Fuel Pressure Regulator Options

[Sea Dragon 914]

So this weekend I was working on one of my cars. It has a high idle and shuts off after the engine idles for about 15 minutes and won't keep running again until it cools off. The fuel pump has been relocated near the steering rack.

I put a pressure gauge on it and it was running 55-60 pounds of pressure. (IMG:style_emoticons/default/blink.gif) I think that might have contributed to the high idle. I adjusted the regulator to about 30 psi. Unfortunately for me, it started leaking. Can I unscrew the adjustor and use plumber's tap to seal it back up or do I need to get a new regulator.

Also, is there anything other than the fuel pump that would cause the engine to shut down when it warms up?

Thanks

[SirAndy]

Also, is there anything other than the fuel pump that would cause the engine to shut down when it warms up?

Stock D-Jet?

If so, the CHT sensor can cause that when going bad or having a bad connection.
(IMG:style_emoticons/default/idea.gif)

[BeatNavy]

Can I unscrew the adjustor and use plumber's tap to seal it back up or do I need to get a new regulator.

It handles fuel. I wouldn't screw around with that, and I'm no plumber, but I imagine plumber's tape is not designed for gasoline - probably break it down pretty quickly. Get a new one - they're plentifully available new or used.

Also, is there anything other than the fuel pump that would cause the engine to shut down when it warms up?

With the fuel pressure almost double what it should be you are probably flooding the engine as it warms up. It sounds like it may work while the engine is cold, but the engine needs a much leaner mixture as it warms up or else it will die from being overly rich. The injectors are squirting a LOT more fuel than needed each time they are triggered due to the pressure. The high idle may be a vacuum leak (or normal function of AAR), either of which may sort of compensate for the overly rich mixture up to the point where it's too rich and the car dies.

You may have fixed your problem by readjusting the pressure to spec (assuming you get a working, non-leaking pressure regulator).

Or, if that's not it, as SirAndy mentions, perhaps the CHT.

[stugray]

Can I unscrew the adjustor and use plumber's tap to seal it back up or do I need to get a new regulator.

No - if it is leaking past the adjustment screw then the unit is leaking internally.
I dont know how the stock unit works, but modern pump gas with ethanol destroys the rubber diaphragm in the Holley Carb regulators I use for carbs in just 2 years.

If the stock unit has any rubber parts inside (and you are using ethanol "spiked" gas) it is probably shot.

I have at least 5 FI pressure regulators.
Post a pic of yours and I'll send you one (if I have a match).

[Sea Dragon 914]

Thanks. I'll order a new one. I think they run about $60.

It is D-Jetronic. You are talking about the Head Temp Sensor, correct? I'll give that a try. Hopefully I'll be able to get the thing out. I've had issues replacing them in the past and I'm not sure how long that one's been in there.

[porschetub]

Can I unscrew the adjustor and use plumber's tap to seal it back up or do I need to get a new regulator.

It handles fuel. I wouldn't screw around with that, and I'm no plumber, but I imagine plumber's tape is not designed for gasoline - probably break it down pretty quickly. Get a new one - they're plentifully available new or used.

Also, is there anything other than the fuel pump that would cause the engine to shut down when it warms up?

With the fuel pressure almost double what it should be you are probably flooding the engine as it warms up. It sounds like it may work while the engine is cold, but the engine needs a much leaner mixture as it warms up or else it will die from being overly rich. The injectors are squirting a LOT more fuel than needed each time they are triggered due to the pressure. The high idle may be a vacuum leak (or normal function of AAR), either of which may sort of compensate for the overly rich mixture up to the point where it's too rich and the car dies.

You may have fixed your problem by readjusting the pressure to spec (assuming you get a working, non-leaking pressure regulator).

Or, if that's not it, as SirAndy mentions, perhaps the CHT.

Good points made here Rob,I wouldn't run a HP fuel pump with a regulator for starters,they simply aren't designed for it,I would suggest the OP buys the correct pressure pump,by cutting back delivery pressure with a regulator the pump will fail in due course.
The same thing happens when a HP rotary with a blocked fuel filter,been there and seen it.

[stugray]

Can I unscrew the adjustor and use plumber's tap to seal it back up or do I need to get a new regulator.

It handles fuel. I wouldn't screw around with that, and I'm no plumber, but I imagine plumber's tape is not designed for gasoline - probably break it down pretty quickly. Get a new one - they're plentifully available new or used.

Also, is there anything other than the fuel pump that would cause the engine to shut down when it warms up?

With the fuel pressure almost double what it should be you are probably flooding the engine as it warms up. It sounds like it may work while the engine is cold, but the engine needs a much leaner mixture as it warms up or else it will die from being overly rich. The injectors are squirting a LOT more fuel than needed each time they are triggered due to the pressure. The high idle may be a vacuum leak (or normal function of AAR), either of which may sort of compensate for the overly rich mixture up to the point where it's too rich and the car dies.

You may have fixed your problem by readjusting the pressure to spec (assuming you get a working, non-leaking pressure regulator).

Or, if that's not it, as SirAndy mentions, perhaps the CHT.

Good points made here Rob,I wouldn't run a HP fuel pump with a regulator for starters,they simply aren't designed for it,I would suggest the OP buys the correct pressure pump,by cutting back delivery pressure with a regulator the pump will fail in due course.
The same thing happens when a HP rotary with a blocked fuel filter,been there and seen it.

Umm, I assume the OP is talking about the stock Fuel pump with the stock pressure regulator.
Which pump is it you think was not designed for a regulator?

[Sea Dragon 914]

Yup. All stock for a 2.0. I just ordered a new pressure regulator and will try to change the Head Temp Sensor this weekend.

[BeatNavy]

Yup. All stock for a 2.0. I just ordered a new pressure regulator and will try to change the Head Temp Sensor this weekend.

Before you change it, have you run the car with correct fuel pressure? Also, test the CHT first. Check the resistance from the lead to ground to see if it's in specs. Inspect the wiring. It certainly COULD be the problem, but hate to see you change it if it's not.

[pbanders]

Yup. All stock for a 2.0. I just ordered a new pressure regulator and will try to change the Head Temp Sensor this weekend.

Have you tested your CHT? It's easy, just measure the resistance to ground when it's cold, should be 2200 ohms or so. When it's hot (30 minutes of driving in warm conditions), it should be 100 to 200 ohms at most. If it reads like that, don't change it.

While you're at it, why not check all the components in your FI system, now that you have the correct fuel pressure? All the checks are on my web page in my sig.

[Sea Dragon 914]

Great info and I'm bookmarking your website.

When the new pressure regulator arrives, I'll install and adjust it. Tonight I'll measure the resistance of the CHT.

[stugray]

Have you tested your CHT? It's easy, just measure the resistance to ground when it's cold, should be 2200 ohms or so. When it's hot (30 minutes of driving in warm conditions), it should be 100 to 200 ohms at most. If it reads like that, don't change it.

While you're at it, why not check all the components in your FI system, now that you have the correct fuel pressure? All the checks are on my web page in my sig.

In fact, to rule out a CHT problem, you can just connect that wire to ground via a 100-200 ohm resistor and the ECU will think the engine is warm.