I want to test the regulator on my '89 before installing a fuel pump, but I cant find a rubber return hose to pinch off to test.

There are two hoese in front of the engine, but they are not really accessable. How have you guys done this?

 

Are you getting any fuel pressure? Have you looked into the vacuum line coming off the FPR for signs of fuel?

There are three lines that go to the tank.

Top right is the fuel feed line
Bottom right is the fuel return line
bottom left is the EECS vapor line

 

I get about 10-20 psi sometimes. Other tmes almost nothing. very inconsistent. Car wont start. Tries to, but quits almost immediatly.

At first, I had 35 psi. So I swapped the plugs, cap and rotor. They were all about 3-4 years old. Car got worse. rechecked the fuel pressure and it would not get me the 35 I had before.

I seem to smell gas. Would I get a fuel leak here? I can check when I get home in 2 hrs.

So the line I may need to squeeze is at the fuel tank? I'm looking at the engine. Wrong end of the horse perhaps?

 

I also had 35 psi on my 86 and it would not start, but I didn't attach the fuel pressure gauge good and it was leaking around it. If the diaphram in the FPR is ruptured, the fuel will leak into the vacuum line. In this case you will see fuel in the line, it will always smell like fuel in it. The lines you want to pinch off are at the top of the tank coming out of the fuel pump assembly.

 

Thanks!

I will check it carefully tonight.

 

RRT vette:
You sure about which line is which?

I get 20 psi on the fuel rail.

If I squeeze the top right line, I get 40 psi at the fuel rail. if I squeeze the bottom right, nothing happens.

Sounds like a need a new regulator. What ya think?

 

........

 

Yep, I'm sure which lines they are.

What was the procedure you used? Did you turn the key on and quickly pinch off the return line when the fuel pump stopped priming?

I haven't read much into your problem, but I would replace the fuel filter and make sure there are no kinks or restrictions in the fuel lines.

Apply 12v to terminal G of the ALDL, slowly pinch the fuel return line at the tank. The fuel pressure should go above 55 psi, but don't let the pressure go any higher than that.

If the pressure goes above 55 psi, then you have a faulty FPR.

If the pressure doesn't rise much if any, you have:

1. faulty fuel pump (check valve)
2. leaky or disconnected pulsator
3. resticted fuel pump strainer

Sounds like your problem is in the bold area. Most likely the fuel pump, strainer at the bottom of the fuel pump, or need more fuel in the tank.

Remember, the fuel pressure gauge reads psi. It doesn't know if it's fuel or air. The tank could be low on fuel and it's pumping air in the lines.

 

I use to check it at the front of the engine in my 86 by just reaching down with a pair of pliars. My gauge was on the passenger side of the plenum, so it was easy to monitor.

On the MiniRam II, the gauge mounts on the dirver's side, so I need someone to monitor it for me while I squeeze.

Jake

 

I'm thinking I am doing a crap job of testing this because I dont know what I am doing.

I cant get to the fuel line in the time it takes for the pump to shut off.

if your sure about the lines, then I am just squeezing the fuel in the line agaist the regulator and discharge check valve of the pump to get 40 psi. I will try to chack again.

 

You can run a 12v wire from the 'G' terminal on the Assembly Line Diagnostic Link under the dash. That'll energize the pump and keep it running while you run your test.

Just run a wire from the + post on the battery to the 'G' terminal on the ALDL; pump should fire right up and keep running.

Jake

 

See if you can get someone to help watch the gauge while you pinch off the line.

 

Thanks guys.
Got the wife to jumper the pump and watch the gauge while I squeezed the line. Got 25 psi out of the pump. But that was it.

Pump should be here next week.

Thanks for the help. I was getting frustrated. Worst part is not knowing what the heck your doing, and trying to do it.
Hopefully be drivein' next week.

 

.... ....looks like pump is history...(did ya ck the pump "sock" for restriction in the tank?)....

 

Havent pulled the pump yet. Figured I would wait to look inside Monday/Tuesday when the new one arrives.

I'm way behnd in my work load at the office, so I am hopeing to clear my desk a little before it shows so I can get on it. Working this weekend. Hard to work on the car when all I do is work at the office and shoot.

I bet the sock is nasty too with 18 years of crud. well see.

 

....well, if the sock is crudded up, that'll choke off the fuel flow for sure!

 

Don't be too concerned in the "not knowing" part. We've all been there before, just like I was recently when I re-built my first LT1 engine, which is considerably different from all the other SB and BB engines I've built.

Folks here have your back; they did for me.

Jake

 

I got the fuel pump in, it was an easy job.

Looks like the regulator is not holding pressure either. Turn the key, I get ~18 psi.

Start the car, I get 39 and it runs ok from what I can tell. Stop the engine and the pressure seems to bleed to zero fast.

Not sure what the deal is. I put in a racetronics fuel pump.
I'll see how it drives tonight.

 

There are three general areas where pressure could leak causing your reading to fall so quickly:

In the tank, in one of the fuel lines that run to and from the tank/engine, and/or the engine compartment itself.

If it's one of the lines or fuel filter, you'll easily be able to find it because there will be a stong gas small in the area of the leak and probably puddles or spray evidence.

If it's in the tank it's probably the pump's hose/line connection(s)

If it's at he engine it could be:

A leaking injector
The fuel pressure regulator
One or more of the injector "O" rings in the fuel rail or intake manifold
The connection of the fuel pressure or return lines to the fuel rails (here you'll see visual evidence of a leak).

When you shut down the engine, the fuel pressure should spike, hold at that higher reading and, then over time, gradually fall. The time it takes for the pressure to being to fall and the time it takes to actually return to ZERO varies.

After changing anything that calls for disconnecting any of the fuel components, like changing the pump, the very first time the pump is energized (engine not started) pressure will not rise to the normal level. On the second turn of the key - after waiting about 15 seconds or so - pressure should quickly climb to the pressure the regulator is set at.

Since turning the key without actually starting the engine only energizes the pump for about 2/3 seconds, not enough time passes to fully pressurize the fuel system.

Jake

 

did you replace the pulsator?