Fuel Pressure '86 S10

[Ray Hamilton]

I have a S10 2.8 with a Holley 502-3 TBI. I put it on a couple of years ago with no trouble except it always ran rich. But I have read that's normal.
I'm going to install a rebuilt 2.8, .040 over with a Edelbrock Performer grind cam, .420, .443 lift, 204, 214 duration, and a 3.1 crank and pistons. My manifold is bored to 4.3 gasket specs.
Will the Holley work w/o adjusting the regulator with the 3.1? I've never adjusted the regulator on the Holley. I understand it's behind the injectors. Would it be a good idea to get an inline pressure gauge? Which of the two lines is "in" and which goes back? I can just cut into the line and mount it that way can't I? Then adjust the Holley pressure regulator to what? 12 lbs is stock for the 2.8 TBI isn't it?

Geez, what am I thinking about, the line coming out of the filter is "in". Must've been too late at nite for that question.

[SappySE107]

I dont have any idea when it comes to TBI fuel pressure, but I wanted to ask what the 4.3 spec is exactly and if that is ok? Do you use the 4.3 gasket(s)? I don't know what gasket you are talking about but im not used to hearing 4.3.

[geoffinbc]

He means he has bored each bore of the manifold from 1 3/8" to 1 11/16" to fit the 4.3L TBI throttle body. It is common practice.

To install an inline guage is easy. You need to install a T somewhere on the pressure side of the system. This can be anywhere before the fuel pressure regulator. You can identify the supply side because it is a larger line. Normal systems range form 9 to 13 PSI. I myself would leave the presure where it is for the first run of the new motor then adjust from there.

[Ray Hamilton]

Thanks again for the information and replies. I figured 15 was plenty in as much as 9 to 13 is max. They must be warning against multiport 45+ or even a racing set-up. In-line is what I'll use, cheap, easy.

[jwvess00]

Hi there!

Here's a site that has a fitting that sits between the fuel line and the TBI. It adds a Schrader valve to the system to make it easy to test the fuel pressure.

http://www.toolsource.com/ost/product.asp?sourceid=mreferactron&dept%5Fid=500&pf%5Fid=95304&mscssid=8R3XV7XAH06N9NLDTNGXPXQC1UBG42SE