fuel pump relay question with PICS!!!

[speedfreek88]

alright... for those of you that dont know ive had some fuel pressure problems lately with my fuel psi pegging my 100 psi gauge. my a/f at idle has been high 11's low 12's. its not my gauge or sending unit so im thinking it might be my relay.

does anyone have a pic of where its located and is it just unplugging one and plugging in a new one? where can i pick up a new relay and for how much?


last question, ive wondered what this is since i bought my truck... it looks alot like a relay, any help?

 

[throttle jockey]

Yes, that is a relay laying loose under the S/C, I wonder how/why that got there :shrug:. Give me a minute and I'll find you pics of the fuel pump relay and the high/low relay. The owner's manual list them as well.

 

[throttle jockey]

Since the damn "search" feature is currently AWOL this is taking much longer for me to find than it should to.

Here's a pic of a the location for the high/low relay (where the jumper wire is located). The fuel pump relay is in the fuse/relay box next to the two relays pictured above.

 

[throttle jockey]

* Disregard the long pink wire in the pics below *

Here the location of the fuel pump relay (the relay with the "X" on it):

And for future reference here's a pic of how to jumper the fuel pump relay:

 

[speedfreek88]

actually that relay that i found is bolted down right there (you can barely see the top of the bolt in pic 4)... can i use that one?

which relay should i replace first to try to solve my problem?

 

[RIDE THE]

I'm really curious as to why someone would mount a relay to the alternator bracket. It would get heat soaked by being mounted there.

A relay is just an on or off component. It will not cause your fuel pressure to spike over 100psi.

I don't think even the Walbro's can hit 100psi with bypassing the resistor. Do you have a link to another thread that goes over your entire issue?

 

[N20JUNKY]

are you the original owner? someone might have had a nitrous kit on the truck before you and never told you

 

[speedfreek88]

since the search function doesnt work ill sum up...

a few days after i got tuned for my kb2.3 and all other mods i put on in the past 3 months i get in my truck to go up town to eat and it pegs my gauge at 100 psi... before that it had been reading a constant 70 psi with pumps at full voltage with perfect a/f. i hadnt been gettin on it due to sub freezing weather and i just limped it back home and took out my beater. the a/f is a little on the rich side now high 11's-low 12's at idle and the gauge stays at 100 psi. its not the fuel psi gauge or sender (tested fine).

here's a link to another forum... High Fuel Pressure? - Lightning Forum | LightningRodder.com

the original owner threw a rod with a #4 lower cuz he is retarded... new motor as of ~10000 miles ago. before i bought it

 

[speedfreek88]

anyone? id like to get my truck fixed today... i hate just watching it sit there

 

[speedfreek88]

took it out for a lil spin today so i could vid whats goin on... the a/f was a lil low at first (hasnt ran in a few days) but once it got warmed up it was fine. the fuel psi was still pegged at 100 but it would come down the more throttle i gave it.. all the way down to about 58-60psi at full throttle. none of my vids turned out due to the tinted glass on the front of my gauges but i did catch this when i got home... what you think?

 

[RIDE THE]

There is something very strange about how it is jumping around.

I know that you said that the gauge and sending unit are good, but the first thing I would do is to put a mechanical fuel pressure gauge on the fuel rail to make sure the system does actually have has an issue. The way that it is jumping up and down 15psi would lead me to believe it's a sending unit problem.

 

[speedfreek88]

the sender itself is fine and i checked all my wiring... could it be a glitch in the gauge itself? ill try to find someone with a mech gauge...

 

[RIDE THE]

You can rent one/borrow one from most auto parts stores like Advanced or Autozone. If you still have your factory schrader valve in the line you can check it in the parking lot and take it right back in.

All you need to look for is the same freakishly high fuel pressure.

 

[compsystems]

I agree. Something is wrong with the sender or gauge. If your fuel pressure did vary that fast and was that high you would see a fluctuation on both your Afr gauge and vacuum gauge as the injectors would put out a varying amount of fuel.

Double check all your ground wires. Something is dirty or loose.

 

[speedfreek88]

thanks to everyone for their input... its been 3 months and 2 weeks since ive got to "drive" my truck and im ready to tear up the streets!

 

[Zak Attack]

If it makes you feel any better I LOVE THOSE GUAGES.

 

[speedfreek88]

haha thanks... theyre pretty cheap because the company doesnt use any promoting or advertising other than word of mouth and their customer service is top notch!

i borrowed a fuel pressure tester from autozone and it read 65 psi.... is this normal for walbro 255s at full voltage?

 

[speedfreek88]

anyone? 65 psi normal?

 

[throttle jockey]

I agree with Eric and compsystems... after watching the video you posted it appears as though your problem is either with the sending unit or the gauge itself.

65 PSI for the Walbros at full cycle should be about right.