Fuel prob

[high c]

hey guys, so my newest problem...i went out the other day to try and tune my car a little bit better. I hooked up my WB 02 sensor, plugged it into my laptop and started the car. During start up i began to collect data, and it was at about 14.7 for a bit, then began slowly rising to eventually getting to 21, which is the leanest that it can read. I alreayd reburnt the chip, and still same prob. So it isnt the ecu, i replaced the fuel filter today thinking maybe it was clogged, and it wasnt that either. I also have ruled out a faulty sensor by reading all the plugs, and they confirm that it is running lean, and also hooked it up to another one of my cars and it reads fine....Only real thing i can think of that we havent checked yet (tomarrow) is the sock on the fuel pump, maybe it is clogged or my pump is bad...which is gonna be mad *** bc i just replaced it like <1 year ago with a 255lph joint...

so anything else that you guys can think it is?

[xfactortype1]

clean your injectors lately? just and idea

[F22Turbo702]

I know you say you replaced the pump like a year ago, but that's what I would lean towards. Do you have a fuel pressure guage? If so, I'd check the fuel pressure. Could be injectors, but....check fuel pressure.

-Kyle

[high c]

fuel psi is really high 86 psi at the rail and i took out the injectors and cleaned them today by blowing compressed air/carb cleaner at 60 psi back ward through them, i also replaced the fuel filter and it hasent halped at all...

I also checked out what was on the chip, and it is the same map that i was running before without any problems...i even unchecked the 'closed loop disabled' box just for shits to see if it would do anything, and alass nothing...

any ideas guys?

[xfactortype1]

maybe your fuel pressure regulator, or the vaccum line to it is undone? or even the return line is pinched (hit a bump?) causing backpressure? just throwing ideas

goodluck x

[bjaccord]

maybe your fuel pressure regulator, or the vaccum line to it is undone? or even the return line is pinched (hit a bump?) causing backpressure? just throwing ideas

goodluck x

This would make it run rich, not lean, as his is.

Why do you have so much pressure in the rail? Should be like 42 with 0 vac/boost, unless you have an adj. regulator that you went crazy with. L8r

[xfactortype1]

here a link for aem fuel system info in regards to fuel pressure and regulators and crap. bajaccord it also mentions the pulse dampener which you asked about in another thread. i just thought you might find it useful or may even learn something.

Many vehicle manufacturers use a pulse dampener to reduce the pulsations in the fuel rail caused by the opening and closing of the injectors (a dampener also reduces the noise of the injectors). In applications where a new fuel system must be installed, a fuel pressure dampener is integral to ensuring consistent fuel flow to the injectors. AEM fuel rails have a provision for a pulse dampener. The dampener assembly part numbers are:


http://www.aempower.com/faq.asp?fid=17&sid=&tid=2

[high c]

im getting a new fpr tomarrow, im thinking that what might be happening, is i have so much fp, and it is holding the injector shut/not letting it open properly...i have checked the return line, doesnt ahve any restriction, cleaned injectors, changed maps on ecu, blah blah blah.

i dunno what else it really can be...im kinda getting to the last straw, so there might be a completely forged and arped out engine for sale up here soon

[high c]

ok so update...i replaced the fpr, and still i have high fuel pressure...also just checked the resistance of the resistor box to the injectors and that is all in specs from the haynes manual...i also ran the car on the STOCK fuel pump, and although i did have less pressure, it still started about 14.7 and then slowly rose until it was back to 21, which is the leanest it can be

I also got under the car and checked for any dents or antyhing that could be restricting the flow back to the pump, and nothing. To confirm that the return was still good and functional, i disconnected the return line just after the FPR and pointed the hose into a bucket. I ran the car for about 2 mins with it pumping fuel into the bucket, and still high fp and also lean readings...

anyone have any ideas?

justin isnt a happy camper

[bjaccord]

What kind of vaccuum are you pulling at idle? It really shouldn't matter but just curious. 0 vac will obviously have more fuel pressure than say 20 (A good place to aim for at idle). By pulling the vac line off of the fpr at idle does the pressure raise as it should?

L8r

[high c]

i am pullin between 20-22 at idle, i will have to try taking the vac line off and seeing if the pressure rises... thanks for helping me out bud i appreciate it~
justin

[bjaccord]

Well vaccum seems good, but fuel pressure shouldn't be much higher than 30 (More like 25) with that kind of vaccum, and 40-45 at 0 vaccum (Or pulling the line off of it, and making sure to cap it so there isn't a huge vac. leak). Let me know what happens when you pull the line. L8r

[high c]

isnt that just testing the regulator? I replaced it with a stock reg, and the fuel pressure is suppose to be 42.5 i believe...the gauge now reads a constant 75, but the gauge probably isnt the most accurate gauge in the world, so i am planning on buying another gauge for it...

[high c]

ok so here we go again, so the other day when i hit my kill switch to give the ecu power (and turn on the fuel pump) i would just hear an electrical squeek sound. I replaced the Main relay under the dash (which yes was a bitch) and then the kill switch worked fine and all, i would hit it and give the ecu power and bam, pump kicks on, just like it was suppose to. So that main relay prob had about 5 mins total run time on it between maybe last wends and this evening. So i go out tonight and try and start the fucker to atleast get it outta my garage and just like that, squeeking again and no pump activation or priming. SSOOOO i am leaning towards my main relay being junk again...now i know that main relays can just go bad over time, but if lightening didnt stirke twice, what could be killing my main relays? And if it were to go progressively to shit while the car is running, could this account for my running right when i start the car, and it getting progressively leaner? Maybe the relay isnt sending correct voltage/amperage tot he pump, thus giving me pressure in the line but not volume? Any help is greatly apprecaited guys, im getting to my last straw with this car, just really wanna get it running right so i can enjoy my $$$ engine...

justin

[WiKKeDV16]

thats a possibility.. if u want to eliminate that.. just run a powerline directly to the pump.. a 12v source to test off of.. basiclly bypassing the main relay,


also.. out of curiosity have u tried a different map..?? something totally different.. if ur main relay has been acting stupid what are the chances of it glitching the map? making it faulty.. ? (Bad burn scenario).. regardless just use a totally fresh map and see if that does anything..