As I continue to figure out what could be the problem. I was getting 70psi @ idle with 12:1 FMU connected so I disconnected the FMU to see what is the stock/base fuel pressure. FYI, I'm running 255lph fuel pump and 12:1 FMU for fuel setup for my custom stage 2. Here are the numbers I got during idle based on my gauges and ScanGageII:

- fuel pressure still reading 70psi @ idle even after FMU was taken out? WTF? electronic fuel gauge hooked up wrong/broke?

- 16-20 vacuum

- 400 egt

- 860rpm idle

- voltage @ 13.6 v

- throttle position sensor is @ 10

- intake air temp @ 101F~ish

- ignition timing @ 45~ish

- manifold absolute pressure @ 5.4 - 6~ish

- and a PO412 CEL!

It would have been better if our ECU reports FPR but it does not and Scan Gage II can display it.

Do you guys think using 3/8"(6AN) fuel hose instead of 1/4" (4AN) would fix the pressure problem?

Not sure why you started a new thread. But if your idle is at 70ps1 with only the stock FPR then your fpr might be dead. Are you sure your fuel pressure readings are accurate?



This is why I use the search button.

Originally posted by DarkOne
You're fine. Everything is fine. Your EGT vacuum level fine. Theres sunshine and birds and dancing and shit going on everything is so fine. YAY! What the fuck are you talking about?

Originally posted by hs_elrod
Not sure why you started a new thread. But if your idle is at 70ps1 with only the stock FPR then your fpr might be dead. Are you sure your fuel pressure readings are accurate? This is why I use the search button.

Originally posted by DarkOne You're fine. Everything is fine. Your EGT vacuum level fine. Theres sunshine and birds and dancing and shit going on everything is so fine. YAY! What the fuck are you talking about?

How accurate can you get those readings? I ran the car on idle at least twice with the FMU on and off. I think its the fuel line size being too small that is causing the high fuel pressure.

Before you bring up the search button, you are freakin' clueless how much I used that feature, did you even look how many posts I have for being a member here since God knows when? Having an early '95 fuel system makes it a little tough to find solutions sometimes.

I haven't read your other thread in depth but have you checked your fuel supply line for clogs or kinks in it? If you are still reading fuel pressure that high at idle even with the factory FPR instead of the FMU it would seem like it would either have something to do with the fuel lines or your gauge is messed up somehow. Do you know anyone who lives near you that could let you try out their fuel pressure gauge for a couple minutes to test it?

I still don't know why people still play around with a FMU when SFMU units have been proven to work wonders. Check for kinks like others have suggested, and you did remove the stock regulator right?

Originally posted by eclipsekaiser
I still don't know why people still play around with a FMU when SFMU units have been proven to work wonders. Check for kinks like others have suggested, and you did remove the stock regulator right?

Funds are limited that's why I had to go with the FMU for now and the stock FPR does not get removed. I removed the 1/4" (4AN) fuel lines and will replace them with 3/8" (6AN).

You may have to disable the stock fpr like this to get your fuel pressure down. http://www.2gnt.com/www/corbin/fpr.html

Or if you want I could modify your stock fuel rail to accept AN or nipple fittings. It will be simular to the one I put on my car, but instead of the weld on AN fittings it will have 3/8 NPT on each end of the rail. That way you can put in what every size or type of fitting you want.

His FMU can't regulate idle fuel pressure so if he disables the stock FPR, weird shit will happen. I'm still saying you should get a mechanical fuel pressure gauge just to test the accuracy of your electric gauge. If you drove the car around without any problems with this really high fuel pressure, it can't be that big of a deal.

Originally posted by BumpinTalon
His FMU can't regulate idle fuel pressure so if he disables the stock FPR, weird shit will happen. I'm still saying you should get a mechanical fuel pressure gauge just to test the accuracy of your electric gauge. If you drove the car around without any problems with this really high fuel pressure, it can't be that big of a deal.

I completely agree. Thats why I went with hahn's crappy, but functional, rising rate regulator made my corky bell. It has two functions. One that I didn't find on the regular FMU's is an idle fuel pressure adjustment.

The fmu only raises the fuel in accordance to how much boost is in the lines. If you want to regulate idle pressure, you're going to have to get another unit for that.

Also, if you're boosted, you HAVEEEEE to take off the factory pressure regulator behind the passenger side rear tire. If you don't, when you're boosting, fuel pressure will not rise above 60 Psi. I did this for a while, and went through 3 fuel pumps before I realized the whole time that it was because of that.

Originally posted by 420agreenvilleSC

Originally posted by BumpinTalon His FMU can't regulate idle fuel pressure so if he disables the stock FPR, weird shit will happen. I'm still saying you should get a mechanical fuel pressure gauge just to test the accuracy of your electric gauge. If you drove the car around without any problems with this really high fuel pressure, it can't be that big of a deal.

I completely agree. Thats why I went with hahn's crappy, but functional, rising rate regulator made my corky bell. It has two functions. One that I didn't find on the regular FMU's is an idle fuel pressure adjustment. The fmu only raises the fuel in accordance to how much boost is in the lines. If you want to regulate idle pressure, you're going to have to get another unit for that. Also, if you're boosted, you HAVEEEEE to take off the factory pressure regulator behind the passenger side rear tire. If you don't, when you're boosting, fuel pressure will not rise above 60 Psi. I did this for a while, and went through 3 fuel pumps before I realized the whole time that it was because of that.

with the fmu the stock fpr should still be connected . also he had a 95 ,it is not in the back of the car its on the rail

Originally posted by BumpinTalon Also, if you're boosted, you HAVEEEEE to take off the factory pressure regulator behind the passenger side rear tire. If you don't, when you're boosting, fuel pressure will not rise above 60 Psi. I did this for a while, and went through 3 fuel pumps before I realized the whole time that it was because of that.

I have a 1995, our FPR are on the passenger side end of the fuel rail.

Originally posted by BumpinTalon
His FMU can't regulate idle fuel pressure so if he disables the stock FPR, weird shit will happen.

Ah, I forgot that you can't adjust static fuel pressure with the fmu.

Originally posted by MiztahfooLish

Originally posted by hs_elrod Not sure why you started a new thread. But if your idle is at 70ps1 with only the stock FPR then your fpr might be dead. Are you sure your fuel pressure readings are accurate? This is why I use the search button.

Originally posted by DarkOne You're fine. Everything is fine. Your EGT vacuum level fine. Theres sunshine and birds and dancing and shit going on everything is so fine. YAY! What the fuck are you talking about?

How accurate can you get those readings? I ran the car on idle at least twice with the FMU on and off. I think its the fuel line size being too small that is causing the high fuel pressure. Before you bring up the search button, you are freakin' clueless how much I used that feature, did you even look how many posts I have for being a member here since God knows when? Having an early '95 fuel system makes it a little tough to find solutions sometimes.

Dude thats just my sig, no offense intended.

This is why I use the search button.

Originally posted by DarkOne
You're fine. Everything is fine. Your EGT vacuum level fine. Theres sunshine and birds and dancing and shit going on everything is so fine. YAY! What the fuck are you talking about?