AFI check

[Orange74]

Ok, here it goes I got an afi system installed with a dui that has been modified with esc on a stock 345 with 727. Back in I went out on a wheeling trip and shredded two tires so the truck sat for about four months until I could get show new shoes for her. I went out last weekend and the truck was running hot most of the trip (210+). We thought this was because she smelled like she was lean and this also seemed like because the fuel pressure would drop to about 7-8 psi, after the truck had been running for about 30 mins. When we would stop for about 10-15 minutes to let the truck cool the fuel pressure would come back up to 12.5-13 psi.

Over the past week I replaced the fuel pump thinking that it was the cause of the fuel pressure and why the truck was running lean. After replacing the fuel pump she was still exhibiting the same symptoms. I disassembled the fuel pressure regulator to check for anything out of the ordinary never the less I found nothing. After reassembly the pressure was at about 22 psi so I adjusted it down as low as I could but it only came down to 18 psi. The fuel pressure is stable but the truck is still running hot after driving when I come to a stop and idle its not as bad but I wasn't on a trail run.

I'm not to sure my issue is fuel related but frankly I don't yet know enough about FI to rule it out. I logged a run and saved the blm table in hopes that someone that does can. Also the cts seems to be about 15* off I think this is because it is installed where the vacuum temp switch used to be.

 

[Bill USN-1]

Your overheating has nothing to do with the efi.

Right now you are pretty Rich not lean.
Something else to keep in mind is that even if the fuel was lean the system is designed to automatically adjust so the air fuel ratio maintains 14.7:1.

So right now you have messed up something in the regulator or in the return line and it is causing the pressure to be high.
So take a reading on both lines.
If the return has pressure then you have a restriction and it needs fixed. If it's fine then the regulator needs fixed.

It sounds like you May have a nonvented fuel cap that is causing a vacuum as the fuel is used.

You also have the min idle screw to far in. The iac counts are at 0. So back it out about 1/2 a turn and adjust the tps back to 0% or .5volts.

You should ask questions here or at afi since it's their kit instead of your buddies. It May have saved you a lot of money on parts that weren't needed.

I'm heading to a show in canada so I won't be back till Sunday.

 

[Orange74]

Bill sorry it took me so long to get back work has been taking up a lot of my time.

You were right the overheating was not related to the afi I got the problem fixed by replacing the fan clutch with a new fixed blade fan.

I had originally checked the regulator after speaking with one of the guys at ihon.

I followed your steps from the sticky and set the idle, iac, and tps.

The fuel cap is vented.

The big problem is that I cant trust any of the pressure readings I had taken off my pressure gauge because this morning when I went to move the gauge to the return line the gauge was showing 10 psi when it was disconnected. I will have to run to hf and get a new one.

As for my buddies they didn't cost me any money as the pump I put in was a spare I keep in the truck. Before I did swap the pump I had spoke on the phone with ihon who agreed that if my fuel pressure is low and I have a pump handy to give it a try. I do check here if I have any questions and can normal find the answer in post for someone else dealing with the same or similar issue.

Thanks for the help.