Spent 4 hours on the dyno, did about 27 pulls, and got absolutely nowhere with the car.
I tuned it perfectly with just 3 runs down the 1/4 mile in Montana, altitude change moving to Illinois screwed everything up, started over from scratch and went to the Dyno since there's one very close to me unlike where I used to live.
I know that I have more than enough fuel. 750cc injectors, return line, external walbro 255 running in series with my stock in tank pump. Super 20G turbo. I had fuel pressure set to 58psi static, injectors are scaled properly in the tune, idle and part throttle are perfect. Started with Stage 2 code as a base. Got the AFR at 11.5:1 at WOT until 5K RPM then it would jump up to 15:1. Tried adding fuel above 5K RPM, nothing changed. Increased VE values by as much as 50% above 5K, and still nothing changed.
Decide to hook the RRFPR up and go for 1:1, adjusted the tables for that, car did not want to idle at all after doing that (too lean), did another pull, hit 286whp and 302ft-lbs of torque at 4400RPM with 18psi, AFR pegged 10:1, right at 4500RPM sputtered (even richer, killed it), black smoke, so we shut it down. Went in, removed a bunch of fuel, added a little around idle, car wouldn't stay running, couldn't get another pull like that.
Went back to what I started with, static 58psi fuel pressure, flashed it again, car started right up and ran just fine, but still stuck with not being able to get above 5K RPM without it being too lean.
WTF am I doing wrong here? Like I said, nailed it last year at a higher altitude just tuning it at the track. I wasted so much time and money on the dyno today and have absolutely nothing to show for it. Couldn't drag race today either because of it.
I'm so pissed off right now, I did nothing but move 1400 miles away and drop almost 3000 ft in elevation. I've been tuning PT Cruisers for some guy in Germany via e-mail with 0 problems, awesome results, but my own car is being a bitch!
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One of a kind custom turbocharged 2004 Chrysler Sebring LX Sedan
.:CarDomain:.
13.5 @ 102mph
You need to fix the tune up to run boost referenced. You are probably losing static pressure above 5k. I have seen it happen many times. Need to adjust the returnless compensations, and then it will run just fine.
You need to fix the tune up to run boost referenced. You are probably losing static pressure above 5k. I have seen it happen many times. Need to adjust the returnless compensations, and then it will run just fine.
Yup I'm sure you're right, and I think I found out what the problem was. When we put the boost source back on the RRFPR (dyno was tapped in here since I had it capped and wasn't using it), we put the check valve on backwards.
I just thought about it while I was watching TV with the family, ran out to the garage, reversed the check valve, car started and idled with no problems whith the RRFPR connected to boost source this time, did a test run (hooray for living in the middle of corn fields in Illinois), pegged 10:1 AFR as soon as I got into boost. It seems the RRFPR did not like seeing vacuum (I tried it with the check valve removed all together at the dyno too), as soon as I hooked it up, it dropped 20psi and the car would stall out, would not want to start back up. Raised the pressure and tried it again, same thing. Now with the check valve facing the right direction, pressure is static until I hit boost, then it raises.
Going to re-flash with it setup for RRFPR and reset the VE table back to baseline, should run pretty good now.
The FPR should be able to see vacuum. Ideally, you want it to, to give true 1:1 rate under all conditions.
Gotcha... this was never installed correctly, just another example of something I should have done myself, instead of letting some crappy shop do it, and it's all wrong.
From the BEGi FPR manual:
Quote:
Check Valves
Two functions are accomplished by the check valve. One, the simple plugging of a small vacuum/boost leak. Second, vacuum is required
to pull the pre-load spring under the rising rate center screw away from the valve so thus reverting the regulator control to the one-to-one
side. Stock fuel pressures are then achieved under manifold vacuum conditions. The check valve white end attaches to a short segment
of vacuum hose, and the hose plugs onto the 5/32 hose barb attached to the needle valve. This allows venting the boost signal for
adjustment, but will seal under vacuum. The check valve blows off into the atmosphere, do not hook it to the manifold or anywhere else.
The check valve was installed between the manifold and the FPR. Explains a lot.
Never heard of a FPR using a check valve in that way. That may be listed for some specific application. The proper way is to get a manifold signal (boost & vacuum), and go straight to the FPR. That will give you the 1:1 reference you are looking for.
Never heard of a FPR using a check valve in that way. That may be listed for some specific application. The proper way is to get a manifold signal (boost & vacuum), and go straight to the FPR. That will give you the 1:1 reference you are looking for.
I got it figured out, but I have a feeling the issue wasn't losing pressure at that RPM. Take a look at my other post in another thread here called "confusing problem". After looking at all my dyno charts again, the problem isn't exactly as I described it here. I was going off of memory on the last 2 pulls only on this thread.
This has turned more into chasing a fuel system issue than a tuning issue, it's a little of both I suppose. I'm still not getting anywhere.
Thanks a ton Neil for your comments keeping me on track.
I'm really having a hard time getting the car to run correctly with the FPR hooked up the way it should be. In fact, idle and part throttle are just awful if the fuel pressure is too much lower than 58psi under those conditions.
Here's what I've tried so far:
1) Set fuel static to about 45psi (easier than trying to find where 43.5psi is on my fuel pressure gauge), modify VE table until idle is stable at that pressure, raise fuel to 60psi (eaiser than trying to find 58), hook vacuum/boost reference up to FPR for 1:1, fuel pressure drops under vacuum, and raises under boost, so everything is working correctly there. After doing this, idle wants to sit at 16 to as high as 18:1 AFR, then will eventually drop into the 15:1 range. Part throttle sucks, almost stalls, and where this happens is completely random, can't get it to duplicate it. I also notice that the coasting fuel shutoff does not kick in. WOT is too rich, it's like hitting a wall... black smoke out the tail pipe, have to let off immediately after getting on it.
2) Set fuel pressuer to 60psi, hook up FPR to boost reference only. Use S2 VE table as baseline, idle and part throttle are absolutely perfect, car starts on the first try, very smooth, very responsive. WOT is too rich, just like under #1, however I did not get to the point of pulling fuel out in the tune. so it may work a lot better after pulling some fuel in the tune.
Now the only thing I haven't tried, is raising the fuel pressure to the point where it would drop to 60psi under vacuum (so raise it up closer to 70psi before attaching the vacuum/boost source). Is that what I should be going for? I did not think that was the correct way of doing it, since I would be seeing 90+psi of fuel pressure under boost, which just seems way to high for me.
Is there a reason I should not set the fuel to 60psi and hook the FPR up to a boost only source? Doing that at 23psi boost I should see 83psi fuel pressure where the external walbro 255 would be flowing ~41gph and the intank 190 would be flowing ~22gph @ 12v. All of which is way more than enough fuel flow for the 350-400whp range that 23psi of boost should put me in. It seems like setting it up this way and pulling fuel from the tune would be the easiest way to go, since I can already get perfect idle and part throttle doing this.
Mathmatically I don't see why a static fuel pressure of 60psi would have been running out of fuel flow with the amount of boost I was running when I first ran into this problem. 750cc injectors rated at 43.5psi running at 60psi = 880cc, even if the pressure dropped to 50psi in the upper RPMs for whatever reason, at 50psi they'd be 804cc. Assuming 20% drivetrain loss with my auto, that's still enough injector for 391whp (also assuming the fuel pressure was dropping), and the 18psi of boost I was running should only put me in the low 300whp range at best. Stock pump alone would have been putting out 32gph at 60psi or 36gph at 50psi, add the 255 on top of that, another 49gph at 60psi or 53gph at 50psi.
I'm really hoping it's not a leak or clog as Neil pointed out in another thread it could be. Trying to rule those out the best I can. I don't have the tools, time, or money to fix a leak or clog right now. So messing with the FPR and tune is the best I can do for right now. The stock sock filter in the tank with the stock pump is brand new, had it replaced when I started this project, only have 4,000 miles on the car since then. Stock pump has 44,000 miles, external walbro 255 has less than 4,000 miles, I ran on just the stock pump for quite some time before adding the external 255. No reason any of those parts should be bad with as little useage as they've seen.
Ok, I thought you had this figured out so I never posted on it... A couple things I was thinking about:
1. Is your return line returning back into your fuel canister?
2. I thought everyone ran return lines with BOOST reference only and not vacuum/boost. I know that Neil just stated otherwise, but wasn't that what everyone was doing before?
3. Are the values in your SCT setup correctly for a return line?
1. Is your return line returning back into your fuel canister?
Not sure... stupid shop I had doing the work for me out in MT did this, they had the car for 8 months and didn't finish it, but the return line was part of the work they actually did get done. Like I said, had the car running great all last year, parked it for the winter, moved to IL, now having problems.
Quote: Originally Posted by Mana4real
2. I thought everyone ran return lines with BOOST reference only and not vacuum/boost. I know that Neil just stated otherwise, but wasn't that what everyone was doing before?
Maybe everyone with an SRT-4 does... but remember this is an NA Sebring 2.4L rebuilt with SRT-4 internals. For NA to Turbo conversions you usually run 1:1 with vacuum/boost source... Since I have everything setup nearly identical to an SRT-4, I don't think I really need to do that.
Quote: Originally Posted by Mana4real
3. Are the values in your SCT setup correctly for a return line?
Yes. Returnless fuel table is all set to 1 for every pressure rate above 0.
I think the problem may actually be with the FPR itself. I decided to do some more testing with it hooked up to boost reference only. When I went to raise the pressure back up to 60psi, the pressure didn't want to increase. Tried turning the adjustment the other direction, and it wouldn't decrease either. After playing with it for a couple minutes, the pressure finally responded when I turned the adjustment bolt. I placed an order for a rebuild kit, and will rebuild the FPR when it gets here. I haven't had time to take the FPR apart to see if it really needs it, but for $30 since I'll be taking it apart anyway, may as well rebuild it at the same time. The last time I had a problem with this FPR (last summer), one of the metal shims inside of it had torn and the pressure shot up to 100psi, could not be lowered. The shim was no thicker than common alluminum foil, so I cut a piece of foil to size and replaced it, it worked perfectly all last year. Did not replace the diaphrams or spring at that time, so this time I will do a full rebuild with replacemant parts from the manufacture.
I also ordered a restrictor ($3) just in case. I can use that to lower the amount of boost the FPR sees so the fuel pressure won't rise as fast. Today with it set to 60psi and hooked up to boost reference only, I pulled 25% fuel from 1.05 pressure ratio on up across the entire VE table. AFR was still showing 10.3:1 at WOT, but this time it didn't instantly sputter and spit out black smoke... took a good 5 seconds of WOT before it did that.
25% already seems like a lot to be pulling from the VE table, and it will need a lot more pulled before it is lean enough. Is there somewhere else I should be making an injustment? Injectors are scaled properly, idle/part throttle are great, returnless fuel is set to a value of 1 for every cell greater than 0 pressure as I already mentioned.
Which tune are you basing this off of? Want to send it to me to have me have a look at it this evening (if I can access it)? I have to look at someone elses as well... We have talked before... Remember we were locating a map sensor for you? I have an idea on some stuff, but it's easier to look at and then respond.
Or you can call me at work for the next hour till I go to lunch... 1-800-683-1646... Just ask for Matt
Which tune are you basing this off of? Want to send it to me to have me have a look at it this evening (if I can access it)? I have to look at someone elses as well... We have talked before... Remember we were locating a map sensor for you? I have an idea on some stuff, but it's easier to look at and then respond.
Or you can call me at work for the next hour till I go to lunch... 1-800-683-1646... Just ask for Matt
Yeah I remember, ended up having to take the dremel to the MAP sensor to get it to work.
I'm at work right now, so can't even look at the tunes from here. I don't know if I still have your e-mail address, PM it to me. IIRC the part number I'm working off of is 048600AF (Mexican Turbo Stratus NGC1). I copy and paste the Stage 2 VE table into it to use as a base, and use the '05 Stock fuel injector tables to scale injectors since that table has the same amount of cells as the code I'm using. There's a lot more into to make this car run smoothly, but those are the basics. Mex Turbo Strat NGC1 code + some PT Stage 1 values + Some '05 SRT4 values + Some Stage 2 SRT-4 values + some Stage 3 SRT-4 values = smooth baseline for this car.
Yeah I remember, ended up having to take the dremel to the MAP sensor to get it to work.
I'm at work right now, so can't even look at the tunes from here. I don't know if I still have your e-mail address, PM it to me. IIRC the part number I'm working off of is 048600AF (Mexican Turbo Stratus NGC1). I copy and paste the Stage 2 VE table into it to use as a base, and use the '05 Stock fuel injector tables to scale injectors since that table has the same amount of cells as the code I'm using. There's a lot more into to make this car run smoothly, but those are the basics. Mex Turbo Strat NGC1 code + some PT Stage 1 values + Some '05 SRT4 values + Some Stage 2 SRT-4 values + some Stage 3 SRT-4 values = smooth baseline for this car.
Ok, I am not sure if I can look at that file, but I will try. I am at work and I don't have my laptop with me, so it will be this evening before I can look at it (I am on the west coast). Mana4real@yahoo.com is my addy.
Ok, I am not sure if I can look at that file, but I will try. I am at work and I don't have my laptop with me, so it will be this evening before I can look at it (I am on the west coast). Mana4real@yahoo.com is my addy.
Just let me know what tables you want to see and I can take a screen shot of them... it's very similar to the stock '04 SRT-4 code, just has slightly different values in a few tables, but for the most part the tables are all the same size.
Returnless is your issue. The cars that are not running boost/vacuum reference are doing it out of what I call 'lazy calibrating'. NGC PCM lets you get away with that to some degree. I like it right To start, set all of your retunless values to 1. The scale on that table inside of Advantage is wrong, and what you interpret to be above 0 may indeed be opposite what you think. Get rid of the restrictor, and make sure nothing is "branched" out from the line feeding the FPR. You want it to respond as quickly as possible, and without error. Sounds like you still have Cat Overtemp Enrich turned on, and your injectors are not modeled right. Pull the vacuum line off the FPR, and set the pressure to 58psi. Then hook the vacuum line back up.
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Can't get fuel above 5K
To start, set all of your retunless values to 1. The scale on that table inside of Advantage is wrong, and what you interpret to be above 0 may indeed be opposite what you think. Get rid of the restrictor, and make sure nothing is "branched" out from the line feeding the FPR. You want it to respond as quickly as possible, and without error. Sounds like you still have Cat Overtemp Enrich turned on, and your injectors are not modeled right. Pull the vacuum line off the FPR, and set the pressure to 58psi. Then hook the vacuum line back up.
Linear Mode
