No longer wants to start...suspect fuel pressure.. recommendations?

[rearden]

I have a '88 B2 with the 2.9 EFI V6. It was my daily driver; I stopped driving it for a few weeks and it now refuses to start.

The engine will turn over and try to catch.
I put a fuel pressure gauge on the rail under the hood. I can hear a fuel pump running and the pressure holds stead at 45psi or so with the key on, but not cranking. When I crank, the pressure drops quickly to single digits, but will go back to 40+ when I go from start to on.

Any ideas on the part I need to replace?

Rearden

[jhammel85]

The fuel pressure sounds OK but I'm honestly not sure if mine drops to single digits JUST before it starts or not.

If it is unusual for this, I would suspect that the Fuel Pressure Regulator is bad. Frankly, it sounds fine to me.

I would check other routes 1st. How is the spark? Did you move any spark plug wires or mess with the timing? Everything plugged in as it's supposed to? Grounds all good? Any codes in the computer?

[rearden]

Everything should be plugged in, it ran fine until I parked it.

I have been unable to pull codes. I put the jumper wire on the self test connector but I can't get the lights to flash or the voltage to sweep.

It wants to start. In fact it will begin to start, as in enough cylinders fire that you think it is started and let off the starting key and it promptly dies. If I continue to hold it, it will still want to start but never enough to keep going.

How do you replace the fuel pressure regulator? I haven't found that in the Haynes manual.

rearden

[alwaysFlOoReD]

I don't know enough to give definitive help, but I would suspect a wiring problem in the cranking circuit - to the fuel pump. Look at a wiring diagram. I know, I know, they are hard to decipher, but you have to start somewhere. Or trace the wires looking for damage.
Good luck,

Richard

[rearden]

I poked around some more.

When I start it the fuel pressure steadily goes down until it is basically zero. As soon as I let off the starter, it returns to the 45 range.

I pulled the vacuum hose off the back of the fuel pressure regulator and it was filled with gas. When I tried starting it while it was disconnected, it spurted fuel when I released the starter.

Before I try to pull unnecessary parts off ... does this mean the fuel pressure regulator is the culprit?

rearden

[alwaysFlOoReD]

Yes

[masterelyt]

Maybe your timing has moved?

[rearden]

Last weekend I replaced the fuel pressure regulator, but no cigar. Something was wrong with it because there was a lot of fuel in the vacuum hose side of regulator, but changing it did not solve the problem.

As for timing, it could have shifted, but the is no reason it should have, as in the hood wasn't up between starting and not starting periods.

It will begin to start as long as the key is in the start position and give some muffled pops, but the fuel pressure quickly tends to zero and as soon as I let up off the starter it shuts off.

Additional ideas?

rearden

[kimcrwbr1]

Sounds like a bad ignition switch, with the key on run do you have power to the coil, that will also turn off the fuel pump if the engine dont start.

[kimcrwbr1]

Also if the fuel pressure drops quick after you cycle the ignition it could be a leaky injector/s flooding the engine. smell your dipstick for fuel. with the pressure guage on the rail cycle the key without starting it it should hold pressure especially with a new regulator or it could be a bad check valve in the fuel pump. You did put a new fuel filter on right.

[hduncan2587]

This thread might come in handy for me over the next couple weeks, so bump.

My issues on our 95k Cologne is the battery and relay are new. Battery last week, and relay this summer.

Sometimes the starter will just click, other times it will grind, other times it will do both. Other times it'll make a "doink" sound which I'd assume is hitting the flywheel. And finally, other times it will sit there turning, but not actually starting.

I'll try and get this stuff on Youtube next time it does it, that way you guys can hear all the different stuff it does and maybe use it as a template for the different sounds, and what they mean.

[MJ'sBlkBII]

Have you checked both pumps? Remember, you have 1 intank (low pressure) and 1 on frame (high pressure). If one is out it may be able to prime on key on, but not maintain for the crank. Also check fuel filter and the inline bowl (can't recall the name) that I belive is between the high pressure pump and the fuel filter. If you had fuel in your vacuum line to the pressure regulator it was bad. That means the diaphram was leaking. Spray a bit of starting fluid in the thottle body as you crank to see if it will fire on that.