driftin8ez

that why i said it shouldn't be a problem. Not it isn't a problem. Do you guys have this strange kind of missfireing at idle. Like a subtle pop every once and a while? This could be the key to fixing our problem. It did the "popping" at idle with my na and now my 13bt that i just swapped in. So i dont really think it could be "engine" related. The only things that are the same between engines are basically the alternator and the coils. so basically it must be something electrical which is why i figured i would throw in an ignition box to amplify the spark.

Chief_MC

I had pops when idle and idle was pretty unstable but that's actually other signs of running rich and barely a problem alone... at least in my case, 'cause i've tuned things i could tune, like TPS, ignition etc...

MattB

i have a lot of the same symptoms...im kinda wondering though...could it be that i didnt replace my fuel door gasket...when i did the fuel pump...or, could it be that my TPS is just broken...and i removed my emissions so i know there arent any vac leaks (new gaskets from block up)

Chief_MC

I have a smell of gas from exhaust and not really under the hood, but a pulsation damper would leak that much to 'cause a big drop in mileage i'm sure it would 'cause a one big fireplace from your car a long time ago... so that's barely an explanation...

RX-7Havik

I am running way rich as well, but I get close to 295 mi to a tank. I also have some popping @ idle. I am actually taking her to a shop that specializes with FC's and have them check out my running rich problem. Let you know what they find out.

fast86rx-7

i also have these problems but my popping is almost rythmic like almost once a second but i also get alittle hesitation at high rpm under part throtle and even less under wot

RX-7Havik

Our common popping issue could be related to the ole anti-afterburn thinga-ma-jig.
least of our problems I would think.

driftin8ez

I'm pretty sure that only kicks in on decel. or when you let off the gas. Not at idle. Something else is a foot. not sure what.

GloryDays

uhh i dont know but i'll post anyway... make sure youre wired correctly, despite how dumb it may sound, i found out that my spark plug wires were crossed, i switched em back and now theres no popping.

RETed

Since my name was mentioned...

This is an NA, right?

The gas mileage isn't low, but it isn't uncommon.

What are your driving habits?
If you're doing all stop-n-go driving (i.e. city driving), then the mileage is okay.

Are you still using the stock oil injection?
If so, then the carbon layer is from the oil.
That is normal.
Or are you premixing?
If so, what type of premix and how much?



-Ted

Alex6969

the popping is from you engine being cold and the ecu going into fuel dump mode, a fairly common problem

nvdrx

^^^^^^ this is true, you guys should notice it wont pop once its warm? my s5 pops in the morniing onstart up, once warm, beautifull

Chief_MC

Yes it is a 88 GTU, the mileage i mentioned (13 MPG) is a city only driving with heavy traffic (ie freq stop-go), but what confueses me is that if i drive it heavily or like a grandma the mileage is still the same...

I have stock oil injection, but the carbon layer is too thick for it, 'cause i have another 13b disassembled and it has many times (!) thinner carbon layer, + gas smell from the exhaust all of it makes me think that i'm running way too rich all the time...

Chief_MC

Mine's popping even after it's at normal opearational temp.

RETed

That is correct.
The only way the mileage goes up is when you go for non-stop freeway trips.
My '87 Turbo II gets consistent 13.0 to 13.7 mpg, and the car sees mostly city driving, but very little stop-n-go.
Even when I baby the car, I don't get that better gas mileage.
When I do a highway sprint, then the mileage starts to come up significantly.


It might be due to the type of oil you're using?

Are you really from Russia???



-Ted

Chief_MC

You might be right...

I'm using Castrol 15w40 Protection 3+... i think it is a good oil...

I'm not from Russia, i'm from Ukraine, although it is an ex-USSR territory as well...

driftin8ez

+1 on that. i still dont think its normal.

Chief_MC

It's absolutely unnormal... And the fact that a lot of FCs do have that doesn't making it normal...

MattB

mine still pops as well.


my car:

87 S4 TII with S4 J-spec
emissions removed
Rtek 1.7 ECU
720cc secondaries
ported WG
10 PSI
full 3" exhaust
3" TID
K&N filter

all new gaskets and vac hoses from block up

few things i need to check:

fuel pump gasket (didnt replace when i did my pump)
vac leaks ( i reused my injector grommets on my primaries cause i couldnt find new ones)
(i have the home depot BOV so...who knows about that one...)
i reused some of the emissions stuff as a temp fix till i get block off plates...(so they are on there...just capped off.

thats all i can think of that could be a big problem.

i adjust my TPS just the other day to 1k at idle, and it was at 4.77 at WOT so thats fine.

the idle mixture adjust POT is very hard to get perfect since my car wont idle at a low enough RPM...cause my BAC is as low as it goes...(the plug on my TPS isnt plugged in, but the bottom line that goes to the intake isnt blocked...it is still there.)

driftin8ez

Well here is my set-up for some comparison:
S5 13bt Jspec
all emmisions removed and blacked off with the correct block off plates and RTV ultra black
3" TID with cone filter
3" RB downpipe w/ 3" - 2.5" dual catless downpipeback
semi ported wastegate. I need to get back in there becouse it still creeps a little.
TII fuel pump with new filter (I'm an N/A convert.. Full S5 drivetrain swap as well)
new fuel filter
Just set my tps with multimeter to 1k idle and 5k wot
I have a vw 1.8t diverter valve
set mt timing using the timing marks and restabbing the cas.
still usinf the stock omp set-up
Things i need to check:
I have ultra black rtv sealant for a UIM to lim gasket. Just ordered the right gasket from mazdatrix.
I also didn't replace the orings and gromets on all my injectors. (ordered those from mazdatrix aswell)

seems we both need gromets for our injectors. Maybe that is the key. Funny thing was when i first started the jspec it didn't pop at all and now it seems like it is doing it more and more. I did have brand new plugs when i started it. They are now covered in carbon:-(

Chief_MC

Guys, that could be the key! Injector o-rings and gromments, 'cause that ones from a few things left to change for me to be sure i've done everything... Should try that...

MattB

im gonna go pick up some 10mm ID hose...according to FC3SPRO that works just fine...and it lasts longer cause its better material...

and o-rings dont cause VAC leaks...they cause GAS leaks...so just replace the grommets if already replaced the O-rings...like me...cause autozone cant find the grommets for me

MattB

a vac leak would cause too much oxygen to get into the system...right?


so therefore there would be not enough gas...and we would run lean...not rich...so that doesnt really make sense...


worth a shot but i kinda doubt it

Chief_MC

running lean is almost as bad as running rich... you will have a bad mileage and low power...

driftin8ez

well i got my tracking number from mazdatrix but i didnt track when its coming. im getting all new manifold gaskets and new gromets and orings. Ill let you know whats up. On a side note i did a water treatedment today on my car and it seems to be idling a little better and "pops" alot less now....