88 Bronco 11 Stalls/idles weird

[Smellslike1974]

Hello,hopefully you guys can help me out with this! This has been an ongoing problem and has sort of been in stages.

The problem that I first started having was this: My bronco would start,idle,warm up normally. Then after driving for a while, if I stopped and turned it off. When I go to start it back up,it doesn't want to idle and if I don't give it gas it will just shut down. I end up having to keep it at 1,000 rpm to shift or it will cut,this means riding the brake which I hate doing.

I tried fixing the problem on my own thinking it was ignition:
-New Spark Plugs
-New Spark plug wires
-New distributor rotor
-New Distributor Cap

After that the stalling problem still existed but it ran way better(it needed all of that!) Eventually after a while though the bronco just stopped starting completely. On my way home one day it bogged and died, wouldnt start back up...

Then I leaned towards it being a fuel issue:
-New fuel pump/sending unit in tank
-New fuel filter(one closest to engine)

This is where I am stumped guys... The bronco will start/run and drive but I am still having the issue of it stalling when I go to start it again after the initial start and drive. Obviously everything I have put into it,it definetly needed but I am confused on what it could possibly be. Sometimes,and when i say sometimes i mean rarely it will start and idle by itself when starting after driving it,but when it idles it fluctuates high and low almost tripping on itself like its about to stall but comes back to normal.

I have read from multiple sources that the bronco has 2 fuel pumps and two fuel filters. An internal pump which is in the tank and an external which is mounted on the chassie. I have also read that the internal pump pumps fuel to a filter then to the engine,and also theres a second line connected to the external pump which connects to the second filter then to the engine. Can anyone clarify this? Maybe a diagram? Whether or not its the problem I would like to put on the second filter and see if the external pump is working correctly. Underneath the driveside is the second fuel filter hugged by a removable frame peice. Maybe 2 feet towards the back of the truck is a vertical looks canister Is this the external fuel pump?If not does this get clogged,Is it even important!?

I thought maybe it was a vacumn leak also but cannot find whats leaking if so.

Any questions please ask!

 

[wildbill23c]

Not really exactly sure, but that canister you see is not a fuel pump, its just an empty reservoir for fuel, there's no filter or pump in it.

Definitely check everything for fuel leaks, vacuum leaks, etc. Sounds like you aren't getting the proper amount of fuel at times. You may try and just bypass that fuel reservoir temporarily by splicing the hoses together and see if your problem goes away, could be that the reservoir is partially plugged somewhere causing your intermittent issues.

 

[Smellslike1974]

Thankyou for your reply.

I removed the external fuel pump,it works fine.

When removing the reservoir hose gas kept pouring out. Apparently theres some sort of syhponing at work.

What exactly is this fuel reservoir for? What are the downfalls of just bypassing it completely?

Also while i was checking for vacuum leaks and having the motor running for maybe 10 minutes it just shut off. Went to start it again and it wouldn't start. Took the intake hose off,sprayed ether and it fired right up. Could the problem be the fuel control thing that the fuel lines go into?

 

[wildbill23c]

I believe that fuel reservoir was to hold extra fuel for fast acceleration until the fuel pumps could catch up, kind of to keep the engine from starving for fuel if you take off really fast as the fuel pumps take a couple seconds to catch up to the sudden load.

I think you can just bypass that reservoir, if you disconnect the lines, yes fuel will pour out LOL. Just splice the lines together and try it out, newer high pressure fuel pumps will solve that reservoir problem anyways.

 

[Smellslike1974]

Obviously fuel will pour,yes...but it continually poured out as if the pump was on.

Guess ill have to quickly make a temp line.haha

 

[wildbill23c]

Try taking off your gas cap, the tank may have been pressurized still LOL. As for bypassing that canister, just get some inline hose splices and hose clamps and start splicing LOL. I think in the 86 models that canister actually had a filter in it, Autozone actually sells that whole canister still I believe but if I remember right someone else on here said they got rid of theirs because they were having similar problems as you are.

 

[Daniel T.]

i got rid of that canister and never had any problems again (it leaks no matter what you do) the only thing thats probably gonna be hard is not breaking the lines while taking that thing out,so you got to be careful.i got pictures of this if you want them.