like the title stated i installed a external fpr . i spliced into the soft line on the return side . i turned on the power an relized i need to tighten the fitting it was leaking still . i tightened that an then nothing . pump is not priming , no code . i did notice the the regulater was adjusted for as much pressure as possible . it's a 0-140 psi regulater . my question is if it stopped all fuel from returning to the tank could it have blown a fuse or messed up the relay or even burnt up the pump ?

 

ok fuse by the battery is good , replaced the fuel pump relay .... any ideas ?

 

ok found the problem , the mechanic lol . be sure to plum the reg . into the return line not the supply line . lol
ooooppps .lol

 

at least you found what was wrong.

 

yea it works great now ,only able to get 15 psi of fuel pressure . .i knew i was gonna need a new pump so thats no big deal . it only had about 8-9 psi when i first hooked up the fpr . so it helped alot .i haven't drove it yet cause i gotta put the seat back in but it sounds really good . now that i wasted all weekend messing with this i guess i'll put my aluminum intake on next weekend .

lesson learned > don't get tore up before you start working on the car .lol

 

In your first post it said you put it on the return side. guess got the 2 mixed up? glad you got it installed. can i see your installation pics? im doing this very soon myself. what regulator did you run?

 

i'll take pics monday , i order a cheap one off ebay . 30 bucks 0-140 psi with the 1-1 boost reference . yea i thought i had it on the right line but i was wrong . supply line is 3/8 return is 5/16 for future reference . to manny budlights an sum good smoke had me alll ****ed up .lol


if i would of had the extra cash i would of used the aeromotive fpr , but this is a very low budget build .

 

heres the pics :

 

she's running rich i need to do a few ebl learns but damn she likes the extra fuel on the top end . now i can put the pro comp aluminum intake ( 1500-6500 rpm ) manifold on .

 

hey that looks good.

hey undercover im going to move mine IF I KEEP IT. I am wanting to cut the steel lines under the firewall and put fittings on it. if I keep the reg I was going to move it over where the relays are on the firewall. I am going to move the relays also. but I may go back to the adjustable regulator on the tbi with the different springs if not adjustable. and still do the line cut where the lines never come up to the front.

 

Yeah I thought about doing mine like that a "not as clean" install. im kind of torn on it. I am a cheap ***. If that regulator works why not ya know. And installing it like that. We are only dealing with 10-25 psi on most of our cars using hose clamps and barb fittings would be sufficient it seems.

Thanks for the pictures btw. I know it takes time and it is appreciated greatly.

 

yea no problem on the pics . i'm gonna chane the line to braided some time in the near future . i'm having a few issuse but none are regulater related . i'm getting somewhere between 12 - 14 psi max . my a/f are spot on 12.4 just what there set for but my dc% on injecters are still high 90's to low 100's . i believe i need more fuel pressure . i'm gonna run this past rbob an get his opinion . i know i need more in order to put the aluminum manifold on an difinetly need more before the turbo install . this is why i do one mod at a time so i can see the results an don't have to guess at what the problem is if it goes bad . i'm thinking about getting a tpi fuel pump it should push as much pressure as i'm gonna need .any more than 35 psi an i'm gonna up grade the injecters . i need to start a build thread instead of all these small threads i guess .lol

 

your still running tbi pump? mine would provide 15 psi of fuel but not enough volume at all. i switched to walbro 255lph and the stock return system would not handle it. so then i went to ac delco ep241 tpi pump and have had no complaints.

im having spark knock at 3800 rpms + so i am switching to 454 tbi unit with 454 injectors and an vafpr to try and cure that.

right now im running holley 2bbl tbi with 85pph injectors at 21 psi. need more fuel than those can provide.

 

 

that looks good one92rs

 

Shoot for 85% max. I find highest DC% is in 1st or 2nd gear pull of 4 manual trans.

 

i know ronny i'm going to order a tpi fuel pump in the near future . by changing my fuel pressure i have come down from a very lean state 17.0 a/f at wot an about 117 % dc volts to 12.4 a/f an now 94-100 % dc volts . i have a auto 700r4 an the wot was on 2nd gear . any advice tho is much appriciated .

 

A/F WOT or part throttle A/F may not change by adding fuel pressure. Your injectors are just over worked beyond capacity. 100%/85%= 1.18. May not be the proper increase in fuel pressure but I would bump FP by 20%, maybe 25%. That should bring down the DC unless the pump is inadequate.

 

thanks ronny , i have to get a new fuel pump . this will only go to 14 psi . i'm gonna buy a tpi fuel pump

 

so more fuel pressure decreases duty cycle?

 

yes , i believe thats what he's saying .
my pe is set for 12.4 a/f what if i adjust it for 13.0 my duty cycle should drop plus leaner is meaner right ? of course i still need the pump becouse of the turbo in a month or two . but for right now will that help ? i only have high duty cycle at wot .

 

Yes DC% decreases with higher FP.

 

how about if i change my wot a/f topend to 13.0 instead of 12.4 shouldn't that lower the demand on the injecters ?

 

I believe it would. However that is not the way to tune. PE I believe is leaner initially(gear 1 of 4) then it enrichens as load increases due to higher MPH(higher drag). Assuming the def file supports that concept. 12.8 transitioning to 12.4 is where you want to be.

 

i realize the duty cycle is maxed will this hurt my injecters ? ( the a/f is 12.4 there ) i do a wot at least once everytime i drive the car which is about 1-2 times a week . at least until i get the new fuel pump, or should i try tuning to the 12.8 - 12.4 until then ?

 

I recall static means they are wide open with no cycling of pindle. you lose all A/F control when over 90% or so. In fact I read it can actually go RICH A/F.