*Updated info*
long story short the car stumbles and stalls sometimes at hot start-up and is running rich. Raw fuel smell sometimes after shutting off, not sure about while starting.

I've got a fuel pressure gauge on it and am leaving it on all weekend to keep watch, but here's what I've gotten so far.

Hot idle: steady 32 psi
Turned off hot: steady 37 psi for at least 20 minutes
During stumble at hot start up: steady 32 psi
After sitting for a couple hours: currently around 20 psi

Cold Start ups: no stumble, starts right up no problem

Anything of note from these results?

I'm not sure how it could be related, but I think my brake booster diaphragm is toast - because whenever I apply pressure to my brakes it sounds like I'm airing down a tire. Brake's work fine like normal and pedal is normal, doesn't go to floor and isn't stiffer than normal. Any possible relation?

Also, I have a tick when warmed up and under load, the tick speed and loudness parallel heat and load (acceleration).
DIIB

 

If on your D1 there is a fuel pressure test point on passenger side fuel rail, attach guage and look for 32-34 psi. FPR is on driver side rail at rear, ahs very short vacuum hose. On D2 the test port is on driver's side rear corner under the intake manifold and the FPR is par of the fuel pump in the tank.

 

Thanks, and yes this if for the D1. Question: will a tire pressure gauge be sufficient? And obviously I'm going to want to check this at warm start up right?

 

You could also rent/borrow/refund a gauge from many auto parts stores. Could just test in parking lot. Key on, pump runs for a few seconds and PSI shoots up, crank, and hopefiully it stays above 30. Could be clogged fuel filter (over passenger side rear tire inside the wheel arch.

 

Sounds like leaky injectors. You can buy a gauge at pepboys for $30 or so, not like you won't use it again to diagnose your rover. You could just try pushing the schrader valve in after it sits for 15 minutes or so, if fuel dribbles out instead or spraying it's clear the rail isn't holding. Then it's on to figuring out what's causing it.

 

Well, I put on a proper gauge this morning after driving for a while and started her up, though unfortunately it must not have been hot enough because it didn't stumble like it normally does on a warm start.

The fuel pressure was steady at/around 30 psi. I might try and check it again while it actually stumbles at hot start-up.

What result would suggest I need a new fuel pressure regulator?
What should I check next?

Thanks in advance, DIIB.

 

Do you have a vac pump? You can check the FPR. First check the vac hose that runs to the plenum, see if it's in good shape and not falling apart. Put a vac pump (Mityvac) on the FPR and pump it up, if it holds vac the diaphram is probably good. With it running watch the pressure gauge as you pump up the vac pump, fuel pressure should drop. Release the vac and pressure should rise. Also note what the engine does during this, high rail pressure at idle will cause it to run rich because engine vac actually pulls the fuel out of the rail through the open injector.

The FPR does not actually "regulate" fuel pressure, it regulates the pressure differential in the rail. It's a basic valve, allowing more fuel to return to the tank during high vac(idle), and holding more fuel in the rail during low vac(acceleration) to meet the engines demand.

30psi is a tad low, have you replaced the fuel filter recently? Ever?

 

Thanks for the info.

Fuel filter? No, I haven't personally in the year i've owned it.

FYI - the car is running a little rich from what I can tell and smell.

 

Did a little tune-up this weekend, have had plugs & wires sitting the back of the truck for a while now, and had never changed the fuel filter (think it was OEM).

8mm Kingsbourne's & champion coppers - much more responsive and consistent power. The truck has been a little rich for a while, but the champions I took out looked pretty good still, though obviously not gapped...and I didn't gap the new ones either, sue me.

Purolater fuel filter - this might help my stumble at warm start-up issue, not sure yet, but either way I had never done it and don't know if it ever had been, couldn't hurt.

P1178 (I think) came up one morning last week but never showed it's face again, we'll see if she returns.

Next up, check fuel pressure again and look for vacuum leaks.

 

The fact that you have to "give it gas" to get the stumble to clear up is a sign fuel is leaking through the injectors into the cylinders. You actually aren't giving it gas, you are giving it more air to help burn the excess fuel. P1178 often shows up shortly before the fuel pump pukes.