Fuel pressure

[Opontee]

How much fuel pressure does my 94 3.4 need? And when you turn the key off, how long should it hold the pressure? I am fixin ta put a guage on it and need a starting reference point.

If it sits overnight and you try to instantly start it, it just crnks over. If you turn the key on for about 5 seconds and then try to start it, it start right up.

If you drive it for a while (like a hour), turn it off and let it sit for about 10 minutes, it just cranks before it starts, then it smells like raw gas, but then goes away. Has 273,000 miles and normally gets about 25 on the highway. Sometimes gets more-around 27,sometimes less, around 22.

Sounds like the injectors or regulator might be bad. This is what I am trying to figure out.

Thanks.

[cam98aro]

Re: Fuel pressure

that sounds more like a clogged fuel filter.

[Opontee]

Re: Fuel pressure

Changed in more than once. Cheap to do that. I did replace the pump new years eve 09.

[vanbibber]

Re: Fuel pressure

if i remember right it should be around 45-50 psi, ill have to look it up again but that sounds about right off the top of my head. sounds like the fuel pump is getting weak to me. dunno, the gauge should help find a starting point though.

[Opontee]

Re: Fuel pressure

OK, here is what happened. I hooked the gauge and had 38 at idle. Rev it up and it goes to 45. This is good. Turn it off and it goes to 0 in about 5 minutes. Hooked the gauge up to my wifes 98 Z with a LS1 and hers reads 50 at idle. Turn hers off and after about 15 minutes in drops down to about 40. This tells me that there is an iternal leak somewhere. I am sure that they are supposed to hold pressure longer than 5 minutes. So if any of you guys have a gauge and could check yours for me to see if it drops not running after a few minutes, I would appreciate it.

Thanks

[Rob Bell]

Re: Fuel pressure

It's probably the regulator. Those are the symptoms: Hard starting after it's been sitting, and a quick pressure drop after you turn it off. Pull the vacuum line and check for liquid fuel. This will confirm it's bad. However, an absence of gas in the vacuum line does not necessarily mean the regulator is good. It just means it has not sprung a leak to the vacuum side.

[Opontee]

Re: Fuel pressure

Thanks Rob.I will check the regulator again as I did a month or so ago. But it has been doing this for about a year. Autozone and Oreilly gets $67 for it and Advance gets $46 for it. HHhmmmm, wonder where I will buy it at. They all sell the same brand.