walter34payton2002

Hey guys. Ok I traced my problem finally after almost half a year. Please follow very closely I am need of help here for the finale. The car will not start UNLESS when I turn the key to position 2 I get "2 CLICKS" from the engine bay and the fuel pump stops priming. Now let me explain.......

2 clicks- I know one of the "click" noises I hear when key is in position 2 and I listen to the engine is the fuel pump relay. What is the second??? It may come from behind the dash somewhere. My fuel pump sometimes won't stop priming. If it keeps priming it won't start no matter what. If I get the 2 clicks- one of which is the relay- and the pump stops, it will fire right up like clockwork.

Now....Before you say fuel relay, NEGATIVE on that. 2 new ones and I bought one yesterday. I am thinking somewhere in the ignition cylinder or ignition switch maybe??? That is what actuates the relays and stuff, right? I need to play with the key position 1 position 2 constantly to wait for the 2 clicks. When I get them, bang I can fire her up. If the pump just continues to run, no go no matter what I do it won't start.

This is a 1985 f150 302 engine fuel injected.

klricks

One of the clicks, probably the 1st click, could be the EEC power relay. Shown here:
http://i608.photobucket.com/albums/t...FIfuel-sel.gif

Note that there is not really a priming action. If there is it most likely has more to do with getting the EFI fuel pressure up, but that only takes half a second.

When you turn the ignition on, the EEC turns on the pump relay which turns on the HP pump and tank pumps. If the engine is started right away, then the the fuel relay and pumps remain on.

If the engine does not start in 3 to 5 seconds then the EEC turns off the pumps to conserve battery power and to keep a tank pump from burning out if you had the fuel tank selector set to an empty tank.

Looking like the EEC or connections to it.

Good old Bill

Agree with klricks, the PCM controls the duration of the pump during the key on mode. It then goes on to bigger and better events, like ignition.

walter34payton2002

Excellent. One problem, however. This truck contains one relay and one relay only. Not what I was expecting either. Unless.....the location of the EEC relay is in a different location that I cannot find, there is only the fuel pump relay sitting by itself in the upper right corner of the engine bay (facing engine). Interestingly, the plastic part that holds the relay has 2 slots in it, but only one relay. Any help as to location.

1985 f150 FI 302

walter34payton2002

I am searching for the relay. KL- thanks for the diagram. I am going to take some pics if I can't find it or if its not there. I wonder if previous owner bypassed? But then 1. why and 2. how?

walter34payton2002

Found what looks to be it, but was under dash right next to PCM. When I pull it fuel pumps stop. I went to autozone and asked for eec relay. ALl they had was ignition relay. Got it and same thing. That is the problem though and as long as that relay don't click the fuel pump relay off, it won't start. The autozone part I got is 913182. That number is off the relay. I am thinking it is the wrong relay???

walter34payton2002

Today I also changed the ignition switch and cylinder. I changed the aforementioned relay. Same result. I turned key to position 2 and ran to the engine bay. I waited for the random timing of the clicks. There are 2 clicks that come from the fuel pump relay and one slight click that comes from the IAC. The truck will turn over and over and over but won't start until you sit and wait for the clicks of the fuel pump relay with key in position 2. When you get that, she fires right up. I am thinking this has to be the computer.

Questions: What actuates the clicking of the fuel pump relay? What causes it to "click?" If it is the ignition relay, that was just replaced.

What happens the pumps just keep running, which to me in itself is not a problem. If too much fuel was the problem, then the truck should start when I manually pull the relay or start it right away or whatever method I use to control the fuel. It will only start, however, when the relay clicks by computer control. You can imagine the frustration. I wouldn't care so much if I had to wait for the relay to click for 5 seconds or so, but this is random. It could take 5 seconds, 5 minutes, or not at all and I have to turn key to position 1 then 2.

klricks

The EEC relay is probably OK. If it did not work then the fuel pump would never come on at all. The EEC relay supplies power directly to the fuel pump relay. See wiring diagram.

I was thinking that the problem is the EEC computer itself. Since your pumps run on after the programmed 5 second timeout and the engine does not start reliably etc. (These are functions that are controlled by the EEC).

There could be other issued however that might be causing the EEC to act funny such as a short circuit somewhere or bad connection at the EEC etc so replacing the EEC is not a 100% guarantee to fix the problem(s).

walter34payton2002

KL thanks man. Stay with me here bud. I think the wiring diagram is not correct for 1985. The wires coming off the relay under the dash near the ecu (EEC I believe it to be) are different than that on the diagram.

KL I really believe a new harness and ECU would do it, but my pocketbook won't. I think I may go for an ECU.

KL....Here is a strange question, but follow me here. Why in the world would I hear the IAC actuate right after the fuel pump relay clicks off??? Also, when the fuel relay clicks off it clicks twice. Only and only when it clicks will the truck start.

It goes something like this.....Turn key to pos 2. Wait for 2 clicks of fuel relay then you hear the IAC actuate (clicks). What the hell????

klricks

The first diagram I posted is a simplified version of only the part that runs the fuel relay.
Note that is is possible the there were some changes between your '85 and the '86 version shown in these diagrams.

Here are the real diagrams 3 pages:
http://i608.photobucket.com/albums/t.../8650EECp1.jpg
http://i608.photobucket.com/albums/t.../8650EECp2.jpg
http://i608.photobucket.com/albums/t.../8650EECp3.jpg

And the real fuel relay / tank select digram:
http://i608.photobucket.com/albums/t...0/duelfuel.jpg

The fuel pump relay will click first time (ON) when the key is turned to run then if not started, it will time out after 3 sec and click a second time (OFF). THEN if you turn the key to start, the fuel relay will click 3rd time back (ON) again but you probably won't hear that over the other engine noise.

I have no ideal of the sequence of other relays and solenoids and there are many - EGR etc.

You said before that the fuel pumps are sometimes running on longer than the 3 second timeout and the engine won't start. That led me to believe that the EEC might be bad as that is what controls the running of the fuel pumps + everything else.
There could be other problems such as grounding or other wiring problems.