fuel control solenoid, emission control relay (1 Viewer)

[a bruiser runsthruit]

hey all been getting the most useful info on this site for 3 years now and have figured it all out cuz of y'all. so first I'd like to thank everyone that takes time to post solutions on here.THANX!!
so here's my deal that I can't figure out on my 84 60. my fuel cut solenoid isn't getting power. I hotwired it off the battery and it clicks, but it doesn't get power when plugged at the harness, even when I ground the neg. wire. I ordered a used emission control relay...and nothing. the truck idles hella rough if at all and I usually have to pull the choke out when I come to lights or stop signs. my tach goes out intermittently as well.not sure if related prob or not. any and all suggestion will be greatly appreciated. ih8 mud baby!

 

[Slow Left]

Pull the 10A "Engine" fuse from the fuse box in the cabin of the vehicle (to the left of the steering wheel).

Is the fuse good?

You can visually inspect it or even test for resistance or conductivity with a multimeter.

 

[a bruiser runsthruit]

the fuse was burnt jus now, but it wasn't b4 cuz Ichecked them afew times and it is replaced....no difference.

 

[Slow Left]

OK. There is an ignition control relay before (on the battery side) of that fuse.

Here is where that relay is:

 

[Slow Left]

Another image of relay block:

 

[Slow Left]

Wait one...

I'm trying to find an electrical test for the ignition relay so you can pull it and test it...

 

[Slow Left]

Here is the circuit for the Fuel Cut Solenoid.

See if you can find a test to test whether or not that ignition relay is working correctly. Do you have a Factory Service Manual?

I looked in the Chassis and Body Electrical (where I found the pictures showing where it is located) but ironically, they didn't provide the test procedure for the ignition relay. I'll have to double check my hard copy when I get a chance.

But looking at the circuit, it could be the ignition relay, Emissions control computer or even the alternator regulator.

Also check that fusible link, 'W'

 

[Slow Left]

Both the Emissions Control Computer and the Tachometer get their signal from the coil on the same line:

 

[Slow Left]

Test the Coil (as per test procedure outline in the 2F Engine FSM). If the coil is bad, both the emissions control computer and tach might be getting a shoddy signal.

 

[Slow Left]

Also:

1) pull the Emission Control Computer and measure resistance between pin #12 (Fuel Cut Solenoid) and pin #7 (ground). What is the resistance value?
2) find/follow test procedures in the FSM to test: the ignition relay and the alternator regulator

 

[Slow Left]

I can't find a test procedure to test whether the Ignition Relay is function correctly.

Is there a part number stamped on the Ignition Relay?
Does another relay share the same part number as the one stamped on the Ignition Relay?
If so, is there a test procedure in the FSM for that relay?
If yes, run the test procedure and see if the Ignition Relay checks out as operational.

Or, you mentioned that you had ordered a new, used Ignition Relay.
Develop your own test, based on the test procedures on other Relays in the FSM, and see if the results differ between your current Ignition Relay and your new, used Ignition Relay.

 

[Slow Left]

See Chapter 9 in the "2F Engine Repair Manual" FSM for testing the charging system.

Page 9-39 has a test procedure for the Alternator Regulator.

 

[Spike Strip]

Disconnect the wire at the tach and ground the NEG white wire at the solenoid to the carb body and see what happens.

 

[a bruiser runsthruit]

I replaced my 10a fuses at ac and engine. results are fuel cut solenoid clicks now and carb fan running again and tach good. still can't keep running w/o choke. ruins rough will not idle

 

[a bruiser runsthruit]

I replaced my 10a fuses at ac and engine. results are fuel cut solenoid clicks now and carb fan running again and tach good. still can't keep running w/o choke. ruins rough will not idle

 

[Slow Left]

I replaced my 10a fuses at ac and engine. results are fuel cut solenoid clicks now and carb fan running again and tach good. still can't keep running w/o choke. ruins rough will not idle

OK, so you replaced a blown 'Engine' fuse and now the fuel cut solenoid is clicking and the tach is working again. But the original symptoms still exist.

Then if there is still a problem with the circuit outlined above, you might want to the the diagnostic tests on the components in that circuit (coil, Emission's computer, and ignition relay). Note that if you do the mod that Spike describes, then you are bypassing the Emissions Computer (the ignition relay is grounded through the Emissions computer - see wiring diagram and post#10 to test the circuit of that ground in the computer) and removing the tach signal from the circuit.

If other components in the circuit all test out OK, then maybe you can assume that the symptom is being caused by an additional problem.

You could test for misfire in each cylinder by removing, one at a time, the ignition wire at the spark plug with the engine idling and listening for a change in idle. If there is a piston(s) that registers no change in idle sound, then there is an issue.
You could then run compression tests on the cylinders, too.

If that all checks out OK, I would begin to assume that there is a vac leak (a big one at that, if it can't hold an idle).

 

[a bruiser runsthruit]

I checked for vacuum leaks as one of the first things with carb cleaner while it was running.....no changes. I had this problem on my last 60 , but it was the ground on the fcs. I'm stumped. when she runs, she sounds great , in time, just nice. sorry my replies are so scattered.in the process of moving. and thanx guys for taking the time to help.

 

[Pin_Head]

Check for power on both sides of the ignition fuse with the key on with a test light probe. No power, then the ignition relay is probably bad. If there is power on only one side of the fuse, the fuse is bad or the fuse block has a bad connetion.

 

[a bruiser runsthruit]

thanx again guys.....I took it into town a couple weeks ago and now it runs fine. idle and all . if I have future problems I'll check into this pinhead. I think something may have been lodged in the carb or something. anyway, peace and chikken grease!

 

[Slow Left]

So any idea what was wrong with it? From the information you provide it sounds as if the fuse was the problem, and then once that was replaced it began operating normally again.