Fuel pressure question - FPR

[Silver85TC]

I've been noticing that my car seems to run quite rich after a cold start (Very strong gas smell from exhaust for the first few minutes) It also occasionally idles a bit rough when cold. Once the car warms up and is in closed loop, the rich smell goes away and idles quite smooth.

I replaced my fuel pump last spring with a 190 lph unit (old one packed it in). All the tuneup parts under the hood are new/cleaned. The car is basically stock (cat back/advanced timing). As far as I know, the FPR is original.

I checked my fuel pressure this morning (cold start). The fuel pressure at idle was 44 psi with the vacuum line on, and 36 psi with the vaccum line off. This seems a bit high to me. It could also account for the rich condition at cold idle.

I just want a confirmation that it's worth while installing a new FPR (I hate changing parts randomly!). My thinking is the new fuel pump is overpowering the old stock FPR.

Opinions appreciated.
Thanks

 

[TrueBlue95GT]

I'm guessing you mean the fuel pressure was 36 with vacuum on and 44 with vacuum off. Yes, that is high. I would recommend getting a new FPR also.

 

[Silver85TC]

Oops, you're right, other way around with the vacuum on/off. lol

I should also mention that my maintenance manuals say spec fuel pressure at idle is 30-45 psi. So technically, I'm within spec. As I said previously though, I think 44 psi at idle is too high on a stock machine.

 

[TrueBlue95GT]

If I'm not mistaken, fuel pressure should be at 39 psi with vacuum off for the stock FPR.

 

[go-stang5.0]

You can try just changing the fpr since there cheap...or you can get an adjustable one. I always thought that when they went bad they went all out....and just dumped way too much fuel but i guess i could be wrong. Try it and see what happens...worst case scenario you can clean it out real good, return it and get an adjustable one.

 

[Silver85TC]

Thanks guys. That's what I thought. I'm going to change it out. I'll let you know if the fuel pressure drops a bit.

Cheers

 

[stang_gt_1994]

How cold of weather are we talking about? The PCM is designed to dump extra fuel at a cold startup. It helps because fuel does not atomize as good when cold.