fuel i.e. does it smell of fuel? If it does, I suggest you don't drive hard or boost the car much as this oil will not be protecting your internals! I suggest you change your oil soon or atleast as soon as you have rectified the issue.

Best of luck and keep us updated please!
 
PobodY

PobodY

Moderators
Staff member
Have you fiddled with anything?

Does the AEM have a diagnostic mode; I'd be checking to see if it has logged any faults.

I suspect it's going to be your lambda sensor (i.e. the closed-loop mixture is out) but I don't know anything about the AEM system.
 
G

gtirpower

New Member
RU55 GTR said:
Hi,

Sounds like fuelling to me with the info you have supplied. An addittional sign to look for is popping/back-firing from the exhaust as you come off the loud pedal. However, some cars do this anyway due to set-up.

The culprits I'd check are lambda/o2 sensor and AFM. I trust that the AEM stand alone ECU still utlises these to control fuelling?

Has your oil become saturated with fuel i.e. does it smell of fuel? If it does, I suggest you don't drive hard or boost the car much as this oil will not be protecting your internals! I suggest you change your oil soon or atleast as soon as you have rectified the issue.

Best of luck and keep us updated please!
Click to expand...
ok i will get the lambda sensor checked out, what is AFM?? i have no idea if the ecu utlises the fuelling.

i will check the oil later on and keep you updated

thanks for the help
 
G

gtirpower

New Member
PobodY said:
Have you fiddled with anything?

Does the AEM have a diagnostic mode; I'd be checking to see if it has logged any faults.

I suspect it's going to be your lambda sensor (i.e. the closed-loop mixture is out) but I don't know anything about the AEM system.
Click to expand...
the only thing i ever fiddled with is taking the intake pipe of the turbo just to check the turbo and that's about it, i think the AEM does have a diagnostic and i will be getting this checkd out soon.
 
PobodY

PobodY

Moderators
Staff member
The AEM might actually use a MAP sensor rather than a MAF. - I'm pretty sure that was one of the selling points.
 
D

danr

Member
try unplugging the lamda too, as it will run okay without it. see if fuelling changes.
also maybe clean the maf with contact cleaner, if its been stood still for a while, maybe any contaminants on it have dried hard on sensor..
also ecu temp sender will affect revs, if it thinks engine is cold will overfuel
shit fuel will do the same, i filled up with some recently and it was dropping revs, at one point the rpm jumped up, right down, then back to normal like an arcade machine! was a bit scarey.
does the AEM have a map reload function?
 
Last edited:
G

gtirpower

New Member
danr said:
try unplugging the lamda too, as it will run okay without it. see if fuelling changes.
also maybe clean the maf with contact cleaner, if its been stood still for a while, maybe any contaminants on it have dried hard on sensor..
also ecu temp sender will affect revs, if it thinks engine is cold will overfuel
shit fuel will do the same, i filled up with some recently and it was dropping revs, at one point the rpm jumped up, right down, then back to normal like an arcade machine! was a bit scarey.
does the AEM have a map reload function?
Click to expand...
ok i will try it with the lambda sensor off, it does't have a MAF as AEM run without it, and i always fill up on vpower with an octain booster as it was maped to that.
 
S

skiddusmarkus

Active Member
Is the pipe the MAP sensor connects to back on properly and does it have any cracks in it?

I have a box of millers octane booster for sale if you're interested.I had mine mapped on tescos 99 so don't need it any more.
 
D

danr

Member
skiddusmarkus said:
Is the pipe the MAP sensor connects to back on properly and does it have any cracks in it?

I have a box of millers octane booster for sale if you're interested.I had mine mapped on tescos 99 so don't need it any more.
Click to expand...
whats it like on tesco 99? any mpg improvements, power? i always thought that stuff was full of nasty detergents etc.
 
G

gtirpower

New Member
skiddusmarkus said:
Is the pipe the MAP sensor connects to back on properly and does it have any cracks in it?

I have a box of millers octane booster for sale if you're interested.I had mine mapped on tescos 99 so don't need it any more.
Click to expand...
yes the sensor is on properly and there are no cracks atall, im not interested in the octane boosters just yet mate but i will let you know.
 
S

skiddusmarkus

Active Member
danr said:
whats it like on tesco 99? any mpg improvements, power? i always thought that stuff was full of nasty detergents etc.
Click to expand...


Its fine on it and its local to me so no more 10 mile drives for the shell garages .Mpg went up but that will be due to the remap mostly.
 
PobodY

PobodY

Moderators
Staff member
I wonder who Tesco buy their 99RON fuel from? Around here there's only one place that makes it; Shell Stanlow.
Yes, they'll keep the best fuel and their proprietary blends for themselves, but that doesn't mean the "no name" fuel from them is no good... fuel quality tends to have more to do with the state of the service station and how well maintained their tanks are.
 
red reading

red reading

Active Member
gtirpower said:
basically my R has recently started to this:

when i started the car one morning, it started fine but the revs dropped straight away below 1k rev and puffs of black smoke from the exhaust (car has front exit exhaust) so took the plugs out and checked them and they were black but not burnt so just wiped them down and put them back in and same thing straight away they went black again, have drove the car it still boost well and drives ok but it smokes lightly with black smoke.

there is strong smell of petrol so all i could think was its burning to much fuel.

i have checked for any leaks but everything seems ok, the car was fine just parked it up and started it after about a week and it started doing this.

the car has AEM stand alone ecu with evo injectors fitted and welbro 255 pump.

what could it possibly be??
Click to expand...
What spark plugs has it got in it as iridium plugs have a tendancy to fail if everthing is not perfect and will give the syptoms you discribe.
 
Fusion Ed

Fusion Ed

Active Member
IMO tesco 99 is not that bad. It has pretty good knock resistance, just not quite as much power from memory (been awhile since I did side by side) as Vpower.

I'd be surprised if it was lambda, The map should be pretty close in either respect. Best to get it looked at imo.
 
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