Is This The Afore Mention Rich And Retard?

[lilcrash]

anyway cruising home from work this morning get past the roadworks accelerate from 40 in second a few seconds in and wham feels like i hit a wall a second later it takes off again. its never happened before so kinda random, but yer i just thought i would ask.

[stageaharts]

Have you changed anything recently, boost levels, front mount etc?

Rich and retard feels like a misfire, and typically happens in the mid range (From my experience). It happens due to the ecu reading a large amount of airflow and it subsequently dumps fuel to compensate, thereby protecting the engine from running lean. If you have modified the amount of airflow through your system by increasing boost, adding a larger intercooler etc then you may reach the R & R condition. If you haven't increased airflow, and nothing could have perished/broken to cause this condition then it might be your plugs or coils, it 'feels' essentially the same.

If you have reached R & R because of mods, it's time for, HKS FCD, SAFC/SITC, nistune etc etc so you can either clamp voltage or modify signal inputs (Depending on which fix you choose) to tune it out

Good luck!

[pistol-pete]

yeah a couple weeks after i got my stag i had one of my coils fail. felt as you described. over the next week it happened for longer periods until the coilpack completely died and it would only run on 5 cylinders. felt like crap too

[lilcrash]

my car hasnt had any mods done recently, but current mods are - jjr dump pipe, empty cat case, hks hi power cat back, jjr stealth intercooler, splitfire coilpacks, k&n panel filter, turbosmart type 3 plumb back.

i could describe this feeling like speed cut but at 70km/h like it feelt like for a second the engine turned off

i have been thinking about trying to fix the tune but i cant really decide what to do. im leaning on either a haltech, nistune or mines ecu.

[pipster11]

was it cold?

could be that you were just a tiny % away from hitting r&r but you never did, but now its getting colder over night the air in the morning could be more dense = afm reads as more air flow

go out in the heat of the day and see if it does it

if it still does it then you could be unlucky and have a bad splitfire (uncommon but happens)

[atomaly]

make sure ur tyres are all evenly worn i had a kindof a misfirey / jerky sensation and it turned out to be the ATTESSA system being silly cos of uneven wear! back tyres < front will cause issues, but front < back will not!

i was spitting it cos i hadn't chaged anything and was bewildered as to why it was having issues!

if its not that, the cross it off the list

[iamhe77]

Sounds like fuel cut to me.

Any idea how much boost you were pushing?

I know when I push my car hard, I get fuel cut when the boost hits 1.3bar which can happen around the 70-80kph mark

(surprised the crap outta me the first time, felt like I was going to go through the windscreen)

[lilcrash]

according to the temp sensor behind the intercooler it was 21 degrees. all of my tyres are pretty new, i cant spin the rears without the fronts doing the whole torque steer axle tramp thing so i dont try anymore. the highest my boost ever gets is about a mm or 2 below the top line on the boost guage.

[QWK32]

I'm with iamhe77, how much boost are you running? Or better, did you notice if you had a boost spike as it happened? It sounds just like the neo's boost cut, which as you said feels just like the engine completely cut for a second.

[pixel8r]

I'd say fuel cut as well. R&R will just make the car sluggish for a while (it runs incredibly rich) and usually it doesn't revert to normal until you lift your foot.

My s2 used to hit the fuel cut limit around 10-12psi with a GT30 turbo. It was sudden and pretty sharp, but then power would kick in again a moment later.

As I understand it, R&R is if it detects more airflow than it thinks it can handle, and the fuel cut is when it detects an extreme case of increased airflow. I think its kind of like the ecu panicking. I'm not sure if the fuel cut is boost-level related as well.

Some form of tuning should help eliminate it, otherwise just turn the boost down a bit.

Edited March 12, 2010 by pixel8r

[**RB2530**]

Listen carefully because I am going to say this only once...(have said it many times before though..)

1. R&R is the ECU richening AFRs and retarding timing.

What triggers this?? Excessive knock picked up by the knock sensors...Once triggered the ECU creeps back to normal maps gradually over time...

The intent of R&R is to protect engine from damage (due to pinging) if car is filled with bad or low octane fuel...

2. Airflow cut is triggered when AFM voltage exceeds a mapped threshold (has nothing to do with R&R). Threshold voltage increases with engine rpm. When triggered ECU instantly drops fuel and spark. As soon as AFM voltage drops, fuel and spark get reinstated. Thats why if you dont back off throttle car will behave as if it is missing very badly..There is no adjustment to maps.

What triggers this?? Anything modifcation thats will results in significantly increased airflow into the engine as measured by the afm..ie Less restrictive intake, Less restrictive exhaust, higher boost, bigger turbocharger..

The intent of airflow cut is to protect engine from overly lean AFRs and/or damaged to turbocharger due to excessive spooling should there be a problem with boost control..ie split WG actuator hose or WG jammed actuator...

Contrary to common belief, these features were not placed in the ECU by the CIA, NSW highway patrol, RTA, FBI, nor are they some unexplainable scientific phenomona etc etc. They were simply put there by Nissan engineers to help get their turbocharged cars through a warranty period...

Hope this makes sense...

[QWK32]

Good explanation Paul, but to add to what you said, the NEO RB25 in the R34's and S2 Stagea's also has an additional overboost protection, "boost cut", detected by a MAP sensor that the NEO has. Usually hit around the 13-14psi mark, but I have heard of people hitting it earlier.

[lachlanw]

mine did that . it only did it at about 6 grand in 3rd . standard boost controll with exhaust upgrade and front mount . ebc fixed it . it also only ran 5 psi after it did it untill i turned car off

[mad082]

my 33 used to do this on cold mornings when i was running 13psi, and only at 100% throttle. once the car had a bit more warmth in it (like had come up to full temp and then driven a bit harder) it would stop. if the car had only just come up to temp and you gave it the beans it would do it, but then a few mins later it wouldn't. i just put it down to having the boost set at the limit of what the ecu liked. for me it would happen at about 3000rpm and it felt like someone had just turned the key off and then back on. had it happen in second once and when it kicked back in it started to light up the rear tyres.