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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-

Fuel Pressure Loss

  • Thread starter Thread starter Ricco Suave
  • Start date Start date Oct 7, 2023
R

Ricco Suave

Member
Oct 7, 2023
3
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13
Vancouver
Oct 7, 2023
#1
  • Oct 7, 2023
  • #1
Hi
I'm new here and new to Mustangs in general so be easy on me
My back ground is more Turbo BMW's but I've always wanted a foxbody so..
Its an 87 notch back
I bought it the way it is so I'm not sure of some of the mods
Trick Flow intake
I know the cams have been done
Vortech Supercharger (Intercooled)
Mega Squirt 2
I have no idea at the moment what size injectors
He gave me a list of all the mods but I can't find it right now

Here is my problem
I start the car and its surging, surges every time I come to a stop
When I step on the gas it feels like its going to die at first then if I kind of pump the gas a bit it comes back
For the first 10 mins the fuel pressure runs about 40-42 (There is a gauge in the pillar)
Then is starts to fall off to 30 then down to 15-20 within a couple mins making it undrivable
When I bought it he told me there was a problem with the fuel pump
He had just replaced it but went with a cheaper one, Qualcomm.
So I replaced it with a Walbro
Size on the fuel pump I took out was 525 so that's what I replaced it with another 525 but it seems like a bit of overkill to me considering some of the numbers people are putting down with smaller pumps
Problem was fixed for about 2 days then it happened again
I replaced the relay at the pump when I replaced the pump as well
There is an adjustable regulator up front that looks a little weathered but I don't know
The surging happens even when the pump is running at 40
When I had my 135i the intakes got dirty and needed to be walnut shell blasted every so often and the car surged although not as bad but this feels more like a vac leak or maybe its related to the fuel problem
If i let it sit for a day and start it back up it runs at 40 again for 10 mins at least

So I guess I'm looking for a little guidance or someone to point me in the right direction cuz at this point I seriously considering drooping an LS into it because I don't want to have to cut to fit in a coyote but I don't want to drop 5 grand into replacing things hoping it will fix the problem when I can just put a new motor in for 10
Do I need to run a 525 pump?
The wiring on this thing looks like it was done by a drunk monkey I have plans to spend the winter cleaning it up plus I want to do a little bit of a sound system in it so I have already ordered a Mechman 240 amp alt and a titan lithium battery
Could it be electrical?

I can post pictures of the engine if it makes it easier

Thanks for any help in advance

On a side note, those of you with notchbacks, those bars in the trunk that run between the hinges under the deck lid
Are those just to hold up the trunk lid, can I get rid of them and put in hydraulic
It's a perfect little spot to subs
 
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