AFR at wot and cruise....NOW FIXED THANKS TO MEMBER INPUT

[mbarryracing]

Barry, bummer. Evidently you have a shop gremlin that is related to the one I had messing with my sled...
Keep this in mind, a misfire in the cylinders will also show a lean reading on the AFR because the unburnt oxygen in the charge is blowing right thru and out the exhaust, getting picked up by the sensor. So the AFR going lean while it's sputtering and dying doesn't always mean it's really lean.
Man, you can't rule anything out. It could be electrical or a fuel problem. Yeah, could be a regulator?

 

[ghost rider]

Thanks Mauri,
i certainly do have a gremlin…..funny thing is when it's on it rips.
I'll replace the regulator with a borrowed one and see what happens……

It seems to be pig rich to me because when it dies and re-starts it has to "clear" it throat so to speak.
but to just pig out during cruise for no apparent reason is very strange.

Maybe my ex wife keeps sneaking into my garage at night to screw around with the sled.

going to try a softer spring on the BOV and test today…..It's -17 in my garage so I'm not tearing the carbs
apart in that cold…..

Barry

 

[mbarryracing]

Barry,
Can you get a fuel pressure gage mounted where you can monitor it while riding? See if it is fluctuating or doesn't repeat at idle after being on boost?

 

[rxrider]

The on and off thing makes me agree With mbarryracing on the possibility of an electrical issue.

Another thought.... stuck float needle that comes and goes, flooding one cylider every now and then???? it's possible.

 

[ghost rider]

See below...

 

[ghost rider]

Ok as of today I put in a softer BOV spring and it helped a lot... No more stalling or random
Flooding... Coincidence?
It still sputtered and popped at wot because it was at 10.0 AFR ....
I still need to put in the 127.5 jets.
Should I changed out the neddle valves while I have the carbs off - just to be sure?
I will also try another regulator just to be sure.... Although I will try one thing at
A time so I can find out what the gremlin is that's killing me slowly..........
Also a good idea to monitor fuel preasure durring boost and after boost.... I can rig
Something up to try that.
Going to be -3 most of the week so I can work in the garage without freezing
My a@$ off

Thanks for your help guys !!!!!!!
I will hopefully post my success report....


Barry

 

[Riceburner]

IMHO. Do not change the needles. Been there done that. Back to stock.

What soft BOV spring did you put in? PSI ? Which BOV / type of BOV do you have?

 

[ghost rider]

IMHO. Do not change the needles. Been there done that. Back to stock.

What soft BOV spring did you put in? PSI ? Which BOV / type of BOV do you have?

I have a turbo Xs made for 1 litre engines ... Stock spring was crazy stiff because it was
Made for a car with lots of vacuum so I had to source out springs with the same length as stock but with softer coils... I tried 6 different ones before the final one as listed above.
It is all trial and error as no other spring is offered with this BOV - FYI it's not Chinese made
(Shoot me if I ever get that cheap)
Really I should have bought a better BOV but I was being cheap paying only 175.00 for the turbo Xs when a tial was my preference, I have two tials on my car and they are fantastic
But at 300.00 each - not cheap. Having spent. Almost 3 grand on my skid this year I kind of blew the bank, so any other expense had to be receded.
Good news is it (BOV) works great now and is dumping boost every time I shut the throttle
Thus stopping the flooding from excess boost to carb bowls to cylinders.....
Installing the 127.5 mains today as you and Jan suggested ... The 130's are still too rich
Idle is great cruise is now great... Wot improved -as in sputters but now it doesn't stall
still pig rich at 10.2 looking for 10.8 -11.6 for now.
I have a radar run this weekend and would like to make a decent showing.... Suspension is good to go this time out. Just need this last bit of sputter to leave me thr f@&k alone
So to speak.
Ps) changed all coils ...they were older than me I think.
Will put in new plugs (again).......Old ones look pretty black.

After that I will be thinking about golf season......my wife doesn't want me to ride the pavement... Dam, she's my third and by far the best so I tend to pay attention to her.
Below is a video link ... Sputters at the end of the run( out of sound range) ... But the 660 time is great as it pulls hard from the start.

http://youtu.be/tFZcjFwzBhQ


Barry

 

[srxguy]

stator? just thinking out loud

 

[rxrider]

Is this With the 127.5 mains?

Have you done a carb sync lately?

 

[ghost rider]

Is this With the 127.5 mains?

Have you done a carb sync lately?

No Jan doing the 127.5 right now... Will sync after....
I haven't done a syncing for a while.... I'm due.

 

[ghost rider]

stator? just thinking out loud

I wondered that myself ... But would it not then drain the battery?

 

[ghost rider]

Finally ...... WOT 11.4 AFR no studders no burps.( leaving a little on the table)
Four main factors, one; 127.5 jets and a serious carb clean.
Two ; one of the carb boots had a leak (read tear)
Three ; one of the coils was arching so I replaced all 4
Four; BOV install, plus finding the perfect compression spring
The problem(s) took 2 months to sleuth.... But I had lots of help.

I know if I had fuel injection and a newer sled, I would eliminate a lot of the potential
For problems ... But I have that in my car and it's just not my thing to
let the computer do all the work of keeping the perfect AFR during boost,
Sift gears in milliseconds with a flip of a paddle... Hell, it even controls my exhaust volume.
Although fun and excilerating it removes the connection to the machine for me....
It's just too easy.
I want to wrench something old school with enough HP to make me grin.
And keep the costs down......and yes; have some problems to deal with
and sort out- it keeps my aging brain active.

BIG Thanks to everyone who helped me out on Ty; your knowledge
Is immeasurable and without it I would have drove the sled
off a cliff -it was that frustrating. -no not really, I just like to feel the rush of the turbo
and when it's not there I will spend my nights out in the cold unheated
garage, tools in hand, trying to get that boost back to spec, before the weekend ride.

Today is a good day.

Best,
Barry

 

[rxrider]

Great News Barry
Good thing With the AFR's ....
You have a little fuel left if you decide to up the boost a little. The higher the boost the leaner the charge. Perfect AFRs at WOT are 11.8-12.0.

 

[ghost rider]

Great News Barry
Good thing With the AFR's ....
You have a little fuel left if you decide to up the boost a little. The higher the boost the leaner the charge. Perfect AFRs at WOT are 11.8-12.0.

Thanks Jan, you have been a great help to me.
I'm thinking about running 12lbs this weekend for a race.
I have no head shim(yet) but I have 110 octane.

Barry