KingsHustleLA

So I Put In A Walbro 255LPH Fuel Pump In My '90 Iroc-Z A few Days Ago & Last Night My Fuel Pump Stayed On & I Heard Like A Gurgling Noise By My Intake Manifold. It Keep Doing That Untill My Battery Finally Dies, It Didnt Do That At First But Last Night It Started & Has Been Doing That Ever Since, Now Can That Be Because Of Me Wiring It Wrong, Or Does It Have To Do With The Fuel Pump Relay Or Anything Else It Could be Thats Causing This? Thanks.

84redta

iTrader: (34)

Oil pressure sending unit down by the oil filter is bad.

Don't think there is much that could be ruined in there. The kit you got came with the correct pigtail for the pump right?

drknow90rs_ss@y

iTrader: (3)

I always thought that the oil pressure sending unit going bad would result in the fuel pump not turning on... Now a stuck relay will cause it to stay on. My RS uses a walboro 255 and I had this happen after a few months. The current draw is more and as such, the contacts in the relay became arc'd and welded together. Havent had this problem in the 4 years since replacing the relay.

Good luck!

84redta

iTrader: (34)

That is always a possibility, but 9 times outta 10 situation is the oil pressure sending unit, but then again it's if it's staying on out of no where, of course there is a possiblity that something is ary when the tank was dropped.

As far as the OPSU, it serves as a double for if/when the fuel pump relay goes bad. After like 10 PSI the OPSU will send 12v to the fuel pump, thats why some cars have to turn over like 5 or 6 times before it'll start, because the computer isn't priming the relay (or the relay is bad). You can try relay as it's a hell of a lot easier to check/try.

vetteoz

iTrader: (13)

OP switch has contacts as well ; if they are locked together then power will flow to pump full time
regardless of key position

camaronewbie

Huge misconception with the oil pressure switch - many think it's some kind of safety feature that disables the pump in the event of no oil pressure (like a bad wreck), but it's not - it's designed to run the pump in the event of a ECM/relay failure so you can limp home.

Hasn't been any fuel cut-off safety feature added to vehicles until just recently, and they are tied into the air bag system not oil pressure.

84redta

iTrader: (34)

It would be sweet if there was such a sensor in the GM lineup though, I'd rewire half of my LT1 harness to enjoy that piece of mind.

vetteoz

iTrader: (13)

Would be easy to do but you would have to remove the ECM control of the pump relay ( which is in parallel with switch ) so OP switch was sole controller of fuel pump
Then you could change the switch to say a 10psi one so switch would work as dead engine safety pump cutoff and low oil pressure cutoff

camaronewbie

Or rig a relay into the fuel pump wires close to the tank (after the OPSU and ECM/relay) that is wired to cut power to the fuel pump when 'energized' by power from the airbag circuit. Air bag deployed = relay energized = fuel pump disabled.

KingsHustleLA

Thanks Everyone For Helping Me Out 1st Of All I really Appreciate It, As A Matter Of Fact My Oil Pressure Sending Unit Is Bad My Car Has Been Leaking Like A *********er For The Past Few Weeks. So If Thats Bad That Would Make My Fuel Pump Stay On After I Turn The Car Off? My Old One Was In My Car Before When The Oil Pressure Sending Unit First Went Out And It Never Did That But Now I have The Walbro 255LPH So With That Pump The Oil Pressure Sending Unit Can Make The Fuel Pump Act Like That???

Chevy86 IROC-Z

iTrader: (17)

Have you tested the Fuel Pump Relay? It may be arching itself to the closed position. Food for thought.

KingsHustleLA

This Might Sound Dumb, But I Dont Know Where Its Located Or What It Looks Like So I havent Been Able To Get It Checked, I Need To See Like A Physical Picture Of What It Is.

Chevy86 IROC-Z

iTrader: (17)

Its to the right of the brake booster. There are 3 relays there. You'll have to look for the color codes for the wirng to be able to identify which relay is the FP Relay.

KingsHustleLA

Oh Okayyy So It Was One Of Them! Theres 2 Right There Against The Firewall To The Far Right Corner, They're Black And Have Wired Plugged Into The Bottom Of Them Would One Of Those Be It?

Chevy86 IROC-Z

iTrader: (17)

Well in my 86 IROC, I have 3 relays. So you will have to look for a wiring diagram to verify. Wait a minute, yes. One of them should be your fuel pump relay. My 3 relays are FP, MAF Burn-off, and MAF Power. But you dont have a MAF Sensor, so that eleminates 2 for your Camaro.

SiCkRs

iTrader: (6)

hey Chris the fuel pump one is the one thats all the way to passenger side or thats how it was on mine

Chevy86 IROC-Z

iTrader: (17)

Ohh. And this is not a dumb question!!!! A dumb question would be something like, "Should I take my Mustang to Thirdgen Fest this year?"

KingsHustleLA

Chevy86 IROC-Z - Yeah That Would Be A Stupid Question LoL Ohhh Ok I See, My Car Doesnt Have A Mass Air-flow Sensor So That's Probably The One Im Missing


Rodolfo - Alright For Sure So It Should Be The Left One Then, Ill Check It Out

SiCkRs

iTrader: (6)

or if u dnt find it ill send u pic tommorow since im at san diego right now

Chevy86 IROC-Z

iTrader: (17)

BIG SD!!! I live just east of you in the next county (Imperial Valley).

Chevy86 IROC-Z

iTrader: (17)

You otta drive to Coronado Bridge, pull over and take a picture of your Camaro with National City and SD in the background.

SiCkRs

iTrader: (6)

Once i paint my ill pm you to tell me exactly were it is to get some pics of with fresh paint lol

Chevy86 IROC-Z

iTrader: (17)

. Right on man! Alright, Lets get .

SiCkRs

iTrader: (6)

srry chris jacking your thread

84redta

iTrader: (34)

if you unplug the relay and it stops running, it was the relay. May be obvious or it may not, just throwing it out there. The computer sends 12V to the relay to turn the pump on, so if you unplug the relay and it stays running, from my memory, the oil pressure sending unit is the only one capable of giving the fuel pump 12V without actually having to flip any switches or turn any keys. And I do not believe that all instances of a bad oil pressure sensor can leave the pump running. Right now, on my firebirds original motor and the new LT1 i just put in, both oil pressure sending units are bad, but both just equally gave really crappy(inaccurate) oil pressure readings to my gauge inside.

alloy

iTrader: (16)

I'm having the same problem in my second camaro, an 89 TPI car.

I pull the relay and the fuel pump stays on, pull the connector off the oil pressure sensor and the pump goes off. Plug the relay back in and the car runs and shuts off like it's supposed to, but gives me a code 54 low fuel pump voltage.

I've replaced the sender 4 times now. First one when I bought the car in Dec of 09. Fuel pump was out and I got the car very cheap. The oil pressure gauge also wasn't working and replacing the sensor cured that.

A few weeks ago we almost lost the engine due to the oil pressure sensor going bad and we lost 4 quarts of oil in 20 miles. Got lucky and caught that before it fried the engine.

I replaced that oil sensor and it worked for about a week, then the fuel pump stayed on after shutting the car off. I replaced the sensor again and it lasted about 2 days and the fuel pump kept running. Like I said remove the relay now and the pump keeps running, remove the connector off the sensor and the pump goes off.

Seems odd to me I'm going through sensors so quickly. I know these have a habit of going bad, but in 2 days???

Gumby

That for me was at the bulk head connector in the back of the car where the wires run through the body for the FP, there is a connector on the outside for the FP wires to unplug. [pull up carpet in the back just behind the rear seat]

I ended up wiring around it / wired it direct by passing that bulk head n pig tail.

alloy

iTrader: (16)

I guess I should have made myself clearer. I get a code 54 when the car is running with only the relay powering the fuel pump and the oil pressure sending unit disconnected.

This proves to me it is the sending unit keeping my pump on.

In looking at another thread where it was suggested a relay be used to bypass the sending unit when the key is on. But doing this won't let the switch do it's job of turning the pump on when there is cranking oil pressure.

Someone suggested maybe my pump is drawing too much current and welding the contacts together in the sender. The pump is only about 15 months old and I really can't see it going bad in that time. I'm considering using the sender to turn a relay on that powers the fuel pump when the cranking pressure comes up. This would take the current load off the sender and still keep the cranking oil pressure safety feature intact.

I'd rather find and cure the problem, but I just can't find a reason for losing so many sensors in such a short time.