TUNED PORT INJECTION Q'S

1958 delivery

Well Known Member
Supporting Member 2
So I bought a 40 Ford pick up today. It has a 350 TPI. Went to the gas station, filled it up. Driving back home and it started making loud whirling noise, thought maybe fans but kind of too loud. Anyway pull in driveway and turned it off, all noises stopped, went to restart and would only crank, what the hell?
After thinking about it more, I didn't get the gas cap screwed on right. So I stuff the filler neck with a rag and it starts again, parked it in garage.
My question is will air coming in thru cap, since I never got it screwed on properly cause the fuel system to suck air? My thought is since it's a high pressure return type it must be sealed?? The loud noise must have been the fuel pump pumping air?? Please TPI experts confirm or deny, Thanks.
 

La Hot Rods

Well Seasoned Member
Supporting Member 15
Hard to imagine that a loose filler cap would cause that problem.
Wonder if the hose between the pump and outlet has gone soft.
 

1958 delivery

Well Known Member
Supporting Member 2
No Mike, you can leave the cap off and it will run just fine. I am wondering if your fuel pump is starting to die. That would explain the noise and the no start symptom.


You're sure? The cap and tank is not vented.
 

La Hot Rods

Well Seasoned Member
Supporting Member 15
Being frame mounted the pump needs the pressure in the tank to push fuel to the pump.
Sounds the fuel delivery system going to need some work. :scratch
 

MRHP

 
Supporting Member 1
How can the cap and tank not be vented??? As the fuel is pumped to the motor, you would pull the fuel tank into a vacuum. Not the way it works. You can leave the vehicle running and fill the fuel tank can’t you? Tank needs a vent somewhere, but that is not your problem.
 

1958 delivery

Well Known Member
Supporting Member 2
Aren't fuel systems that have a constant return non vented? Fuel injected car of today use a non vented system the return takes care of not going into a vacuum
 

1958 delivery

Well Known Member
Supporting Member 2
I guess it could be coincidental that it started after stuffing the rag in, but it seemed very strange to me. Before I stuffed the rag it cranked with absolutely no indication of firing, free cranking if you will. Stuffed rag and it started to ignite then started.

My fix for a TPI problem was going to be to install carburetion:wacko
 

MRHP

 
Supporting Member 1
The new systems vent through a pcm controlled vent valve and a charcoal canister. There is no need for any pressure in the fuel tank for the vehicle to run. There is also a purge solenoid and fuel tank pressure/vacuum sensor in the fuel tank to monitor for leaks when the evap system goes through its checks. Your fuel tank needs a vent somewhere, either at the tank, or at the cap.
 

1958 delivery

Well Known Member
Supporting Member 2
OK. I'll keep my fingers crossed that it was a fluke and doesn't occur again. The car has sat for years. The TPI is an Edelbrock, I don't think they even make them any more. Hopefully I don't have to replace with a carb set up. My immediate problem now is the gas cap has boogered threads (aluminum) It's an under bed aluminum tank and the fill pipe and cap are aluminum, might end up replacing that too.:doh
 

blkblk63ss

Well Seasoned Member
Supporting Member 5
Sounds like fuel pump was making the noise and would have stalled anyway if you drove much further. When you shut it down ,it would not run again when you tried to restart only after setting awhile and cooling down. Just my 2 cents.
 

1958 delivery

Well Known Member
Supporting Member 2
I can't think of anything else that could make a fan like noise other then the fuel pump, the existing fan doesn't make that loud of noise

I think maybe it went way rich, I did smell a slight gas order when I was cranking it. Let it sit 20 mins and started up, hopefully the pump doesn't act up again. I think these pumps are a few hundred dollars.
 

blkblk63ss

Well Seasoned Member
Supporting Member 5
Try a additive like marvel mystery oil. Fuel gets varnished setting a lot g time. It would lube pump. Be worth a try.also check fuel filter for blockage.
 
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