Lean Spot At ~2400 RPM...What the?
07-20-2010, 08:50 AM
#101
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sounds like a bad FPR or maybe something clogging the return.
does aam use a return correction like CJM? i don't think they do but i'm not sure.
Your return should go down to where the oem fpr is. If it doesn't you'll have issues. Check whatever aam gives you to make sure nothing is clogged on the return side. Sounds like something might have clogged it up causing it not to return fuel properly.
all else fails buy the cjm return correction for like 60$ and use that since it doesn't have any issues.
does aam use a return correction like CJM? i don't think they do but i'm not sure.
Your return should go down to where the oem fpr is. If it doesn't you'll have issues. Check whatever aam gives you to make sure nothing is clogged on the return side. Sounds like something might have clogged it up causing it not to return fuel properly.
all else fails buy the cjm return correction for like 60$ and use that since it doesn't have any issues.
Last edited by binder; 07-20-2010 at 11:44 AM.
07-20-2010, 09:27 AM
#102
not sure what you are talking about.....
THE CJM setup uses the aeromotive FPR. It has nothing to do with the intank piece shown below
This is just a machined spacer. Its the same as hollowing out the stock in-tank regulator (the part that the OP drilled when he went back to stock).
He doesnt use the intank OEM FPR with his RFS, he uses that blue spacer.
THE CJM setup uses the aeromotive FPR. It has nothing to do with the intank piece shown below
This is just a machined spacer. Its the same as hollowing out the stock in-tank regulator (the part that the OP drilled when he went back to stock).
He doesnt use the intank OEM FPR with his RFS, he uses that blue spacer.
Last edited by str8dum1; 07-20-2010 at 09:34 AM.
07-20-2010, 11:40 AM
#103
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not sure what you are talking about.....
THE CJM setup uses the aeromotive FPR. It has nothing to do with the intank piece shown below
This is just a machined spacer. Its the same as hollowing out the stock in-tank regulator (the part that the OP drilled when he went back to stock).
He doesnt use the intank OEM FPR with his RFS, he uses that blue spacer.
THE CJM setup uses the aeromotive FPR. It has nothing to do with the intank piece shown below
This is just a machined spacer. Its the same as hollowing out the stock in-tank regulator (the part that the OP drilled when he went back to stock).
He doesnt use the intank OEM FPR with his RFS, he uses that blue spacer.
i see what could be the confusion. i'll edit my above post. i had an error in typing.
Last edited by binder; 07-20-2010 at 11:43 AM.
07-20-2010, 01:22 PM
#105
I was using the CJM stage 0 return fuel system, which included that piece that Str8 posted above. I don't have an AAM return system. The CJM return system uses an Aeromotive FPR, which I believe may be the cause of my problems. I will take it apart to investigate. But as of right now, the car is working a whole helluva lot better without a fuel return system period.
07-20-2010, 02:46 PM
#106
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The last 3 ppl i had pm's from were about aam return fuels so my brain was backwards.
ya, so i guess check to see if anything is clogged. What was the base fuel pressure set at on your regulator? Something is obviously wrong between the rails and the pump on the return side. Maybe an internal leak of the blue return hose?
07-20-2010, 02:59 PM
#107
Another thing you should fix because it could be causing idle & low RPM problems is the non functioning evap valve.
Has the evap canister ever been flooded with fuel ?
Has the evap canister ever been flooded with fuel ?
07-21-2010, 05:27 AM
#108
I think I figured out the root cause of all of this nonsense.
Remember how I said that the guy I bought the FPR from had taken the top off and painted it black? Well last night I took it apart and guess what I found. Apparently he also painted the inside of the top cover. This wouldn’t be an issue except for the fact that the metal portion of the diaphragm which the spring acts against is a relatively close fit to the inner diameter of the top cover, which is anodized aluminum. Anodizing is great because it is a smooth, hard coating that is rather slippery. However when you add a thickness of soft, sticky paint to close fitting parts they tend to not move like they are supposed to. There were two spots where the paint was partially rubbed off from the diaphragm piece trying to move. My guess is that although it was still performing the 1:1 rise function like it was supposed to, the paint interference was not allowing it to handle the small resonant vibrations in the fuel system.
At least that’s what I am hoping. I removed the paint and reinstalled the regulator last night. As soon as my fuel bucket o-rings come in (stupid things – why do they expand so much?) I am going to hook up the return again and test drive it.
Remember how I said that the guy I bought the FPR from had taken the top off and painted it black? Well last night I took it apart and guess what I found. Apparently he also painted the inside of the top cover. This wouldn’t be an issue except for the fact that the metal portion of the diaphragm which the spring acts against is a relatively close fit to the inner diameter of the top cover, which is anodized aluminum. Anodizing is great because it is a smooth, hard coating that is rather slippery. However when you add a thickness of soft, sticky paint to close fitting parts they tend to not move like they are supposed to. There were two spots where the paint was partially rubbed off from the diaphragm piece trying to move. My guess is that although it was still performing the 1:1 rise function like it was supposed to, the paint interference was not allowing it to handle the small resonant vibrations in the fuel system.
At least that’s what I am hoping. I removed the paint and reinstalled the regulator last night. As soon as my fuel bucket o-rings come in (stupid things – why do they expand so much?) I am going to hook up the return again and test drive it.
07-21-2010, 01:17 PM
#112
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dang
well i'm sure there is a way you can just solder a jumper wire with a connector on it and do hte same for the car side then just connect them. Prob better than buying a harness that i would guess is close to 500$
well i'm sure there is a way you can just solder a jumper wire with a connector on it and do hte same for the car side then just connect them. Prob better than buying a harness that i would guess is close to 500$
07-23-2010, 04:30 AM
#113
Ok now I am confused again. I cleaned all the paint off the Aeromotive regulator and re-installed the fuel return system. The lean spots are back, as bad as ever. So the paint was not causing the problem like I had hoped.
What is wrong with my fuel return system? Why has nobody else ever had this issue with a fuel return? Maybe I will send Phunk a PM.
I am getting sick of working on this effing car. I am seriously considering just ripping out the fuel return and calling it a day. I’m on a stock block anyway so I really don’t need it. The car ran 100x better without it.
What is wrong with my fuel return system? Why has nobody else ever had this issue with a fuel return? Maybe I will send Phunk a PM.
I am getting sick of working on this effing car. I am seriously considering just ripping out the fuel return and calling it a day. I’m on a stock block anyway so I really don’t need it. The car ran 100x better without it.
07-23-2010, 06:06 AM
#114
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Don't give up just yet, man. Definitely is a frustrating situation, but you'll get it figured out. Keep a cool head while your out there. I know how many times I've got myself in a bad mood trying to work under a car when things don't seem to work right.
I'm still subscribed to this thread, and I'll try to help any way I can. ...but I'm at a loss right now, too.
I'm still subscribed to this thread, and I'll try to help any way I can. ...but I'm at a loss right now, too.
07-23-2010, 06:44 AM
#115
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hmm, ya, talk to charles at CJM. Just call him directly and tell him what's going on.
It's obviously a problem with the return system so you have it narrowed that far down.
what did you have your base pressure set at on the regulator? Stock pressure is 51psi or so. I would leave everything in the car since you have it already there and bump the fuel pressure on teh regulator to 53 psi and see what that does for you. That's a quick and easy check.
If not then you need to check the return line flow (if it's restricted) and then see if there is a possible leak or restriction ni the blue line inside the tank and that blue spacer. If you removed it you should be able to check it with it out of the car pretty easily. If those both flow just fine and you have that worm gear clamp on the blue line nice and tight (so there are no internal leaks) then it's something with the regulator. Im' sure charles would send you another one to test out.
It's obviously a problem with the return system so you have it narrowed that far down.
what did you have your base pressure set at on the regulator? Stock pressure is 51psi or so. I would leave everything in the car since you have it already there and bump the fuel pressure on teh regulator to 53 psi and see what that does for you. That's a quick and easy check.
If not then you need to check the return line flow (if it's restricted) and then see if there is a possible leak or restriction ni the blue line inside the tank and that blue spacer. If you removed it you should be able to check it with it out of the car pretty easily. If those both flow just fine and you have that worm gear clamp on the blue line nice and tight (so there are no internal leaks) then it's something with the regulator. Im' sure charles would send you another one to test out.
07-23-2010, 12:33 PM
#116
Definately give me a call asap so we can work this out.
You are not the first to experience this issue... Although it's rare (you would be shocked to hear how many fuel systems we have sold since 2004!)
I apologize for your time spent on this issue and we will do whatever it takes to resolve the issue and make your RFS useful to you.
You are not the first to experience this issue... Although it's rare (you would be shocked to hear how many fuel systems we have sold since 2004!)
I apologize for your time spent on this issue and we will do whatever it takes to resolve the issue and make your RFS useful to you.
