Rally car running stupid rich..............help

J

Jon Olds

Well-Known Member
Had to pull out of a rally yesterday because of a stupid rich running condition that developed mid way thro a stage.

No fault codes. ie 5 long, 5 short pulses on ECI light.

Connected my Nissan consult laptop on, after a new set of plug it started, but it was still as lumpy as anything.

Could you guys please have a look at the live values I got at tickover, and help me out please;

RPM : 1000 (lumpy, held with a constant small throttle)
Airflow : 2.27 (dashboard display meter reads zero to 6.0)
Inj duty cycle : 8% (range 0 to 110%)

(I'm sure it normally ticks over with 2% inj pulse length : dash display apex multichecker now aligns with computer and shows 8%, but I have fitted my spare AFM. Are they both F'ed? )

Water : started 10C and started increasing : looks ok.
O2 Sensor : 0% (range 0-100% does this mean its giving zero output? should it sit at 50%?)
AAC : 73% (range 0-100, dont know what this is)

Help appreciated, would a knacked O2 sensor do this? or is the second AFM I tried also giving too much signal (ps It has an apexi SAFC2 in series with the signal)

Regards
Jon
 
J

Jon Olds

Well-Known Member
Knew I had missed something: in a hurry.
Throt pot : 0.62 (range 0 to 6, think it reads about 0.44 when the throttle is shut: I have screwed the mech stop up, as I removed the idle valve and all the gubbins)
The ignition timing was 20 degrees before.

Also tried winding the SAFC fuelling hard negative around 1000rpm, and it didnt make any difference, to anything. Took it from 0 to -30%. The SAFC speed signal is working ok
 
I

iomegalinux

New Member
2.27v at idle is way too much. maybe clean the maf wire. did you change something ? like the lenght between turbo or maf ?
 
J

Jon Olds

Well-Known Member
this looks wrong to me too. but i did fit my spare afm on the day. no change. i didnt have the laptop with me. the other thing is the lambda probe. where should that reading sit? if the lambda fails, does that massively change the mixture? no changes made to the installation as it was running well on stages 1-4
 
J

Jon Olds

Well-Known Member
Will do. If there is a blockage, would the fuel pressure reg be able to do its job properly?. My tapping for the fuel pressure measurement is on the fuel rail, and looks ok.
Still confused. Just tried a third AFM on and it still reads around 2.5 at 1000rpm. Still seems high. All other readings are as stated above.
Wiring problem?
BOV is not stuck open. Need to take the bumper off, examine the boost pipework in case there is a split or something I cannot see.
Think the Lambda reading is so rich that its off scale, hence the reading of zero.
 
D

danr

Member
think the standard ecu uses a default af value if it sees its dead.
try disconnecting it and see if anything changes .
 
M

MarkTurbo

Well-Known Member
Just a thought but the safc hasn't done anything stupid like changed maf type or voltage settings has it?
 
J

Jon Olds

Well-Known Member
Found it, thanks guys. As dencon says, when I had a 'rub' at one of the chicanes its pushed the intercooler flexi off, behind the (twisted) bumper.
Obvious now. Lesson learnt
 
J

Jon Olds

Well-Known Member
yes, I know. what threw me was the dashboard lambda not showing what I was expecting, also the boost controller managing to achieve 1.2 bar, in spite of the leakage. compressor must be able to deliver far more air than the engine can swallow. also, I was relying on my co driver to monitor key engine parameters, and it was expecting a lot, since it was his first ever event.
 
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