View Full Version : Fuel system help thread

08-23-2016, 06:25 PM
My st185 90-92 All Trac is cranking for around 6 seconds before firing when cold. Fires right away when hot. So need to start checking fuel stuff. Will crack open my Haines manual second I get home from work but for now...

What is more likely the cause? Fuel pump or regulator?

Where is the regulator? A: On or near the fuel rail.

Is there a check valve? Couldn't find on a search.

Does my car have a fuel return or return-less type system?

When replacing fuel pump is Bosch ok or just any OEM equivalent ok?


08-23-2016, 11:46 PM
If I remember correctly, the regulator is on the fuel rail on the end where the fuel line comes in. No check valve though.

As for a fuel pump, most people here are going to recommend OEM or a Walbro. The issue with the Walbro, as commonly mentioned, is making sure that you get a REAL Walbro pump. There are a lot of counterfeits out there. The turbo Supra pump is an upgrade as well and supposed to about as good as the Walbro. My personal opinion, buy a good quality pump, preferably from a name manufacturer. Dropping the tank is a pain so you don't want to do it twice.

I want to say that it has a return line but I don't remember for sure.

As for a cause, it could be either or it could be something else. Not much help there I know. Mine will do this sporadically and has done it for years.

08-23-2016, 11:59 PM
Does letting the system prime for a few seconds before cranking it help?

08-24-2016, 02:56 AM
Go with the supra TT pump (walbro 255lph). I had that on my swap and had no fuel delivery issues (well, except when I ran out of fuel and the gauge lied to me).

08-25-2016, 01:04 AM
If you're engine is maf, which I think it is, your fuel pump doesn't turn on until you start cranking and the maf gets air going through it. If you turn the key on and use your finger to open the maf you should hear the pump come on. It's a safety so if you wreck and the motor dies the fuel pump turns off. Check valve is the pump, kinda. It holds a little pressure. If your fuel filter is dirty the restriction will make it take a few extra seconds to build pressure all the way to the rail if it hasn't ran in a few hours, because fuel will slowly bleed back through the pump from gravity. Once you prime it back up again it probably works fine until it sits for several hours again.