1988 Bronco II Fuel Issues?

[jaxwithanx]

I just purchased first Bronco II, sort of an impulse buy. I have always loved the body style and it was really straight with no rust and runs well. There are only two issues going on that I thought I should be able to fix fairly easily. That's where you guys come in, hopefully....

1. Fuel gage does not work at all, owner said it intermittently would, but I have only driven a handful of times and have not seen it move yet.

2. Runs well and smooth for first minute or so then idle slowly starts to decrease and it will sometimes shut entirely off, sometimes not. It never starts sputtering, but it is almost as if the fuel pressure cycles down for a short time and then picks back up. It does this while driving too. When accelerating and going through gears everything seems fine but once I coast or decelerate for a few seconds and press the gas again I get nothing, or if I do it is a very weak return. Definitely not proportional to the amount I'm down on the pedal. It never completely dies, just does not accelerate again until I drop down a gear or pump the clutch a few times and that seems to get it going again.

These issues scream fuel pump and filter to me but I'm not sure which fuel pump to attack or if this might be an injector or electrical issue. The fact the fuel gage doesn't work either seems like it might point to part of the issue as well....but I'm not an expert by an means.

Any help appreciated, thanks in advance!

BTW I will try pulling codes in the next couple of days. Also, I used search and found some similar cases but my problems seems pretty specific so I was hoping someone would be able to make a little better sense out of my situation.

 

[jaxwithanx]

BUMP

Any help...thoughts?

 

[Mike828]

Did you change the fuel filter?
Were there any codes?
Have you checked fuel pressure?

Mine would run fine one second then sputter and not rev up and usually die. It finally did it in my driveway and I got a fuel pressure gauge on it and watched it just slowly fall to nothing. My gauge also didn't work so I dropped the tank and found a mess. Wires hardly there, float gone. Got a whole sender/pump assembly and it did the trick.

 

[jaxwithanx]

Yeah my fuel pressure just plummets.

You talking about something like this? http://www.rockauto.com/catalog/moreinfo.php?pk=872370

Or this? http://www.rockauto.com/catalog/moreinfo.php?pk=1975322

In all honesty though, I guess I probably should just drop the tank and find out what all I need for myself. Any tips beside getting as much gas out as possible?

 

[Mike828]

I got the same but at Advance Auto. Put in a code and you can get it for like $60 then go pick it up.

Some people cut an access panel and don't drop the tank. I will the next time for sure.

Can you hear the high pressure pump run for 2 seconds when you turn the key to on?

 

[jaxwithanx]

I got the same but at Advance Auto. Put in a code and you can get it for like $60 then go pick it up.

Some people cut an access panel and don't drop the tank. I will the next time for sure.

Can you hear the high pressure pump run for 2 seconds when you turn the key to on?

Yeah I can hear the HP pump when I turn on accessories. The one at Advance Auto doesn't look like it has a pump (http://shop.advanceautoparts.com/we...ium_18320672-P_2159_R|GRPFUE2AMS_624630687___) and the same Spectra unit on rockauto.com does come with a pump for $73. Guess I won't know for sure if I need the actual pump until I'm down in it but I might as well for $13 more.

 

[Mike828]

Here's an Airtex sender and pump.

http://shop.advanceautoparts.com/we...irtex_3150747-P_52_R|GRPFUE2AMS_1539445101___

If you put in the code BIG35 it's $62.

I would look in the tank and see whats going on.

 

[Earl43P]

Disconnect the high pressure pump electrical connector.
Disconnect fuel ine into high pressure pump.
Turn key to run. Does fuel flow? That tests the in tank lift pump.

Reconnect input to HP fuel pump and its electrical connector.
Disconnect output line. Turn key to Run.
Does high pressure fuel flow? Probably yes, otherwise it wouldn't start and run.

In short, I think your in tank lift pump is inop, starving the HP pump resulting in your symptoms.

 

[jaxwithanx]

Disconnect the high pressure pump electrical connector.
Disconnect fuel ine into high pressure pump.
Turn key to run. Does fuel flow? That tests the in tank lift pump.

Reconnect input to HP fuel pump and its electrical connector.
Disconnect output line. Turn key to Run.
Does high pressure fuel flow? Probably yes, otherwise it wouldn't start and run.

In short, I think your in tank lift pump is inop, starving the HP pump resulting in your symptoms.

Thanks for all the help guys. I bought an in-tank pump and plan to start work tomorrow. Anyone know of a good link for a tutorial on where and how to cut the cargo area sheet metal to access the tank?

This is the best I've found for location...

http://www.explorerforum.com/forums/showthread.php?t=242331

 

[jaxwithanx]

Replaced in-tank pump today and unfortunately this did not help. Oddest thing, it's like intermittently at lower RPM's it just starts losing power occasionally. I did however notice something odd today though I hadn't before. The high-pressure pump on the rail never stops pumping when I've got the accessories on. It's like it never builds any pressure....just a constant gurlging/electric sound but it never quits. Also the engine will stay running and idling but every couple of minutes it sounds like it is about to die and all of a sudden after a few seconds something goes ahead and clicks or switches (not audible) and the engine slowly builds back to correct RPM.

At first I though, vacuum-issue because the way it will correct itself when I downshift into a higher RPM and then continue on. But my brakes are fine and after watching the way it acts while it is idling I have to think maybe a solenoid or switch is the cause.

Any suggestions...ideas?