well after sitting for a couple months i am caught up on other stuff where i can get back on my fc.

im really starting to miss it


maybe i was confused on my afr's hailers2. thats irrelevant until i get my car to run again im afraid.

so here is where im at... i replaced my fuel pump with a brand new walbro. and i rebuilt my aem pressure regulator with a new diaphram.

car still wont hold fuel pressure. i can start it and it will barely run. like its running on one rotor.

the fuel pressure gauge is hopping all over the place while its running. shut it off and it quickly bleeds off. its pressure is down to 20lbs by the time i can quickly get out of the car and look under the hood at the gauge.

what else holds the pressure?
is it time to pull my injectors and have them checked out? keep in mind i only have a few thousand miles on them since they were rebuilt by RC.

frustrated:/

 

Statement #2 in post #25 might have some value to you.

 

in addition to the fuel pump being new it has also been rewired without the resistor pack.

 

The voltage from the Circuit Opening Relay powers the fuel relay that you deleted.

 

I rewired the pump by following arghx's diagram on his thread. Am I missing something?

 

The statement below makes no mention of the fuel pump being wired differently other than the fuel relay being deleted from the equation.

"in addition to the fuel pump being new it has also been rewired without the resistor pack."

 

The relay is not deleted. The resistor pack is.

 

You stated the pump was rewired w/o the resistor pack. First off, the resistor pack is an item that is for injectors of low impedance as it is not related to the fuel pump. And resistor packs are not found on an 88 RX7. Now the fuel pump relay and resistor, which is located underneath the air box, is associated w/the fuel pump. So if you bypassed this feature then you removed one of the two relays associated w/the fuel pump.

 

sorry if im not making sense to you. or if i sound like a noob. this is a learning process for me and im doing the best i can. the city i live in is only 25 thousand people and no one knows **** about rotaries here. the closest thing i have to a tech is this forum and whatever else i can find on the net.


this is what i did
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/pics-my-overkill-fuel-pump-rewire-732904/

problem was the same before the rewire. nothing changed. except im getting full voltage at the fuel pump now.

how would this make it not hold pressure?

 

I would still look at the info provided in statement #2 in post #25.

You can also measure the fuel pressure after the fuel filter to narrow down your problem.

 

what are you referring to as statement #2?

 

Check valve in the tank, but if you measure the fuel pressure coming out of the fuel filter it will immediately tell you if your problem lies before the filter or after it. Pressure should be 65 to 85 psi for an NA and 70 to 90 psi for a turbo.

And if you click on your name and then click on "view public profile" and then click on "about me" it states that your car is an 88FC. This has led to some of the confusion especially if your car is an 87 turbo.

 

is not the one way check valve built into the walbro pump?
if not where is it?

sorry i have not updated my profile for awhile. my old fc was an 88.

 

There is a diagram of the check valve location in the FSM.

 

ok... so i found the fuel cut and check valve and removed it. there are three lines going into it.

two small lines directly opposite of each other.
and a single larger line going into the bottom.

i can blow air thru it between the small lines in either direction.
cant blow or suck air thru the large line. nothing at all.

so how do i tell if its bad or not?

 

get a real fuel pressure gauge and tell us what your actual fuel pressure is. a bouncy needle doesn't tell us anything except you have cheapo unbuffered generic 100psi gauge installed.

 

its a b&m gauge. is that a cheap unbuffered one?

it never bounced around when my car was running and driving before.

just now that it wont hold fuel pressure.

 

if it's not oil filled then yes, it is cheap and unbuffered.

but even so if i were to guess i would say you have an internal leak at the fuel pump inside the tank, likely a split hose from the pump to the pump housing bleeding off fuel pressure back into the tank. take the pump back out and inspect your clamps, hose and double check that your power and ground connections are solid as well as the ground from the pump housing to the chassis of the car.

while there also check the sock, if it's dirty then clean or replace it. i find tons of rusty tanks lately causing all sorts of fuel pressure issues.

voltage being present doesn't mean much in my book.

 

+1
I had a split hose between the pump outlet and the pick up tube in the tank, it was a BITCH to tack down. It had all the symptoms of a leak, but I was never able to find any evidence of one. Finally I decided to swap pumps randomly (even though the pump that was in there was new) and thats when I noticed the slight crack in the line.

 

Ok i will double check that stuff. When I put the new pump in I replaced the hose and clamps from the pump to the tube. Any idea on the check valve?

 

forget the check valve, it is unecessary.

if anything i find that it is better for new cars but worse for older cars to hold static fuel pressure. leaky injectors? flooding issues. lower compression? flooding issues. i would rather crank the engine a few more seconds.