Fuel pressure gauge explodes

[Ineedboostman]

Cars fuel pressure is 40 at idle. Drops down to the 30s at hot idle. I was driving the car home and started to smell fuel. Found the glass on the fuel pressure gauge exploded. Bought I new Marshall liquid filled gauge. I've had it on the car for a little over a week and I noticed the liquid is getting pushed out of it. The needle broke off and there is only a little bit of fluid left in it. Only thing I can think of is high pressure but the cars running good. Any thoughts?

 

[9!'clipseDOHC]

How much boost are you running and what type of AFPR?

Your fuel pressure is supposed to raise 1 psi for ever psi of boost, for instance a base fuel pressure of 40 psi plus 20 psi of boost you should be seeing a max of 60 psi of fuel pressure.

Most fuel pressure gauges aren't meant to be left installed in the bay. They are supposed to be used to set the pressure and then removed with the port plugged. That said, it should fail after a week of use. I left a B&M gauge installed in the engine bay for several years once and never had any problems.

 

[Ineedboostman]

I bought the regulator attached to the rail from someone locally. Not sure the brand, doesn't say. Has an edelbrock elbow that a pro comp gauge is screwed into. I'm only running 7lbs. Wanted to turn it up this week but not till this is resolved. When the first gauge blew I had just put a plug in it and it ran fine. Put the new gauge on now I'm having this same issue.

 

[dsmTripp]

What about running an electronic fuel pressure guage that way you can monitor it and not have the chance of blowing it

 

[9!'clipseDOHC]

You need to know the type of regulator you are using. It has to be a 1:1 rate regulator so that the pressure increase 1 psi for every 1 psi of boost.

 

[Ineedboostman]

Electronic would cost alot of money I'm not looking to spend. I thought there's was only two types of regulators. A set rate and rising rate. If the one I have was set then I would go lean under boost correct. AFR at 12.5 under boost. Runs real good. Guess I'll see if I can get a gauge to use in the car to figure out this issue.

 

[LiquidX]

OP, I feel your pain. For the longest time the Aeromotive gauge I had in the bay lasted for a while. Once I had my last rebuild and have been battling temps, all 3 gauges I've used have had the plastic face hazes out after a couple days. The plastic became brittle and the gauge stopped working.

 

[Ineedboostman]

So liquidx did you figure it out? Was it from high engine temps. My car shows normal on the gauge and via link. Idk what else to do besides buy a new regulator.

 

[LiquidX]

Nope, I just have a plug installed for now. If I need to check the pressure I'll go buy a new gauge and install it just for testing the pressure then remove it.

 

[Ineedboostman]

Guess I'll just do the same.

 

[9!'clipseDOHC]

Electronic would cost alot of money I'm not looking to spend. I thought there's was only two types of regulators. A set rate and rising rate. If the one I have was set then I would go lean under boost correct. AFR at 12.5 under boost. Runs real good. Guess I'll see if I can get a gauge to use in the car to figure out this issue.

There are more then just 2 types of regulators. What you commonly see on our cars are 1:1 fixed rate regulators. But that doesn't mean that they are the only ones out there. There are 2:1, 3:1, adjustable, true raising rate regulators, etc. That is why I said you need to know what is on your car. You have no idea what a previous owner may have slapped on there. Here is an explanation from 3si.org:

Alright boys. First off our cars use a "fixed rate" FPR or even a "steady rate" FPR. It is fixed at 1:1. Some people do call this a rising rate FPR but they are usually pretty ignorant as to what a real rising rate FPR is. Rising rate regulators go up at a different rate than 1:1 based on how much boost they see (meaning at 0psi it might be 1:1, at 3 psi it might be 5:1, and at 7psi it might be 12:1 ... hence rising rate) and their purpose is almost always for non-boosted ECU's with a MAP sensor ... because there really isn't any other way to tune such a setup.

You will not find too many true rising rate FPRs on MAF cars because they don't need them ... a simple S-AFC is sufficient and will give you far better tuning. So basically we have no need of a rising rate FPR, a fixed rate 1:1 FPR is sufficient.

For the record I personally have installed and tuned a 16G on an N/A neon and I have first hand experience with using a true rising rate FPR to tune with and it works great. Under vaccuum (off boost) the rail pressure was like 20psi at most but under boost it would go up to 50-60psi. Some people DO run 90-100psi and it works fine. When you have to turn off your MAP your only option is to tune via fuel pressure.

 

[Ineedboostman]

Thanks for clearing that up

 

[Colt4G63 also]

$48 for an electric 0-100 psi fuel pressure gauge, with free shipping. Then you'll know what's going on for once, and forever after.

Tinted 100 PSI Fuel Pressure Gauge

 

[Ineedboostman]

I'm goin to pick up that gauge. I'll update once I get it.