Aeromotive 13109 & Fuel guage

[DSM90AWD]

another thing, my fpr does not hold pressure after being shut off. it will immediately drop to about 20psi when shut off and after about an hour it will be at 0psi.

Sounds like a classic case of the pump's outlet o-ring not seating correctly in the hood (first-hand experience with this).

Re/re the pump from the hood and if the o-ring is not damaged, add a dab of oil or petroleum jelly to the o-ring so does not bind/twist/tear when re-seating in the hood

**one also thing to note that if the top seal is bad, your fuel pump efficiency will be greatly diminished (much like a boost leak would hurt a turbo's performance)

 

[oldman]

i did the check last night and in fact did have the minutest (sp?) of leaks, i mean i had to sit there for a few seconds before the slightest bubble appeared. i went ahead and put some thread sealer on as suggested.

You're definitely luckier than me, mine started hissing as soon as I pressurize the intake. Did you also seal the vacuum fitting as well?

i have dsmlink so i fired the pump to set base (43.5) and then ate some dinner. came back out after 30 min or so and started the car, no difference, it still only pulls down to 39 (when i expect to see 34-36) with 18" vac. i do know i have a leak with the tb gaskets as my upper pipe also replaces the tb elbow, but i would not expect it to cause this much grief as the tb is on the opposite end of the intake and my boost gage shows 18" vac and is tied into the same line as the fpr. also it makes no difference if i go through the fps or tap off the mani.

First let's make sure you have the correct vacuum reading, does your boost gauge zero out when the car is off with the ignition at "on" position? If so, pressurize the intake and fuel system at the same time with the car off, make sure the ratio maintains 1:1 as you increases the intake pressure one psi at a time.

 

[FORMONTOYA]

Sounds like a classic case of the pump's outlet o-ring not seating correctly in the hood (first-hand experience with this).

yea, i realized that earlier today from searching that problem. just waiting on a paycheck to resolve a few issues with the car. but that should not effect the fpr not pulling down as expected which is the issue i can not figure out at the moment.

thanks,

jim

 

[FORMONTOYA]

You're definitely luckier than me, mine started hissing as soon as I pressurize the intake. Did you also seal the vacuum fitting as well?

yes, the instructions mentioned to seal the vac/boost port. do not ask me why i did not think about the adjuster screw...with no pressure the screw is sloppy as hell.

First let's make sure you have the correct vacuum reading, does your boost gauge zero out when the car is off with the ignition at "on" position? If so, pressurize the intake and fuel system at the same time with the car off, make sure the ratio maintains 1:1 as you increases the intake pressure one psi at a time.

yes, it is a spi 30-30 mechanical and it has always zeroed out. i will try to get at it this evening, but my wife has been wanting some "me" time since the last 2-3 weeks have been devoted to the eclipse. according to her, since it runs i should be done (but i can not convince her it will never be done).

thanks,

jim

 

[FORMONTOYA]

i just thought about something...the one thing that might be different about my fpr setup is instead of using a straight connector as supplied by the feed/return kit, i used a 90 deg fitting like this for the return back to the tank
http://www.parker.com/tfd/cat/pdffiles/C-Triple-Lok/c5ox.pdf
i would not think it would matter, but i thought i should throw that in there. and it will be this weekend before i get the tb gaskets needed to fix a boost leak and then i will try to narrow down the fpr issue after another leak test is compleat and am sure all other leaks are resolved.

jim

 

[scottsee]

my wife has been wanting some "me" time since the last 2-3 weeks have been devoted to the eclipse. according to her, since it runs i should be done (but i can not convince her it will never be done).

God I know what you mean!!

 

[FORMONTOYA]

as stated earlier, i have an aeromotive fpr that is not pulling down as expected. with base fp set at 43.5 hose off, hose on at 18 vac i expect to see 35-36 psi of fuel, however it only pulls down to 39 psi. it was suggested that the adjustment screw was leaking and to test by running pump at the same time do a boost leak test to confirm a 1:1 rise. i did this over the weekend.

a little history: car just came off jackstands first of dec after 11 months. of course i knew i had boostleaks and a non-sealing o-ring in the fuel pump as it would not hold pressure after pump went off. testing was done on a 40-60 deg day. vac/boost gage zeros out when shut off. using an air comp that will maintain steady 25 psi test. 255 r/w fp, aeromotive fpr with sbr ss feed and return lines, b&m fp non liquid filled gage. vac/boost gage is spi 30-30.

first test as is would only hold 9-1/2 psi.found several boost leaks and very minor leak at fpr adjusting screw. however with pump running during boost test the fpr rose to 52.5. about 1/2 psi low.

fixed all boost leaks and did a few boost tests and can now hold 25 psi for 25-30 sec before it starts to fall. ran fp check fp rise and it did go to 68.5...perfect.

next to the o-ring in the fp hat. i ended up twisting the first one so back at it. did a base check and it actually rose to just over 44 psi. that non sealing o-ring was worth about 1/2 psi fuel. no telling how much was being bypassed if i actually was boosting. however i could only suspect it would get worse over time if left unchecked.

base fp setting at 43.5, boost 25 psi and end up with a total 68.5 psi fp. and after all this i actually gained 2" vac to new 20" vac at idle, however my idle fp is still at 39 psi. i am totally stumped as to why the fpr does not pull down as suspected.

any other suggestions would be greatly appreciated. i have practically covered the whole engine bay with soapy water and can not find anything.

jim

 

[FORMONTOYA]

oh yea, it makes no difference if i run though the fps or tap straight off the intake mani.

jim

 

[daren_p]

I can't check at the moment but if I recall correctly, my base fp is set at 44 psi as well and at idle I see ~39 psi too. I don't think this is anything to be worried about. As for how your fpr is acting, going to ~20 psi as soon as you shut the car off then slowly droping to 0 psi over a few hours, mine does the same thing but 99% of the time the car starts right away like normal.

 

[oldman]

My goes down to about 33psi at idle when set to 43.5psi (my eprom is set to 43.5psi) with -21 inHG of vacuum so something is definitely not right. Have either of you tried setting it below 39psi with the vacuum off? Did you replace the stock return lines to -6AN? I remember reading while back that the 2G return line is as much a restriction as the fpr itself, something to look into. My pump also bleeds down to zero after several hours so my question for DSM90AWD is, does your pump hold pressure indefinitely? If so, I would need to check my pump o-ring as well.

 

[FORMONTOYA]

My goes down to about 33psi at idle when set to 43.5psi (my eprom is set to 43.5psi) with -21 inHG of vacuum so something is definitely not right. Have either of you tried setting it below 39psi with the vacuum off? Did you replace the stock return lines to -6AN? I remember reading while back that the 2G return line is as much a restriction as the fpr itself, something to look into. My pump also bleeds down to zero after several hours so my question for DSM90AWD is, does your pump hold pressure indefinitely? If so, I would need to check my pump o-ring as well.

i only replaced the rail feed and return to the fpr. the fpr to the tank is still factory. however i use a 90 deg fitting found here
http://www.parker.com/tfd/cat/pdffiles/C-Triple-Lok/c5ox.pdf
and hose adapter to connect to the hose. i have not tried to set the fpr any lower than the 43.5 base. i can check that after work. and i will try the straight fitting that came with the fpr, however i would end up relocating it if that solves the problem and that would suck.

darren_p: how is your fpr set up? fittings, connections, rail feed and return to fpr, back to tank?

and also my fpr holds base pressure for at least a couple hours as that is the last time i checked last night and it was good, but this morning it had bleed down to zero. did i screw up a second time?

jim

 

[daren_p]

I am using the factory return rubber line but I don't think this would be causing a problem as its a larger diameter then the metal line that goes back to the tank. Not sure the id of the rubber line but I know its a pretty good stretch to get it to fit over a -6 an barbed fitting. I didn't like the fit so went with a 7mm barbed fitting from aeromotive. As a side note when we first hooked up my buddies fpr on his 2g (using the stock return line) his interior defi fp gauge was reading about 5 psi high. We set his base fp to 44 (or so we thought) with this and the car was running so lean that the O2 sensor wouldn't cycle, so I would think we were actually seeing 39psi or less.

As far as my setup goes, its stock up to the fuel rail. Then I have a -6an adapter, a low profile 90, -6an hose, low profile 90, fpr, aeromotive -6an to 7mm barbed fitting (part # 15627, search summit for info, its $19.99), to return rubber line.

Iam using Earls ano-tuff swival fittings & their pro-lite 350 hose (I think their the most expensive fittings and hose but I wanted the black "sleeper" look)

 

[DSM90AWD]

so my question for DSM90AWD is, does your pump hold pressure indefinitely? If so, I would need to check my pump o-ring as well.

No, mine bleeds down slowly.

My gauge is also mounted off the fuel filter banjo (if that matters).

Just to note, do not use a 37* flare AN fitting for the FPR side of the fuel connection (hose side yes).

You should uses a non-flared AN thread as if you use the flared, it will bottom out in the port and artifically boost your base FP. Buddy was running 50psi base with his SupraTT pump before he realized his error

 

[oldman]

John, does your vacuum pull it down to where it should be at idle?

 

[DSM90AWD]

John, does your vacuum pull it down to where it should be at idle?

If memory serves yes. I'd go out and check again but car is in pieces right know as you well know

 

[oldman]

If memory serves yes. I'd go out and check again but car is in pieces right know as you well know

Still waiting for me to change your plugs for you?

 

[FORMONTOYA]

Have either of you tried setting it below 39psi with the vacuum off? Did you replace the stock return lines to -6AN?

got home last night and played with the fpr. with pump running i set the base at 37 with hose off. started car and it only pulled down to roughly 32-1/2 which is the same amount as it was dropping before (roughly 4-1/2-5 psi drop with 18"-20" vac).

from filter to rail: -6an ss line, rail to fpr: -6an ss line, fpr to tank: new stock size hose to stock hard line setup.

the fpr "kit" had a straight fitting for the return back to the tank and i put a 90 deg connector because of fpr location. also swapped the 90 for the straight as a test and it made no difference.

i guess i will call aeromotive later today to see what their tolerance is for this fpr. hopefully i am just being a little to anal about this whole thing because it does rise 1:1 properly.


jim

 

[FORMONTOYA]

of course me in blue

Hello,

I have a 98 Mitsubishi turbo Eclipse and am using your 13109 fpr. Fuel setup is as follows: Walbro 255lph re-wired pump, stock lines up to fuel filter, stock fuel filter (new), -6AN SS braided line from filter to fuel rail, -6AN SS braided line from rail to 13109 fpr, 90 deg fitting as found here http://www.parker.com/tfd/cat/pdffiles/C-Triple-Lok/c5ox.pdf to -6AN hose barb adapter to stock return hose and hard line back to tank.


The problem I am having is that it does not pull down under vac as I would expect, and after reading this statement under you FAQ Note: the ratio of 1:1 is measured in PSI. When looking at a vacuum gauge, it is normally calibrated in “HG or inches of mercury. It takes roughly 2”HG to equal 1 PSI. So when the vacuum gauge reads 10”HG, with the engine at idle for example, fuel pressure will drop 1/2 of that or 5 PSI. confirms my thought that I should see about 1psi drop for every 2"vac. A base fp of 43.5psi only pulls down to roughly 39psi. The problem as that at idle running 18"vac I only see a 4-1/2-5psi drop. However I can do a simulated "boost" test, running fuel pump with car not running and pumping my test pressure of 25psi in the intake track, and I do see the expected 1:1 rise in fp. I have a SPI 30inHG-30psi gage tapped into the same line as the fpr which is tapped direct to the intake mani. The gage does "zero" out with the car off. I have fixed my vac and boost leaks and can hold the 25psi test pressure for roughly 30 seconds before the pressure starts to fall.


My question is what is the tolerance of this fpr as far as "pull down" at vac ("roughly 2"HG to equal 1 PSI", what is roughly)?

Am I good or do I need another fpr?

Any suggestions as to what the problem might be?


Any help would be greatly appreciated.

Thanks,




Jim,

We spoke at length by phone today and you were going to perform some tests. Let me know how this goes. Good luck and thanks for choosing Aeromotive!

Brett Clow

Aeromotive Tech Dept

Brett,

I finally got around to testing as we discussed earlier. I went to a shop that a friend works at that had a vacuum pump and tested the fpr, of course it "bench tested" as it should. However, on the car, it would pull down as expected up to about 9-10" vac with about a 4-1/2-5 psi drop in fp. Then it acted like it hit a brick wall from about 10" vac. As stated earlier, it does rise 1:1 on boost properly. I checked the return line back to the tank and found no kinks, dents or otherwise problems with it. However, upon further inspection of the fuel pump assembly I noticed that the short tube inside the tank "flange" appears to drop down from the main 5/16" line to about a 1/4" line. I can only guess that this is my bottleneck, but would think that would affect the 1:1 rise and not the "pull down" on vacuum. The only thing I have not done is to buy a 5 gallon gas can and run the return to it instead of back to the tank to confirm this. With my fuel management system I am able to adjust global and dead time of my injectors, and also have control over the wot characteristics. With the difficulty of re-working the fuel pump assembly and/or bumping up to a 3/8" line from the fpr to the tank, I will hit a forum specific board for my car later today to confirm that running "as is" will not create any problems other than maybe a little poorer gas mileage. As mileage is not really a concern for me since the car is just a "toy" taken out of the garage on nice days, I will just add a check of the fuel system to my "to do" list of regular maintenance to assure it continues to operates as it does now.

I really appreciate your time and trouble to discuss my issue and help me resolve this problem even though it was not related to your product.

Thanks again,



James,

Glad to assist. If you are referring to the line in the tank that connects the pump outlet to the bulkhead, it would not effect the low side pressure capability of the regulator, either by adjusting the stud for lower base, or applying vacuum to achieve the same.

You will find the issue is in the return line. Do run the test where you install a temporary –6 line from the regulator return port into a fuel can and let me know what you find.

Brett Clow

Aeromotive Tech Dept



Brett,

Actually I am referring to the low pressure return line from the fpr to the tank going from what appears to be 5/16" from the fpr to the outside of bulkhead, then switches to 1/4" inside the tank at the bulkhead. The high pressure outlet appears to be about 3/8" to the bottom of the fuel filter. Then it goes from top of filter with -6AN (Earls' 45, SS braided hose, 45) to the rail, -6AN (reg 90, SS hose, reg 90) from rail to the fpr, then 5/16" (90 ORB to 5/16" 37 deg flare/37 deg flare to 5/16" hose barb fitting ~12" gas hose, tube to vicinity of tank, ~12" gas hose, bulkhead) return to tank. I will go ahead and get a 5 gallon gas can this weekend and hook up the 3/8" version I also have to see what happens. I do have a feeling that this will solve the problem. Although as stated, this might be a bigger job compared to the gains if the only downside is that I have a little poorer gas mileage at idle and cruise. I am still waiting for several opinions as to the effects of this as my real concern is that it rises 1:1 on boost. Which it does without a problem.

One thing I can say is that I do not have a problem with turning the base pressure down as low as 25psi as that is as far down as I went during testing. No matter where I set the base pressure it would only drop 4-1/2 to 5psi with 18-20" vac which really surprises me because I would expect it to be somewhat linear with different base settings.

Thanks again,



James,

Well, it makes no sense to me that you could change the adjusting stud position, lowering fuel pressure to 25 psi for example, then set the base to 34 psi and apply 18” HG and not see the pressure drop back to 25 psi. Let me know what you find with the fuel can test.

Brett Clow

Aeromotive Tech Dept

well i did the return to a bucket and the fpr operates as expected pulling down 1psi per 2" vac using the stock 5/16" return line setup. the only thing i can figure is inside the bulkhead the line turn into what appears to be a 1/4" tube about 4-6" long inside the tank. the fpr operates on the car correctly down to about 9-10" vac then it hits a brick wall and will not move any farther. of course on boost it operates fine, 1:1 on boost up to 30psi.

my question, i am using dsmlink and i can get stable ltft lo and mid setup good, what is the downside to leaving "as is" other than maybe a little less gas milage?

 

[FORMONTOYA]

basically the car runs and acts great except that it hits a brick wall at roughly 10" vac were it does not pull down any lower than 4-1/2 to 5 psi fp. it operates great from 10" vac up to a tested 30 psi boost at 1:1. other than 1-2 less mpg, what is the downside of this?


jim

 

[oldman]

Let me try and understand this correctly.

1. When the return line is run to a seperate container with everything else connected to the car as it should, it's pulling down 8-9 psi at idle like it should. As soon as you reconnect the return back to the stock lines which runs back to the tank, the problem re-appeared. Is this right?

2. You are able to physically turn the pressure down via adjustment screw below 25psi, is this right?

If the above two conditions were true, then nothing makes sense . Condition #1 clearly indicates the stock return fuel line being the problem but #2 immediately disproves #1. I don't know, I have to think about this one. Good job on trying to get to the bottom of this and continues to update us with such detail, most would have given up long ago like daren_p. Please correct me if I misuderstood you in 1 & 2.

 

[FORMONTOYA]

Let me try and understand this correctly.

1. When the return line is run to a seperate container with everything else connected to the car as it should, it's pulling down 8-9 psi at idle like it should. As soon as you reconnect the return back to the stock lines which runs back to the tank, the problem re-appeared. Is this right?

yes. as a matter of fact, i have gone as far as to put a hose to seperate tank/bucket at the point where the hard return line ends at the gas tank and the fpr will pull down as expected. but when i hook it back up to the gas tank it will only pull down 4-1/2-5psi. when i look at the bulkhead/flange the line goes from ~5/16" to what really apears to be about ~3/16", i am just being generous with saying it is ~1/4" inside tank.

2. You are able to physically turn the pressure down via adjustment screw below 25psi, is this right?

yes. and i know, i can not figure this out. if i just stare at the fp gage i can see just the slightest ocsillation, about the width of the point of the needle, but i have to really look at the gage to notice it.

If the above two conditions were true, then nothing makes sense . Condition #1 clearly indicates the stock return fuel line being the problem but #2 immediately disproves #1. I don't know, I have to think about this one. Good job on trying to get to the bottom of this and continues to update us with such detail, most would have given up long ago like daren_p. Please correct me if I misuderstood you in 1 & 2.

i can not grasp the concept of what is going on and am about ready to give up myself. the only thing i can figure is maybe an error when the factory/whoever built the bulkhead/flange for the gas tank for my car. i can get the ltft lo and mid to within tolerance according to the dsmlink manual though and am about ready to live with it because i think the worst is maybe a loss of a couple mpg which would not be worth the effort of re-working the flange. just trying to get opinions on if i am correct or not. i still need to finish breaking in the clutch before wot tuning but think it should go ok "as is".

jim

 

[DSM90AWD]

Did you happen to plug the vapor line comming off the tank (would normally be connected to your purge canister). Gas being voltile as it is, (+) pressure can quickly build inside the tank. If this line was plugged, you could very well be creating a restriction on the return line.

Another thing you may want to look at is the tank inlet itself. It's possible that OEM rubber return rotted some chunks that are plugging the line and/or maybe some residual teflon tape form the FPR install. May want to take a small plastic straw (from a carb cleaner can) and gently probe/clean that tank fitting

 

[FORMONTOYA]

Did you happen to plug the vapor line comming off the tank (would normally be connected to your purge canister).

This was it!!

I guess you made this suggestion after seeing the car was up on stands for 11 months and had an idea I would have some "lull" time and do some cleaning up on the underside, suspension, and engine bay of the car, which I did. Evidently while putting back on some of the parts I managed to kink the line, not all the way, but enough to give me headaches.

I finally had a chance to get back on the car today and found my mistake. I think I was as happy seeing the fuel pressure drop 10psi as the day I first started the car after 11 months. The only downside was that my low fuel trim was a little wack, but nothing that a little tweak to the deadtime couldn't solve. 44psi base with hose off, 34psi with hose on at 20"vac.

Now I can't wait to get this clutch broken-in so I can do some WOT tuning.

I really appreciate everyones help in solving this problem,


Jim

 

[oldman]

Very nice indeed, this is what happens when you don't give up. There is always a cause and solution to any problem and you just have to find it, I'm extremely pleased and impressed at the result as well as your resolve.

 

[DSM90AWD]

I guess you made this suggestion after seeing the car was up on stands for 11 months and had an idea I would have some "lull" time and do some cleaning up on the underside, suspension, and engine bay of the car, which I did

Actually I did plug mine deliberately when doing the "Taboo" vaccume line elimination. Came to the conclusion was not such a good idea to plug that line when my gas cap kept rocketing off with a whooosh everytime I went to fill the car up

Glad you got it all sorted out