New problems

[creekrat]

Sorry for the laundry list of PIDs that are in this log but i thought it might have been transmission related and wanted to get the big picture but after watching the fuel trims i believe this is fuel pump related. Started a couple days ago and was intermittent but it lugs down when stepping on the skinny pedal. After looking at this log you can see that the LTFT goes to 25% at partial throttle when trying to accelerate. I can ease it up to the higher RPMs and it runs fine but i think the pump may not be keeping up with the volume needed when accelerating fairly aggressively. It does seem to be more pronounced when the truck is warm but the pump would be constantly running then too and warm up. I am going to mess with the PE tables a little and see if that magnifies the issue but will also be getting a FP gauge to check for sure


wtf.efi

[Jetmech442]

While you're looking at gages to get, I'd recommend an extension hose so you can tape it to the windshield, So you can see it doing it under load.

It may be the FPR well. I went through 3 Corvette regulator/filter combos before I switched to an AEM regulator. (pressure is rock steady now)

I also bought an electric pressure sensor off eBay and 0 to 80 psi. I wired it into the egr on on the ecm just like the tutorial. It worked really well and was only like 20 bucks. The first one broke after 2 months and they sent me another one free. This one's been good for at least five morths now.

[creekrat]

Well this engine has had the harness reworked and it is a return style fuel rail. Have the vendor issuing a refund for the pump already. For the gauge i am going to run it permanently and have it mounted in the cab

[joecar]

So you did find a problem with fuel pump...?

[creekrat]

I do believe so. I used an airtex pump before i saw the reviews about them getting warm and losing efficiency. Hooked up a test gauge to the schroeder valve and at idle the rail has about 48-49 psi. When i remove the vacuum reference from the regulator no fuel comes out of the regulator and the pressure goes to right at 60 psi. When making it bog by getting on the throttle my pressure was dropping to as low as 15 psi and staying there till it slowly pulled itself out of the event it was in or i lifted some to curb the volume of fuel needed. I already have a new walbro headed my way and should be here monday. I'm thinking that the pump is getting warm and although it can slowly keep up with the pressure, when a sudden surge of fuel is needed it cannot keep the pressure up at the required volume

[joecar]

( so at idle you have about 22-24 inHg vacuum (11-12 psi) vacuum...? )

That pump/regulator is pretty bad if it drops to 15 psi.