View Full Version : When is a fuel regulator actually needed to be modified?

03-27-2011, 08:06 PM
I have been storing parts for when it gets warmer, so I can start playing with my gmc. I have all kinds of tbi stuff in parts and alot of files pertaining to the regulator modification to make it adjustable. Every thing out there states that this is done on your own, but it doesn't really state when stuff like this is needed. I'm also got an exhaust in parts in the garage too. headers (from a buddy's International Harvester with a 350) a couple of 2.5" in and out glass packs, but now cat.

So when do I actually need the regulator to be adjustable, after I install the spacer plate? Or after I do the exhaust with the spacer plate?

I do have the dodge as a backup DD, I wouldn't dream of playing with the computer, motor stuff and not know what it will do to the daily use of the system

03-28-2011, 09:34 AM
It really only needs to be adjustable when your running to lean and can not tune it richer in the chip.

Turning up the pressure increases the fuel to richen the engine.

03-28-2011, 07:35 PM
I guess I was shooting for a different marker and didn't face the question towards that direction. I have seen on different forums where after say two exhaust mods then you'll need to adjust fuel pressure, or after a spacer and matched injectors, for example. My motor is an 89 350, the infor I have seen for the factory states that they left the assembly line between 11-13 psi. In the late 80's I can understand that but in today's world, is there a rock hard number that these motor are to run on? Secondly should I start with the computer before I add on the warm weather toys? I have always wanted to play with the computer, but until recently I haven't been able to (family stuff).

03-28-2011, 08:01 PM
They may be trying to add fuel presure to tune because they don't have tuner equiptment?

Best running TBI engines I have seen, stock are at 13 PSI. But with a cheap gauge that read from 0 to 100 it may only say 12. I think that's why the numbers always vary. My gauge is for TBI and goes from 0 to 20 I think So you can see how it would be more accurate.

There's plenty of room to tune in the ECM before you need more fuel and it will cover all the mods until you get to head work, cam, intake etc... easier way to say that would be bolt on mods can and should be chip tuned to get all the power out of them.

03-30-2011, 05:39 PM
So using headers, a tbi spacer and an air intake won't require a major (if any) mod of the original program?

I am assuming that it would be a good idea to get a baseline of the engine without anything (completely stock) added before beginning with even the air intake?

03-31-2011, 03:20 AM
Bottom line is, when you have consistently high BLM/INT numbers, high WB o2 readings or lean plug reads & have no way to alter .bin files you may be able to force a richer mixture with more fuel pressure.

Note that this is not the way to optimize fueling, just a method of getting by until you are able to develop tuning resources.