fuel pump hardwire/rewire

[s13silady]

anyone know if its possible? or anyone done it before here in san jose willing to help me out? basically i want the fuel pump to run off its own power source but still connect to my ECU for the stock prime effect...

i did a search and came up with the 30amp relay conversion... just wondering if this owuld get rid of my problem with the shorting wires causing my car not to start sometimes.

thanks

-ryan..

[Dousan_PG]

yeah possible
find the power line on the harness
easy to do. super easy
mega easy

break out the FSM

[msaskin]

Relay in trunk near fuel pump.

10-12ga. power wire direct from battery to input on relay.
Stock fuel pump power wire to + trigger on relay
Ground - (neg.) trigger and neg pole of relay to chassis

Stock fuel pump power will flip the relay, which in turn will power the fuel pump directly from the battery.

Worst case scenario and you blow the relay, just reconnect the stock wires and call it a day.

~matt

[s13silady]

ok quick recap... i hardwired my fuel pump completely with its own power source (battery), independant ground, and new relay. and i spliced into the ignition wire of my turbo timer...fuel pump gets power no problem at all.. the cars still not starting... so my other buddy with an SR stops by and lets me swap ignitor chips to see if this was the cause... same thing no go...
it just cranks and cranks and cranks.. doesnt turn over all the way...
a shop told me that the power leak is coming from ignition relay... i have yet to check that will do first thing in the morning...(oh and also my coil packs..)
can someone also tell me where the ignition relay is located? (seems dumb but im having a small problem trying to find it...)

SR20DET redtop...in a 90FB...

if anyone can throw out suggestions that would help me trouble shoot id be very greatful...

CLIFFNOTES: my car cranks..doesnt turn over.. rewired fuel pump.. works good now...checked for spark..none...checked ignitor chip, and not the problem...

[s13silady]

anyone????

[proj240sx]

did you pull your plugs out and check to see if they are even sparking?

edit: whoops sorry

[s13silady]

did you pull your plugs out and check to see if they are even sparking?


"...checked for spark.."

yes i did...

[kickertu]

might be a wiring issue..

i know this is dumb.. but is your ecu screwed into the harness?

[driftstyre]

The IGN Relay is in the fuse box in front of the passenger fender. The fuel pump (IGN Pump) relay is right next to that. I recently had a similar problem and ended up re-timing the crank angle sensor and the engine ran but would misfire under load conditions. The more I turned the CAS clockwise the better it ran. If you're getting spark and fuel it most likely is your CAS as its firing at the completly wrong times.

[s13silady]

i thought it was my cas too.. but if a cas were to go out it would have more of a chance to go out mechanically and not electrically... the problem i have is an intermittant (sp?) problem.. so it has to be electrical... im going to have my wiring checked out first thing monday... ill keep posted...

oh and also i see a lot of people lately have been having fuel pump issues so im going to do a write up for the fuel pump relay mod with pics as soon as i get this problem squared...

[AN89HATCH]

i thought it was my cas too.. but if a cas were to go out it would have more of a chance to go out mechanically and not electrically... the problem i have is an intermittant (sp?) problem.. so it has to be electrical... im going to have my wiring checked out first thing monday... ill keep posted...

oh and also i see a lot of people lately have been having fuel pump issues so im going to do a write up for the fuel pump relay mod with pics as soon as i get this problem squared...

check your distributor cap and rotor

[kazuo]

check your distributor cap and rotor

He has a RWD SR20DET.

I was glossing over the post and I just read it... seems you did it all wrong dude. That's why its not working. You're looking for the solution in all of the wrong places.

GO search FA under username "Enthalpy," he posted a very simple schematic on how to do it.

Good luck

[s13silady]

haha.. thats what i followed... did exactly the same.. it works.. but its another problem thats not starting my car...im just saying ill do a write/up with pics because the enthalpy way doesnt have pics.. :)

little update: i switched the EGI and the EGI pump relays under the hood and the car started... but i waiting to see when its going to go out again...when relays go out its usually intermittant... so im going to see if this was the problem...

yah i checked my cap and rotor and replaced my spark plug wires also.. still no go... and i made sure my blinker fluid is good... jk. :angel:

[s13silady]

ok... i thought i solved the problem... but i didnt... i thought it was just the fuel pump relay and ignition relay in the box under the hood... its not...

so im beginning to think it is either my main relay, or my ignition lockswitch...

those would be the best bets on why i have this problem...do any of you guys have any idea? or at least know if im on the right track..? i dont want to spend $150 for a new main relay and have it not be the problem...
if it does turn out to be my main relay, it would be located somewhere under my dash i assume (correct me if im wrong)

if any of you are in the san jose area and willing to help me out with this problem to check i would greatly appreciate it and or pay.. its been been a month now and this problem is a mystery still...

[kazuo]

You need a multimeter, a FSM and a lot of patience.

I say you bypass your stock wiring, run your own power/ground wires to the pump, and wire a relay in the back. Make sure the power wire has a fuse inline.

That way, you cut out the bullshit and get the problem solved ASAP.

Total cost = less than $50 and itll take like an hour or two

I think Enthalpy also posted how to do it on FA? It's not too hard...

[s13silady]

ive done that...but i have arised to the new problem of not getting any spark... a shop told me that the problem was sourced to the ignition relay... but im thinking that its the main relay... but i dont know how to get to it..

[kazuo]

ive done that...but i have arised to the new problem of not getting any spark... a shop told me that the problem was sourced to the ignition relay... but im thinking that its the main relay... but i dont know how to get to it..

All the relays are right there in the engine bay in the fuse box. Big ass green ones IIRC.

I dunno what your problem is... if you bypassed it it should work fine... if you're not getting spark, you have bigger fish to fry.

Good luck

[s13silady]

well i was told the MAIN RELAY is under the dash somewhere... i just need this clarified..