EFI help
Thread Starter
|
New User
Joined: Oct 2007
Posts: 5
Likes: 0
EFI help
i scored a smoking deal on an 86 with a 302, 6" kit and 36" TSL's but im having a problem getting it to fire. the fuel pumps are both working and wired to a toggle switch. i have great spark and it set pretty much where it needs to be to atleast start. i think i have in narrowed down to the injectors are not firing. i have fuel pressure all the way to the schader valve in the fuel rail but when i pulled a plug to check they are not wet and i can get it to fire on starting fluid. is there anyone out there that can offer me any help or ideas before get really pissed and put on a holley. i coudnt pass it up for $500 but i am not very familiar with the Ford EFI. thanks.
Posting Guru
Joined: Feb 2006
Posts: 1,448
Likes: 1
Why are the pumps wired to a toggle switch? If they will not start/run on their own, you have a problem elsewhere. The computer must see ignition pulses in order for the pumps to start.
It sounds as if there was a problem no one could fix, and they patched it with the switches. jd
It sounds as if there was a problem no one could fix, and they patched it with the switches. jd
Posting Guru
Joined: Feb 2006
Posts: 1,448
Likes: 1
Heres how it works.
Ignition on - EEC power relay closes supplying power to the pump relay and sensors.
Pin 22 of of the computer momentarily grounds closing the pump relay for a couple seconds priming the system, then it removes the ground waiting for ignition pulses from the distributor.
Starter engages spinning the engine supplying ignition pulses to the computer, grounding pin 22 once more supplying a steady supply of fuel to the injectors.
Pin 58 of the computer pulse grounds the injectors supplying fuel to the engine. The injectors are supplied by 12vdc. At ignition on with the engine not running/turning over, you should have 12vdc on both wires of the injectors.
I use a test light, and spin the engine over. If the injectors are working, you can see the light slightly dim as the injectors fire. You can also use what is called a "noid" light. This will tell you if the injectors are working. These are kind of expensive as you have to buy them in a set. Maybe you local auto parts have loaners.
However, the first thing I would do is get rid of the switches, and get the system working as designed. This kind of "rigging" will sometimes confuse the computer causing other problems. jd
Ignition on - EEC power relay closes supplying power to the pump relay and sensors.
Pin 22 of of the computer momentarily grounds closing the pump relay for a couple seconds priming the system, then it removes the ground waiting for ignition pulses from the distributor.
Starter engages spinning the engine supplying ignition pulses to the computer, grounding pin 22 once more supplying a steady supply of fuel to the injectors.
Pin 58 of the computer pulse grounds the injectors supplying fuel to the engine. The injectors are supplied by 12vdc. At ignition on with the engine not running/turning over, you should have 12vdc on both wires of the injectors.
I use a test light, and spin the engine over. If the injectors are working, you can see the light slightly dim as the injectors fire. You can also use what is called a "noid" light. This will tell you if the injectors are working. These are kind of expensive as you have to buy them in a set. Maybe you local auto parts have loaners.
However, the first thing I would do is get rid of the switches, and get the system working as designed. This kind of "rigging" will sometimes confuse the computer causing other problems. jd
Last edited by jimdandy; Oct 21, 2007 at 03:59 PM.
Junior User
Joined: Dec 2006
Posts: 50
Likes: 0
I've got same problem!!!!
81TREKKER, I'm having the same problem with my 87 f350 351w, I switched from carb to efi motor will fire on starter fluid, but fuel pump will not run (i jumped to 12v bat to get it running) and fuel injectors will not fire. I'm going to work on the problem during holidays. Let me know if you come up with anything.
Could someone tell me where the pwr relay is?
philbax
Could someone tell me where the pwr relay is?
philbax
Moderator
Joined: Dec 2001
Posts: 22,436
Likes: 17
From: Louisville,Ky.
ECM relay should be near the core support on the passenger side I believe on the 87 model. If not there, it should be under a cover near the master cylinder. It will say EEC and is grey. The Fuel pump relay is green.
Trending Topics
Fleet Owner
Joined: Aug 2005
Posts: 23,667
Likes: 301
From: Easton,Ks
Originally Posted by philbax
81TREKKER, I'm having the same problem with my 87 f350 351w, I switched from carb to efi motor will fire on starter fluid, but fuel pump will not run (i jumped to 12v bat to get it running) and fuel injectors will not fire. I'm going to work on the problem during holidays. Let me know if you come up with anything.
Could someone tell me where the pwr relay is?
philbax
Could someone tell me where the pwr relay is?
philbax
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Junior User
Joined: Dec 2006
Posts: 50
Likes: 0
can't find eec relay
My replacement efi motor came from a 89 bronco, I've replaced all cab wiring and engine compartment wiring. The only relays I can find are on driver side by air filter, they are not labled one is green the other one is brown. I have nothing labled eec relay.I have one conn. labeled eec test
Thanks
Philbax
Thanks
Philbax
Fleet Owner
Joined: Aug 2005
Posts: 23,667
Likes: 301
From: Easton,Ks
The brown one is the ECU (EEC/PCM) Power relay and the green one is the fuel pump relay.
The EEC test plug.
There should also be a one-wire plug near this one that runs (starts) the EEC system test (for pulling codes).
/
The EEC test plug.
There should also be a one-wire plug near this one that runs (starts) the EEC system test (for pulling codes).
/
Last edited by subford; Nov 21, 2007 at 04:42 PM.
Junior User
Joined: Dec 2006
Posts: 50
Likes: 0
Hey thanks, are there any other relays that supply voltage to the fuel system? I was going thru posts and came across somthing about a bk/grn wire in round connector located by batt should be connected to batt ground, this wire provides ground to the eec pin 40 and 60 I do remember this connector during swap just did'nt know where to con it.
Fleet Owner
Joined: Aug 2005
Posts: 23,667
Likes: 301
From: Easton,Ks
It goes to Negative Post of the battery. The Fuel Pump Relay activation coil is grounded through the computer and the computer is ground through this wire to the Negative post of the battery by way of pin 40 & 60.
/
/
Junior User
Joined: Dec 2006
Posts: 50
Likes: 0
Thanks for the help! I really appreciate all the helpful tips that are on this site and for the experienced people willing to help out. I think that wire not being grounded is my problem (or one of my problems) I'll check first thing in the morning. Have a great nite and holiday