66 impala

iTrader: (5)

Just as the title says it floods out and wont start everytime i get gas. In order to get it to start i have to pull the fuel pump relay, crank it, and plug it in before it dies. Even flooring the rtek 2.1 i have to cut the pump off dont work. Also when i pull the pump relay out the car turns over alot quicker, why is this? Things about the car to diagnose this..........

It ONLY does it after i get gas
Car has zero emissions
fuel mods:
walbro 255
750/1200 injectors

Also i premix the car 1oz per gallon, i put the premix in first with a funnel, spray some fuel in the funnel to wash all the premix in then finish fueling. Could the premix not mixing right cause this?

Brodie121

iTrader: (8)

Seems like a dumb question but do you let the engine get to full operating temperature before starting it? Do you mean it won't wont fire instead of wont crank? cause not cranking means it isn't even turning over.

66 impala

iTrader: (5)

sorry i worded it wrong yes it turns over and tries to start but the only way to get it to start is to unplug the fuel pump relay under the steering column. Not sure what you mean though by gettin the full operating temp before starting though.

RX_Spec

iTrader: (2)

Ive had this same problem on both my 7 and my cobalt...both times it was the fuel pump going bad.

66 impala

iTrader: (5)

u think with me opening the gas cap its letting out the vacuum built up in the tank?

Brodie121

iTrader: (8)

there shouldn't be a vacuum in the tank, pressure, maybe

RX_Spec

iTrader: (2)

that's exactly it...in my Cobalt it was called a purge solenoid connected to my fuel pump...and every time i released the pressure i had to tap on the gas to "build" pressure back.

Brodie121

iTrader: (8)

Sound to me more like leaky injectors

66 impala

iTrader: (5)

they are brand new rc injectors and the fuel pump is a bran new walbro. The injectors have 500 miles and the pump has 1300. Also it doesnt do it any other time unless i stop and get gas. I could turn the car off for as long as it takes to get gas and it would start back up fine.

66 impala

iTrader: (5)

if it was a bad pump i dont see why if i unplugged the relay it would crank just fine

Brodie121

iTrader: (8)

That's really, really strange.

RX_Spec

iTrader: (2)

there ya go....bad relay maybe?

Brodie121

iTrader: (8)

I think he means he pulls the pump fuse under the hood, correct me if im wrong.

66 impala

iTrader: (5)

no the relay under the steering column

Brodie121

iTrader: (8)

ok, just try tapping the relay with something next time this happens, if its the relay going this might get it to go.

66 impala

iTrader: (5)

ill try it

66 impala

iTrader: (5)

any other opinions?

rotorsport72

this is from Mazda Trix not me but thought it would help explain your promblem. The main symptom is flooding after the car has been sitting for a short time. It can manifest itself after running for as little as a minute or two! Basically, if you try to re-start the car anywhere from a few minutes, to an hour, it just will NOT start. The "no-start" is usually OK after sitting for a few hours or over night.
The injection systems hold residual fuel pressure for many hours after the engine is shut off, and if an injector is leaking, it will simply drip fuel in the engine until the pressure has stopped. This part we have assembled should be considered a temporary fix, or a diagnostic tool only, because it is not going to fix the root problem. However, it can get the car back on the road for a lot fewer $$ than new injectors. Plus - it is hard to find out which injector(s) are the problem - you have four! they sell this kit its ok but you are better of sending them to get clean. good luck

Dusty2Rusty

I Have the same problem as you, here's how I fixed it, Install a toggle switch that cuts off the fuel, then when you get the problem cut the fuel, push down on the Accelerator and turn the key, when you hear the engine start to ignite turn the fuel back on and keep it at around 3k rpm for a few seconds. Works for me every time.

Brodie121

iTrader: (8)

What these people are saying is not fixing the root of the problem, just covering it up. But from what i can tell your injectors shouldn't be leaking. Try just removing the gas cap as if you where going to get gas and see if it floods.

66 impala

iTrader: (5)

^ thats what i was going to do.....i was thinkin of the toggle switch inline with the relay but i shouldnt have to cut it off

66 impala

iTrader: (5)

well i removed the gas cap and opened the flap inside the filler neck for about 30 seconds and it cranked just fine. Just to make sure i did it twice back to back and both times were the same. Im stumped.

Ocho Siete

thaks for starting this thread cause i have the same problem and honestly i believe my primaries are leaking and to start it i pull out the (enj ingn 30 amp relay) undr the hood crank it for bout 10 sec then plug it back in but i just want to fix it that **** is embarissing and annoying


let you know when i fix it

Brodie121

iTrader: (8)

Almost sounds like leaking injectors again, even though theyre new. Whats your compression like? When you tried taking the gas cap off had you run the car to operating temperature beforehand?

66 impala

iTrader: (5)

compression is 95 psi on front and rear rotor and yes the car was at full operating temps