Rich & Retard High In The Rev Range

[Birds]

R33 GTS-T

Note: Both sparkplugs and coilpacks were replaced about 2000km ago and the car was running without fault before I started playing with the exhaust.

Been doing a bit of turbo-back exhaust modification lately, and after cracking the shits / returning to my original dump/front pipe, I'm now left with something of a rich and retard problem. It only happens high up in the rev range and only when giving it full throttle. Because of the wide open throttle thing, I suspect it's actuator or vacuum leak related. I haven't touched the vacuum hoses though. My wastegate flap was getting jammed by the aftermarket dump pipe after I installed it, could this have damaged the actuator diaphragm?

Another possibility I'd like to put forth: because the jammed wastegate flap caused my turbo to boost almost infinitely until boost cut when I had the aftermarket system on...I'm thinking the ECU has logged a fault code or something and because I haven't reset it (the thought to do so has only just occurred to me), so perhaps an ECU reset will fix this? Will try this tomorrow...

Interesting to note is that my engine under some conditions is still boosting past the normal .5 bar up to about .6 and sometimes .7 - this is where I notice most R&R occurring. Doesn't seem to be any R&R occurring at or below .5 bar.

Suggestions? I'm seriously regretting ever touching my exhaust system

[NickR33]

Its just the ecu's way of protecting the engine... when it sees too much airflow through the afm it will start to retard the timing and richen the mixture... you might have damaged the actuator making it open later which is causing it to R&R... even still just having an aftermarket exhaust on there can sometimes trigger R&R in the right conditions... it increases airflow through the whole system but you won't see it in a boost increase, the afm however does see the extra airflow...

when I first boosted my old car I used to get it a lot so I used a SAFC to trick the afm... even still on cold nights it would sometimes happen... best mod for them is a Power FC and good tune

also dump pipes don't make a huge difference... the exhaust housing on the stock turbo is where the restriction is, not much gain fitting a dump pipe (although people will tell you otherwise)

[Birds]

Yes a Power FC was my immediate thought for a solution lol. I will be heading down that track...but thought I'd try and diagnose the problem before this because it might not be directly ECU related and that will just make things hard for a tune.

I think I'll try fitting another actuator to it. What bugs me is I now have my original exhaust back on and it's still doing this shit, when it wasn't before with the original exhaust.

Cheers.

[NickR33]

yeah that points to something being damaged... or something not being reinstalled correctly...

you could have also stumbled on a bad batch of fuel and the ecu is retarding the timing to protect the motor but that's a long shot

I don't like people saying to throw more mods at a problem but in the case of 33GTSt's they do really well with some a/m management and good tune... I mucked around with an SAFC for ages but should have just done it properly in the first place... they drive really nice with just a full exhaust and good tune... mid range picks up massively with a few more psi and a better cooler too

[mad082]

what are you actually feeling? is it missfiring or just getting sluggish? when i was hitting rich and retard in my 33 it wouldn't missfire or anything like that, it just killed the power for half a second then kicked back in.

if it is a missfire:

what series motor do you have? if it is a series 1 with the ignitor pack then that could be the issue since you have replaced coils and plugs.

[Birds]

No misfire as far as I know, it's a complete dead spot in the rev range. I say this because I can take the RPM all the way to 7000 without a problem, as long as I don't do it with full throttle.

It drives fine with 3/4 throttle applied (which incidentally keeps the boost just under .5 bar too). But if I go wide open throttle, at .5/.6/.7 bar the revs climb sort of jerky and power comes on and off, almost as if it's switching between on boost and off boost.

Farkin pain in the ass. I reset the ECU and I thought this fixed the problem but it appears to still be there. Gonna replace actuator (anyone got a spare?) and maybe dump pipe gasket...these are the only physical things I touched when playing with the exhaust, so unless it's one big coincidence, I don't see what else could be doing this.

[mad082]

0.7bar is only around 10psi so i wouldn't normally think that it would be hitting paris hilton (rich and retarded, LOL) at that boost level, but every car is different. i would look at getting it put on a dyno just to see what the AFRs are doing. if they aren't fluctuating in the dead spots then it will be an ignition/electrical issue.

[jutstar]

I was having the same issue it seems everyone with the standard ECU and modded R33 GTS-T on here has had.

Get a re-mapped ECU , SAFC or new standalone ECU or change your mods back to stock.

I got a toshi re-mapped ECU and now my engine isn't doing a Paris Hilton anymore.

[Birds]

Hahaha Paris Hilton, that's gold. Sounds like the go...I'll stick her on a dyno and check out the AF ratio. Probably replace the actuator and dump pipe gasket too. And get a Power FC, which I was going to do anyway when my car didn't have issues.

Gotta love cars.