Lean Spot At ~2400 RPM...What the?
08-11-2011, 05:10 AM
#362
Charles, I'm ready to give this a try when you're ready for orders! 
Thanks for the feedback str8dum1. Sorry to hear about your turbo - you overoiling it? Can you over-oil a journal bearing? Maybe get that forced performance filter on there and a pressure gauge so you can monitor it.
You could just use this:
Thanks for the feedback str8dum1. Sorry to hear about your turbo - you overoiling it? Can you over-oil a journal bearing? Maybe get that forced performance filter on there and a pressure gauge so you can monitor it.
Last edited by rcdash; 08-11-2011 at 05:30 AM.
08-11-2011, 07:25 AM
#365
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that's very odd on precision since they have oil rings instead of seals. When i called precision they told me it's like a piston ring in the respect that the more pressure against it the tighter the ring presses into the journal to seal.
They told me that usually and residual oil left in the turbo after shutdown will seep past the rings since there is no pressure holding a tight seal the smoke is from the oil that has leaked with the car is out of boost or sitting turned off.
After fogging my neighborhood many times then re-routing my drain lines and cleaning the turbo my issue went away.
Now, i'm not turbo engineer, i'm only repeating what precision told me when i called them. They said the only times they see failure with the sealing and oil leaking during boost is a broken or defective sealing ring. They said normally the sealing rings will outlast standard oil seals on other turbos by many times.
and yes, i want rails now so i can cruise in my car without it bucking like i'm 16 year old just learning to drive a clutch.
They told me that usually and residual oil left in the turbo after shutdown will seep past the rings since there is no pressure holding a tight seal the smoke is from the oil that has leaked with the car is out of boost or sitting turned off.
After fogging my neighborhood many times then re-routing my drain lines and cleaning the turbo my issue went away.
Now, i'm not turbo engineer, i'm only repeating what precision told me when i called them. They said the only times they see failure with the sealing and oil leaking during boost is a broken or defective sealing ring. They said normally the sealing rings will outlast standard oil seals on other turbos by many times.
and yes, i want rails now so i can cruise in my car without it bucking like i'm 16 year old just learning to drive a clutch.
08-13-2011, 10:30 AM
#366
Well I have just discovered this thread and think I may be suffering the same problems! I'm running a Vortech though.
I'm getting a very lean spot between 3000 and 3500rpm while on part throttle.
Every thing was running fine but decided to upgrade my fuelling for extra safety. (Kind of wish I hadn't now)
A few weeks back I fitted AAM basic RFS, Walbro 255 and DW600cc injectors (all bought 2nd hand from here)
I ditched the SST box and changed to Uprev. On the drive home from the tuner post Uprev, when I was cruising on the motorway, I noticed it was hesitant when accelerating between 3k and 3.5k on part throttle. I have an AFR guage (fitted to the 2,4,6 bank) and this was showing 17:1 +.
I could accelerate through it in lower gears and not notice it so much but it was still there.
I went back to the Tuner and he had a tweak on the part throttle areas of the map but we couldn't get it to replicate the issue and all seemed fine. But driving home again after about 50 miles of sitting at around 3k in 6th the problem was back!
Over the last few days it got steadily worse to the point where it sounded a bit like a misfire even when revving with no load. This obviously worried me and spoke to my tuner.
I pulled the plugs and did a compression test to be safe and it was fine. The plugs are in reasonable condition but show some signs of running lean.
I sent the injectors for testing and one of them was supplying about 30% less fuel than the others and cleaning hasn't solved it. Obviously this is a problem that needs sorting but after reading this thread I'm not convinced it was my only problem.
Would a faulty injector only show up for a few hundred revs and work fine the rest of the rev range? Or is this a separate problem?
My RFS set up is including the two OEM dampeners in their stock locations but due to my Kinetix SSV being in the way of the bulkhead I've had to locate the FPR by the brake reservoir See pic), this means that the hose to it is about 3 times longer than the supplied one.
Could this extra length in the pipe be compounding the dampening issues?
It does sound like this may have been my original problem and that this had led me to find the injector going bad.
What are your thoughts?
I'm getting a very lean spot between 3000 and 3500rpm while on part throttle.
Every thing was running fine but decided to upgrade my fuelling for extra safety. (Kind of wish I hadn't now)
A few weeks back I fitted AAM basic RFS, Walbro 255 and DW600cc injectors (all bought 2nd hand from here)
I ditched the SST box and changed to Uprev. On the drive home from the tuner post Uprev, when I was cruising on the motorway, I noticed it was hesitant when accelerating between 3k and 3.5k on part throttle. I have an AFR guage (fitted to the 2,4,6 bank) and this was showing 17:1 +.
I could accelerate through it in lower gears and not notice it so much but it was still there.
I went back to the Tuner and he had a tweak on the part throttle areas of the map but we couldn't get it to replicate the issue and all seemed fine. But driving home again after about 50 miles of sitting at around 3k in 6th the problem was back!
Over the last few days it got steadily worse to the point where it sounded a bit like a misfire even when revving with no load. This obviously worried me and spoke to my tuner.
I pulled the plugs and did a compression test to be safe and it was fine. The plugs are in reasonable condition but show some signs of running lean.
I sent the injectors for testing and one of them was supplying about 30% less fuel than the others and cleaning hasn't solved it. Obviously this is a problem that needs sorting but after reading this thread I'm not convinced it was my only problem.
Would a faulty injector only show up for a few hundred revs and work fine the rest of the rev range? Or is this a separate problem?
My RFS set up is including the two OEM dampeners in their stock locations but due to my Kinetix SSV being in the way of the bulkhead I've had to locate the FPR by the brake reservoir See pic), this means that the hose to it is about 3 times longer than the supplied one.
Could this extra length in the pipe be compounding the dampening issues?
It does sound like this may have been my original problem and that this had led me to find the injector going bad.
What are your thoughts?
Ok then, I have now replaced my injectors with some brand new DW600s and the problem is still there. It's less severe than it was but still there.
Its still between 3000 and 3500 rpm at part throttle, most noticeable in 5th and 6th but I can replicate it in 3rd and 4th. Also, when accelerating in cruise control it's very prominent.
Car is hesitant at 3k and the AFR sits 15.8 to 16.9 then between 3300 and 3500 AFR rapidly falls to 13 ish and the car starts to pull.
I'm really beginning to think its this damper problem and will be looking to add a 3rd , ala MX.
Would altering the Fuel pressure change this in any way? Is it safe to try or would I need a retune once its altered? I just wondered if the extra/less pressure on the spring in the FPR would help dampen it down a bit.
08-13-2011, 03:47 PM
#367
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If the aam removed all the stock dampers then yes that could be the issue. it's odd that it only does it in higher gears. My dip happens at any gear with a certain load on the engine at a certain rpm. Always that set load and rpm across all gears.
Your ranges sound different than the ones we are experiencing which sounds like the tuner should be able to just add fuel in those areas.
fuel pressure really won't change it much so "less pressure on the spring" wouldn't alter this. I've tried many ranges of fuel pressure and nothing changed it. It's a resonance that the FPR can't remove.
Your ranges sound different than the ones we are experiencing which sounds like the tuner should be able to just add fuel in those areas.
fuel pressure really won't change it much so "less pressure on the spring" wouldn't alter this. I've tried many ranges of fuel pressure and nothing changed it. It's a resonance that the FPR can't remove.
08-14-2011, 02:33 AM
#368
If the aam removed all the stock dampers then yes that could be the issue. it's odd that it only does it in higher gears. My dip happens at any gear with a certain load on the engine at a certain rpm. Always that set load and rpm across all gears.
Your ranges sound different than the ones we are experiencing which sounds like the tuner should be able to just add fuel in those areas.
fuel pressure really won't change it much so "less pressure on the spring" wouldn't alter this. I've tried many ranges of fuel pressure and nothing changed it. It's a resonance that the FPR can't remove.
Your ranges sound different than the ones we are experiencing which sounds like the tuner should be able to just add fuel in those areas.
fuel pressure really won't change it much so "less pressure on the spring" wouldn't alter this. I've tried many ranges of fuel pressure and nothing changed it. It's a resonance that the FPR can't remove.
Regarding it being in the higher gears, it is there in the lower gears, its just that its much less noticeable because the revs climb through that range much quicker.
When I first had the problem my tuner did add more fuel in the relevant cells but it made little difference - although we could not get it to replicate the problem on his dyno (Hub dyno) it was still there when I drove on the road afterwards.
I haven't had it tuned again since changing the injectors, but it generally runs a bit richer now due to all the injectors actually supplying the same amount of fuel so I feel this probably why its not quite as lean as it was before.
I have a spare fuel rail and damper so if I can get another rail adaptor I would like to try adding a 3rd damper as mx did just to eliminate it.
If this isn't my problem. what else could it be?
08-14-2011, 07:46 AM
#369
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I still have the 2 stock dampers in the stock locations but the FPR is located where the brake reservoir is so the connecting hose is about 3 times longer than the supplied one, I wonder if this is compounding the issue.
If this isn't my problem. what else could it be?
If this isn't my problem. what else could it be?
length of the hose wouldn't really affect the resonance. You have 2 dampers so it really shouldn't have an issue. Mine worked perfectly on a basic return with only 1 damper on it but as soon as i went to a stage 3 and lost all dampers mine went to hell.
It sounds to me like it just needs to be street tuned. Roller dynos suck at doing the vac map because they can't hold a constant load on the engine like inertia dynos can. I would find those cells in a street tune that are causing issues and isolate them and start adding fuel in that area and blending it with the areas around it. Doing it on a roller dyno wouldn't be very helpful since you will be accelerating through the bad cell pretty fast and not be able to assess it fully.
street tuning or inertia tuning on the vac map is crucial for a nice smooth throttle. That's why i like DD dynos.
08-15-2011, 08:25 AM
#370
pretty sure the aam basic kit also eliminates one damper on the rear of drivers side rail.
MX's experience was that needed more than stock dampers. I talked to one shop that was having a problem a returnless car in the same spot, all factory dampers still in place. There doesnt seem to be much a pattern here other than the less dampers the more likely.
MX's experience was that needed more than stock dampers. I talked to one shop that was having a problem a returnless car in the same spot, all factory dampers still in place. There doesnt seem to be much a pattern here other than the less dampers the more likely.
08-15-2011, 06:32 PM
#373
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ya, i datalog and tune my haltech myself too. Car should be up and running this weekend since the engine is already back in it.
I'm still waiting on word with what to do about the rails though charles. You said to wait until rich had his figured out before buying these new ones.
I'm still waiting on word with what to do about the rails though charles. You said to wait until rich had his figured out before buying these new ones.
08-16-2011, 07:04 AM
#375
i had the problem with 1200ccs on the 1st build. same with the ID2000s before the TB lost its calibration when we unplugged the stock ECU to reflash the idle. APP, etc is fine.
The hesitation wasnt there around the 2400-2700 range when I test drove the car after the new rails. But like said, i didnt have a chance to take any logs. Soon though.
The hesitation wasnt there around the 2400-2700 range when I test drove the car after the new rails. But like said, i didnt have a chance to take any logs. Soon though.
Last edited by str8dum1; 08-16-2011 at 04:01 PM.
08-19-2011, 12:03 PM
#378
sorry, I know you have been patient. The rails are here and anodized... just actually i have a batch of the sealing washers for the fittings that go in on the way here so I cannot ship the rails just yet... I ran out of the washers this week, went thru the last of them faster than i expected. Not to mention, more than half of this batch of rails is going back to the anodizer tomorrow because they somehow managed to scratch up all the long ones after anodizing... a few sets have shipped from regular fuel system kit orders but i am down to 1-2 acceptable sets until i get them back again later in the week. but no washers now 
08-22-2011, 11:51 AM
#380
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I have all the time in the world. Still working out bugs on this new engine so i'm in no rush. I just didn't want to hold up my order if you had a slew of them and wanting to make some coin in your pocket. Whenever you are ready just let me know charles.