Need help with new installation.
New set-up on 1973 Chevy C20 truck, stock 454 with Turbo 400. I have the Street EFI 400 with in-line fuel pump, 50001 I think. As I'm driving I can hear the pump changing pitch, getting subtle, meaning quieter. Seconds later I can't apply any throttle, the engine will just idle. Key off, wait a minute, key on, wait for it and I hear the fuel pump revving up. Only then can I start the motor and drive away. BUT, I can only get to about 25 on the TPS, any more and the engine stumbles, won't rev.
Also having a hard time getting the engine to 170 for auto learn. I've read about the the senders but the stock gauges seems to back-up the EFI reading. Besides I just bought this, wouldn't FI Tech have given me a good sensor?
Thanks for any help.
Great question. We have been dealing with bad temp sensors for years now. Fitech is not listening. Simply replace with a delco unit. Most 80s and 90s GM vehicles used the same sensor. I pulled one out of an old motor and have been using it for 2 years now.
Until you reach 170 or above, it is useless to tune your system. Don't even try. You will need to start all over once sensor is replaced.
As for fuel pump, describe your entire fuel system. Are you running the on the Orange wire? How is your "Ground"? I have ideas, but need more information. Also get a fuel pressure gauge. $10 from Fitech. Simply drill and tap on of the fuel rail plugs.
Here's the whole story up til now. New installation using their in-line pump and filters. Stock fuel tank with home made return line in the filler neck. Possibility that the tank wasn't venting correctly (more on that later). I can get the truck up to temp now that the weather is nicer. Very predictable scenario: run up the road about 15 miles and the pump doesn't stop running but seems as though the pressure is gone. You can tell it's going to happen by the overall sound of the pump. Seconds later I'm at the side of the road trying to recycle the system (key off, wait for handheld to clear, key on, listen to the pump). Eventually the pump will "rev"up and you can hear the fuel flowing. Trucks starts and I can go another 15 miles before it happens again. I removed one end of a vent hose off the filler neck to eliminate any possibility that venting is an issue. No difference.
Called Tech and they asked about venting, heat, obstructions and the normal kinda stuff. In order to appease them I have removed the tank, plumbed all new lines (three outlets on this particular truck model) and moved the pump outside the frame rail away from heat. I will finish all that up this morning with a new relay in the system.
I will made a report this weekend on whether or not that fixes anything.
Those pumps are designed to be placed very close to the tank. Could this be the issue?
Given all the requirements for these pumps, ie: within 2-3 feet, lower than the tank and away from heat, I feel it is now in the best possible location for this specific vehicle. If this doesn't satisfy the Techs I may have to rework my tank for an in-tank model.
- You need to login to have access to uploads.
In tanks are my preferred route. Try an 87 fuel pickup assembly. These had in tank pumps. Low pressure but same pump dimension. If it won't fit your tank, then look into getting the whole 87 setup. Should bolt right up.
I have done this to an 86 with dual tanks. We used 87 assemblies, changed the hoses to high pressure and ran through the factory selector valve. I add a relay to the valve that would select the pump. Changed the switch to an 87, because it actually has a detent switch. It works flawlessly. My customer couldn't be happier...