$OD A/E Help

[Rally Smith]

Alright, you don't know what you don't know till you know. Or something like that. So my GoPro finally came in handy today. Looks like when I get on the throttle (not to the floor) it goes from a little over 14psi DOWN to 10 or a little less. That makes sense why I'm going so stinking lean. So other than installing a TPI fuel pump what are my options at this point? The less I spend the happier the woman will be with me. Thanks.

[fastacton]

I don't think there is another option except for pump replacement. It looks like yours just isn't up to the task anymore.

[Rally Smith]

I don't think there is another option except for pump replacement. It looks like yours just isn't up to the task anymore.

With that other fuel pump, do you think the stock regulator style on the TBI work well enough with it?

[Six_Shooter]

When's the last time you replaced the fuel filter? Have you done a dead head test yet?

You need to do some more testing before you replace parts, to make sure you're replacing the correct parts. ;)

[Rally Smith]

When's the last time you replaced the fuel filter? Have you done a dead head test yet?

You need to do some more testing before you replace parts, to make sure you're replacing the correct parts. ;)

Fuel filter probably a year or so ago. I have no clue whet the hell a dead head test is? Please take me to school.
I'm all for testing before throwing money around!

[Rally Smith]

O.k. did some searching. I will plug off the return line and see what it does. Will this be dangerous to have the return line blocked off?

[Six_Shooter]

I would be lying if I said it's in no way dengerous, but as long as you take the proper precautions, you will be fine.

I like to just clamp the return line when I can, only do this with rubber return lines, not the braided lines that some GM TBI systems are equipped with.

[Rally Smith]

I would be lying if I said it's in no way dengerous, but as long as you take the proper precautions, you will be fine.

I like to just clamp the return line when I can, only do this with rubber return lines, not the braided lines that some GM TBI systems are equipped with.

I have the braided lines, what would you suggest?

[fastacton]

With that other fuel pump, do you think the stock regulator style on the TBI work well enough with it?

As long as you have an unrestricted return line, you won't have any problem with the stock regulator. Since your fuel filter isn't too old, it's probably not an issue, but may still be. You might be able to just go with a stock replacement pump instead of upgrading, yours might just be getting worn out. I do prefer to have an overpowered pump rather than possibly going lean at the wrong time, though.

[Rally Smith]

As long as you have an unrestricted return line, you won't have any problem with the stock regulator. Since your fuel filter isn't too old, it's probably not an issue, but may still be. You might be able to just go with a stock replacement pump instead of upgrading, yours might just be getting worn out. I do prefer to have an overpowered pump rather than possibly going lean at the wrong time, though.

Got a pump you would recommend?

[fastacton]

I personally don't care for in tank pumps (I don't like to pull an otherwise good gas tank just for a pump). The only pump that has been completely reliable for me to the point that I'd recommend it is the Walbro GSL392 inline pump.

[Rally Smith]

I personally don't care for in tank pumps (I don't like to pull an otherwise good gas tank just for a pump). The only pump that has been completely reliable for me to the point that I'd recommend it is the Walbro GSL392 inline pump.

I think I would prefer an in tank pump, do to keeping the noise down. Any recommendations for in line pump?

[whatif3387]

I run a AC delco TPI pump in my 95 c1500 tbi truck. It was a direct swap for me it works great but it did over power the spring in the stock regulator I had to try out a few different springs. I believe my stock spring was just worn out after 230k miles though.

[Rally Smith]

Hey guys, I'm back. So a few weeks ago I got a new fuel pump that is rated at 30 psi. I am getting plenty of pressure now. I adjusted it to 16 psi and made changes in the tune to recognize the new pressure. I have data logged more and have the numbers pretty close for now. When I first start up and drive while in Open Loop it will go Rich while I am on the gas and come back when I back off of it. After into Closed Loop, I can give it some gas and it doesn't really go rich at all. I have adjusted the AE/TPS % and AE/MAP #'s too. With my laptop hooked up, I press on the gas a bit and see it is in AE for just a very short time, but when in C.L. it goes a bit lean.
When reading the XDF it says that the AE/TPS% is only active for a 10th of a second or so then the AE/MAP takes over for the next 2 seconds or so. When in the AE/MAP should the computer still show in AE?
With that being the case, do I just need to keep adding to those tables? If so, what problems am I going to have when it's in O.L.? I haven't check the pressure under load at the TBI yet but assume it's going to drop a little. Should the fuel pressure drop at all when the gas is increased? That is a bunch of questions again, but I very much appreciate your guys's help.

Thanks,
Rick

[PJG1173]

if your pump can flow enough fuel and the regulator is good then you shouldn't drop pressure. have you watched your monitors while stabbing the throttle? I use the monitor view to see how rich (or lean) it gets when I stab the throttle. the below image is where I did a 1700 rpm launch. you can see where it went to 10.5 AFR a couple milliseconds which made me decrease MAP AE to correct it. not saying my AE is perfect now but its a lot closer.