SOHC_MShue

Well it all started last summer when i first threw my turbo setup on. My fuel setup was dsm 450's and uberdata. My car would slightly ping at wot in 3rd and 4th gears...it wasn't very noticable, but it was there. I tried everything to fix it including running my car pig rich and backing down an assload of timing. Nothing really seemed to work. Eventually i ordered a new walbro 255lph fuel pump. After installing that the problem went away. I could no longer hear the problem.

Fast forward to this winter..once it started getting cooler outside the pinging came back. I could get it to go away, but i would have to again dump in tons of fuel or back the timing down to unreasonable amounts...like 10* total timing@10psi. Whats weird is that I finally got a wideband to check my afr's and on the normal maps i had been running i was running very rich! My afr was dipping into the 10's at wot. Eventually I got an external wastegate and now I can't hear ****. I don't even know if the sound is there anymore or not.

Also I have checked my plugs(never any signs of detonation..always light brown even after a wot pull and immedietaly shutting down the motor). I even swapped my injectors out for a friend's 450's and still heard the sound. Now I have leaned out my mixture to be running around 11.5-12:1 and my car has never ran better. Although I suspect that my motor is still pinging(i think its such a small amount that for some reason it hasn't done any real damage to my motor even though I beat on it all the time).

Now the question is...could my fuel pump be going bad and I am still able to get the correct 11.5-12:1 afr's. The only reason I suspect the fuel pump is because replacing my old stock one had fixed the problem in the first place, but then the problem came back.

SOHC_MShue

also if it matters my fuel pressure at idle reads around 46psi.

SOHC_MShue

bump

SOHC_MShue

anyone have info on this??

PM-Performance

i could see the fuel pump going bad and maybe having an on and off problem.
A New Walbro shouldnt be doing that though.

Are you sure its ping and not just something rattling around under the car?

Too little timing can cause ping form what I have heard too.
Bad Gas maybe? Or has this been thru multiple refills?
Injectors maybe missfiring at times? But I guess you would get a code for that.

Some things to think about though

SOHC_MShue

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by itr206 &raquo;</TD></TR><TR><TD CLASS="quote">i could see the fuel pump going bad and maybe having an on and off problem.
A New Walbro shouldnt be doing that though.

Are you sure its ping and not just something rattling around under the car?

Too little timing can cause ping form what I have heard too.
Bad Gas maybe? Or has this been thru multiple refills?
Injectors maybe missfiring at times? But I guess you would get a code for that.

Some things to think about though</TD></TR></TABLE>
i am sure its pinging because i was able to make the sound quiter or get it to go away by removing a butt load of timing or running my afr's like in the low 10's. Its not bad gas because its been over multiple refills. Also i've tried a whole other set of injectors with the same results so i have kind of ruled them out for now.

PM-Performance

what compression and fuel ?
10degrees @10psi seems a bit low.
What timing were you running before that?
Does it ping thru the whole RPM range? Certain spot?
Maybe there is a fueling/timing problem at a small spot on the maps?

Cold weather will do fun things like this also.

SOHC_MShue

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by itr206 &raquo;</TD></TR><TR><TD CLASS="quote">what compression and fuel ?
10degrees @10psi seems a bit low.
What timing were you running before that?
Does it ping thru the whole RPM range? Certain spot?
Maybe there is a fueling/timing problem at a small spot on the maps?

Cold weather will do fun things like this also. </TD></TR></TABLE>
9.6:1 compression. 93 octane fuel. I don't always run 10 degrees...thats just when i was retarding to make the sound go away. Right now i am running around 16 degrees at 10psi...which is still low, but i have a y8 which has a base timing of 12* and not 16* like the z6.

It used to ping right at vtec crossover...which was also where my boost would shoot from 5psi to 10psi. I've since gotten an external wastegate that fixed this problem so now I hit 10psi by like 3k rpms. Except now i can't hear **** over the wastegate . The inboost timing maps I am running right now are a p28 with a very conservative step retard..minus 4* across the entire map because I have a y8 instead of a z6. Y8's have a base timin of 12 and z6's have a base of 16 so thats why i subtracted.

PM-Performance

what do the maps look like right at vtec crossover then?
or in the low boost maps?

SOHC_MShue

this is what my timing maps were looking like the last time i heard the sound when i had my stock wastegate..they aren't too much diffent now. Probably not as steep of a drop in timing though from 0psi to 11psi. Now it just starts out at lower timing at 0psi.

SOHC_MShue

up . I need some expert advice guys.

093turbo16

iTrader: (2)

how about the re-checking your timing on your motor.

SOHC_MShue

i have checked it a million times. Its actually around 11* base timing..not even all the way to 12.

SOHC_MShue

up

hybridsol

Questions:

Have you replaced fuel filter?

Have you looked for fuel leaks?

Do you have a fuel press gauge in the car? If not, have you tried another FPR?

Assuming you're running a stock fuel rail... is the Y8 lage enough diameter to support 450's?

I really don't think these are your problem, just questions... I think originally you had an issue with the stock pump not delivering enough fuel... mabey running rich all that time after the pump swap gave you some carbon build up which surfaced with colder temps??

Just my $0.02...

SOHC_MShue

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybridsol &raquo;</TD></TR><TR><TD CLASS="quote">Questions:

Have you replaced fuel filter?

Have you looked for fuel leaks?

Do you have a fuel press gauge in the car? If not, have you tried another FPR?

Assuming you're running a stock fuel rail... is the Y8 lage enough diameter to support 450's?

I really don't think these are your problem, just questions... I think originally you had an issue with the stock pump not delivering enough fuel... mabey running rich all that time after the pump swap gave you some carbon build up which surfaced with colder temps??

Just my $0.02...</TD></TR></TABLE>
the fuel filter was replaced about a year ago so that should be straight.

no fuel leaks

only fuel pressure gauge is on top of the fuel filter. I haven't tried another fpr.

stock y8 should be plenty for 450's.

where do you think the carbon could be building up on? It is weird that it just came about once the temps got cold. I know that the cold should cause me to run leaner, but i have tuned my car in the cold weather and my afr's are dead on where they should be. Whats scares me now though is that i can't hear the sound ever since i got my new wastegate and i can't really diagnose it because of that.

SOHC_MShue

SOHC_MShue

dennis

Are you POSITIVE about your c/r? Mine turned out to be a little higher than I thought. Are you running colder plugs?

SOHC_MShue

well there is no way it could be higher than 9.6:1. Its a stock motor. If anything it would be .1 higher because the head has been resurfaced once, but they said they barely took anything off. I'm sure i wouldn't have a problem with 9.7:1 anyways.

dennis

Yeah, you should be fine then in that dept then. Maybe try colder plugs? What are you running now?

SOHC_MShue

since hearing the pinging i have switched over from 6 to 7 series plugs. So that should be plenty enough.