I know there's a lot of "My truck died" threads, and i searched thru them, but there seem to be a lot of differences.
I was just driving along at 40mph, and it died. I'm getting a pull back to my house, but need to get it fixed over the weekend.
Here's a brake-down.
It's a 91 Bronco with a 302. It has about 90,000 miles.
It has lights and power.
It cranks good and strong.
I think the fuel pump is kicking on, but don't recall for sure.
I seem to remember the gas pedal coming up. That was wierd.
It fealt like someone just pulled the ignition coil wire off or something.
My 89 mustang did something similar when the TFI module went out on it. That's the first thing that came to mind.
But I saw another post about a 94, where the TFi was on the fenderwell. Where is it in my 91? On the distributor?
I'm just trying to do some pre-planning before jumping into it tonight.
Thanks!

 

check emergency fuel cut off switch.

 

the tfi on your 91 its still mounted to the dizzy.

 

OK... I don't think the fuel pump is kicking on when turning the switch on. I ussually can hear it. I looked behind both kick panels for the fuel cut-off, but didn't see it. I'm pretty sure it's either that, the fuel pump relay, or maybe a fuse for the fuel pump? Would the fuel pump itself just quit suddenly like that? Even if it's fuel related, though, I'd think it'd sputter a little as it used the last fuel in the lines. It just died all at once.
Thanks for the help so far guys.

 

it is by the pedals in a 91.

also under the hood in elec. distribution box you have a fuse and a relay for the fuel system.

 

Got this done today.
Confirmed that the fuel pump is not kicking on at all.
I found and checked the inertia switch, and it is not tripped. Could it have gone bad?
Is the "distribution box" the plastic thing behind the air box where the test plug is? It's got some plugs and one is marked fuel pump. I pulled the plug, and plugged it back in. Is this the relay? There's supposed to be a fusable link according to Chiltons manual, but it's nowhere nearby. I'd hate to unwrap all of the wiring to find it. Where is it at?

I ran codes. I have a 16? , 636, 114, 542.
The 542 is what I suspect is the main problem. Fuel pump secondary circtuit failure. PCM to ground.
16 is IDM signal not recieved? What's an IDM? I can't find reference to it anywhere.
636 TOT sensor out of range. Again, what is this?
114 ACT outside test limits. OK... It's a little cold here today.
Any other thoughts on these?
Thanks again. I got to get this fixed before Monday!

 

Now I've replaced the fuel pump relay, and the EEC relay... No change.
I'm waiting for the battery to recharge right now before trying anything else.
I'm going to probably end up taking it to a shop since all of my jack stands are being used already, and my jack itself has died. Plus the wife is no feeling good, and I'm out messing with this thing, and the two kids are driving her crazy!

 

I don't have the schematics for a 91 Bronco but looked at Autozones web-site.

Here's how the fuel pump circuit works. On the primary side of the fuel pump relay should be two wires.

Red wire should have 12 volts on it when the ignition key is in run position. the Light Blue wire is grounded by the Computer which will close the Fuel pump relay secondary contacts.

On the secondary side of the relay is a Yellow wire which has 12 volts on it at all times. It comes from a fusible link which I think originates at the Starter Solenoid Lug. The battery also has a cable directly attached to the same lug.

Assuming the inerta switch is closed.

When the Computer grounds the Light Blue wire, the relay closes. 12 volts from the Yellow wire passes thru the relay and out on the Dark Green/Yellow wire which feeds 12 volts to the fuel pump.

It sounds like you don't have a volt meter?

I can't tell from Autozones schematics if the Fusible link that feeds the fuel pump feeds other devices. If it doesn't and since you said the Computer has an error code for Secondary Fuel Pump circuit, I'd say the Fusible Link is blown or the Fuel pump relay is bad but since you replaced the relay, you've eliminated that.

If you look at the old fuel pump relay you could pry the cover off of it and manually push down on the little metal plate that closes on the relay when it is energized. If you do this with the ignition key in run, the fuel pump should run. If it doesn't you need to measure if you have 12 Volts on the Yellow wire. If you don't the fusible link is blown.
If you do have 12 volts on the Dark Green/Yellow wire and the fuel pump doesn't come on, the Fuel Pump is probably bad.

 

Electronics is not my strong suite, but I do have a multimeter.
I'll try these tests t omake sure it's the fuel pump. I just talked to a shop, and they said it'd be about $320 + the towing bill to get it there.
I'd do it myself, but it's raining, my garage is occiupied by two cars that can't move, plus my gas tank is almost full and I no way to salvage the fuel.

 

If you want, e-mail me your phone number and what time to call and i'll step you through the testing.

I'm located in Baltimore and on Eastern Standard time.

gmc862000 at yahoo.com

 

anyone check the ECM Fuse...had that happen on a GMC stepvan.....Even if fuse looks good try a new one.

 

I jumped the wires to the fue; pump and got nothing. Unless there is a break in the wiring, I'm sure it's a bad fuel pump.
The tow truck's coming this morning to take it and have a new fuel pump installed. Thanks for the help.
This should be a good thread for people searching. There's a lot of good info. here. Maybe I'll recap it all and submit it for a sticky, or FAQ?

 

Well, the shop replaced the pump, and went ahead and replaced the fuel level float so my gas gauge would work for the first time in 5 years. It runs again, and I'm going to have to get used to seeing my gauge actually working!
Thanks for all the help!

 

Good to hear you're back on the road again.