Car Starts Popping When It Comes On Boost

[joshw33]

iv got a 33 s2 i just but on full exhust intercooler and boost controller i took it for a drive and it was alright on 5 psi and i turned it up alittle bit about 7 psi and still alright i turned it up a little bit more and

soon as it hits boost it starts popping so i but back down 5 psi and it still doing it

[spranga]

Intercooler hose loose?

[joshw33]

i checked that and still the same

[SargeRX8]

Its misfiring. The spark isn't hitting the spark plug. Put some tape around your coil packs. There is a guide about it here. How old is the car(KM wise) if you know its legit? High K"ms they could have cracked from the heat and now they are on their last legs.

[DVS JEZ]

get some new spark plugs BKR6ES, NGK-R try and get the .8mm plug gap(part as i quoted BKR6ES), supercheap normally stock these , if that doesnt fix it basically u need new coilpacks

[Nissan Nutter]

Had the same issue with my car on it's last tune dvs32r is on the money, i ended up having to re-gap the sparkplugs and put some new coil packs in. The problem hasn't come back since.

[Luke_GTS-T]

please use the search function... this has been covered 10000000000 times

[joshw33]

i put new spark plugs BPCR6E and its a little bit better on low boost 5 psi its ok but as soon as you put a bit

of boost it starts popping about 4500 to 5000 rpm and then clears up a bit so im going to try sealing the

coils

[DVS JEZ]

did you get the .8mm gap?

if you have then you need new coil packs. try yellow jacket, cheapish $400 and are supposed to be really good

[joshw33]

i put new plugs in it [bPCR6E 0.8mm] ran ok on low boost but as soon as you put boost in to it it runs like shit

so i tried to silicon the coil pack still no good then i went and bought new coil packs splitfires runs heaps better

no missfire as soon as it comes on boost it starts pulling and then about 4000-5000 rpm it doesn't seems to pull as hard

and then it starts pulling again so im thinking i might need to try a colder plug or smaller gap

any suggestions would be appreciated thanks

[89CAL]

Stock ecu and extra boost do not mix. How much boost?

Usually anything over 8psi in a 33 will cause issues

[joshw33]

running 12 psi spikes to about 15 psi

[Galois]

Those spikes may make the stock ecu crap itself, maybe lower boost or go aftermarket ecu?

[89CAL]

15psi is to much for a stock turbo for a start.....

[benro2]

running 12 psi spikes to about 15 psi

You are definitely hitting "R&R" (richen and retard). This is where the ECU is trying to protect itself by richening the mixture and retarding the ignition. It's because it's seeing too much airflow for what it thinks is safe for the car.

As others have said, anything over about 8 psi will cause this. I have seen it happen on my own car (dead stock except for manual boost controller) and in the cold weather I run a bit over 7.5 psi and get the exact same issue. Same rpm range - I think because this must be the greatest volumetric efficiency of the engine (ie: it's flowing too much air more easily than at other rpm).

The only ways to fix this are to either:

1. Restrict boost to < 7.5 psi, or

2. Run whatever boost you want (around 10 psi max on stock turbo or you will stuff it pretty quickly) and run a fuel adjuster. You can do this on-the-cheap with a Jaycar Digital Fuel Adjuster kit, but beware, unless you can either build it yourself with some level of confidence (ie: you've built a few kits before), or you can find a pre-built one, I'd steer clear of this option. I attempted this myself and never got it to work properly - and a lot of others on these forums have had bad luck with it too. If you can, budget say $500 for a brand-name fuel adjuster, like this Blitz "R-FIT" (Fuel Intensity Tracer).

While I was at a performance workshop the other day, the tuner there told me about the Haltech Platinum Interceptor which is a piggyback ECU that can do both electronic boost control and fuel adjustment, amongst other things. He said they'd do it for about $700, and it's marked on Haltech's website for $799. This is actually a pretty good price considering what it does and that you'd be paying say $350-500 for an EBC and another $450-500 for a fuel adjuster.

Food for thought!

Edited April 6, 2011 by benro2

[89CAL]

If you want to do it cheap:

Nistune

Turbotech boost tee

12psi

Tune

Should run alright then

[benro2]

If you want to do it cheap:

Nistune

Turbotech boost tee

12psi

Tune

Should run alright then

The only thing is, with those manual boost controllers, they vary a LOT with the weather. I think I've got the Turbotech on mine now (is it the blue one with the little ball + spring in it?) and it varies by about 3 psi from hottest to coldest weather.

Whereas, if you run an EBC you can have it rock solid on your target boost no matter what the weather.

I used to run the Jaycar EBC (never worked properly though, kept burning out a resistor, just like the DFA) and that used to hold 10 psi dead on in any weather. It's because it's linked to the injector duty cycle. That particular EBC also allows for a boost "curve" to be programed in, something that's not that common in many brand name EBC's. I don't mean just the ramp rate, I mean where you could conceivably run 10 psi from say 2-4k rpm, then 12 psi from 4-6k, then taper back down to 8 psi by 7k if you wanted. The only downside to the Jaycar EBC is that it's a bit hard to tune, in that you can't just say "run 10 psi max" and it'll do it - you have to program in a boost "map" - basically values that map to each injector duty cycle, but Sydneykid provided me with a base map that worked very well for 10 psi. The Hand Controller kit (lol, the only one of my kits that actually WORKS!) can be used to tune the EBC "live" so you can do some road tuning.

[89CAL]

I thought the turbotech's were one of the better and cheaper manual boost controllers. I used to run a turbosmart dual stage which everyone says is useless but it did the job fine, not as well as my PFC boost control kit but good enough for a manual controller. If he's doing it on a budget just saying it's the cheapest boost controller that performs

[benro2]

I thought the turbotech's were one of the better and cheaper manual boost controllers. I used to run a turbosmart dual stage which everyone says is useless but it did the job fine, not as well as my PFC boost control kit but good enough for a manual controller. If he's doing it on a budget just saying it's the cheapest boost controller that performs

Yep, I have heard that they're supposed to be one of the better/cheaper ones too, however MBC's are nowhere near as good as EBC's Yep, if you're on a very tight budget you can use them, but all you can really do with a stock computer is *maybe* run another 1 psi boost before you start getting R&R... and if you do hit R&R (easy in cold weather with an MBC) then you're going slower than before anyway!

However, there is a way to reroute the pipes to bypass the stock solenoid so you're running ~10 psi - it's in a thread somewhere on these forums, Sydneykid details how to do it. This is the cheapest and most reliable way to do it - no boost controller required at all!

The tuner I spoke to recently also said that the little ball in that Turbotech can get dirty pretty easily and when that happens it doesn't control boost properly anyway.

So basically, if you're gonna push past 7.5 - 8 psi, budget about $700-800 (non-installed) for a decent EBC and FCD - or use a combined one like the Haltech Interceptor I mentioned, or something similar - and you can fine tune even more.

Edited April 8, 2011 by benro2