1986 Bronco II EB 4wd 2.9 gas - warmed up dies no run for 20+ minutes

[Motech]

I guess that video i posted of crank and no start issue is no help?

Did not watch it. I saw your empty Check Engine light socket, but no mention of installing a bulb there to even run the test.

I watched it now though and cannot tell by the bright and blurry lights what's what.

 

[Motech]

With all your diagnostic testing and parts you've replaced, I think it's time you invest in some basic tools to make your life simpler.

Spark tester by Lysle, awesome tool maker:



$13.00 on Amazon, Clicky here



Now I don't know about this BETOOLL company, but for $34.00, it's a comprehensive kit that gets 4.6 stars after over 3100 ratings!



Clicky here

 

[johnnyreb]

Thanks Motech. After so long the connectors do get corruded and cause alot of problems. I,m gonna see about get me some of them connectors. On my 78 I went and replaced and added more ground wires with battery ground wires started from the motor and worked all the way to the tail light. What a person has to look at good are these parts . That are made in China and they look like American part-counterfit. Their light bulbs will have a silver tip--where American tips are yellow brass. Also check the fillment--even new.They can be bad from the store. Its why noy I get dependable part off of a old vehicle--better and cheaper.

 

[johnnyreb]

Thanks Motech. After so long the connectors do get corruded and cause alot of problems. I,m gonna see about get me some of them connectors. On my 78 I went and replaced and added more ground wires with battery ground wires started from the motor and worked all the way to the tail light. What a person has to look at good are these parts . That are made in China and they look like American part-counterfit. Their light bulbs will have a silver tip--where American tips are yellow brass. Also check the fillment--even new.They can be bad from the store. Its why noy I get dependable part off of a old vehicle--better and cheaper.

On your spark plug tester. They are good. I got mine at Harbor Freight. I used to take a ***** driver and put it in the plug wire and ground MYSELF. I was used to it. Then at the VA one day. The dr chewed me out. She said all it takes is a 1/4 to shorten your heart out. I told her I used to stick knives in electric outs to hear them pop and mom would whip me good,but it didn,t do me any good. But I think it saved my live. I got int some high voltage wires--that took the power into town. That felt good. It was barely raining. Yeah. I been pretty lucky in life.

 

[Tpremru]

Did not watch it. I saw your empty Check Engine light socket, but no mention of installing a bulb there to even run the test.

I watched it now though and cannot tell by the bright and blurry lights what's what.

The top right in the arning lamp area = Parking Brake
Top left in the round tach area = Oil Pressure
Bottom left in the round tach area = Battery

 

[Tpremru]

With all your diagnostic testing and parts you've replaced, I think it's time you invest in some basic tools to make your life simpler.

Spark tester by Lysle, awesome tool maker:

View attachment 30791 View attachment 30792

$13.00 on Amazon, Clicky here



Now I don't know about this BETOOLL company, but for $34.00, it's a comprehensive kit that gets 4.6 stars after over 3100 ratings!

View attachment 30793

Clicky here

The classic auto 1 man shop that i am now working with...i'm sure he has these, though it's still possible i may have to get these myself and learn...still thinking about this! thanks

 

[Tpremru]

Almost.

Check Engine lights were not required to pass a California smog check inspection on most light trucks until 1990, but most every domestic EFI (and many carbureted) light trucks had them.

As a computer progammer and lifelong musician i know i can't trust the internet but as it may here is one example of CEL....https://www.therangerstation.com/forums/index.php?threads/did-the-1984-bronco-2-have-a-check-engine-light.190590/

 

[Tpremru]

This can be misleading as it is simply untrue. All TPS--Ford and everyone else--are installed with some preload so they do not create a closed-throttle dead zone. To believe otherwise will spin a man in diagnostic circles.



Don't spin yourself into diagnostic circles.



Indeed, at connector # C161 between inertia switch and fuel pumps, which Ford sayus is located at the LH Fender Apron.


View attachment 30790



There is a reason these plugs are obsolete, and no reason to retain their originality. Setting yourself up with new connectors is an excellent upgrade, and an experienced electrical tech should be able to upgrade yours to infallible Weather Pack connectors for the price of a nice dinner for two.


View attachment 30786 View attachment 30787

View attachment 30788 View attachment 30789

Thank i think i will then not worry about the TPS for now.

I did purchase one of those connector kits but it could not handle the varying wire guages expecially the larger FP wire. I was looking on purchasing new custom connectors even from that Chicago company but they are 60+ $'s per connector, that's my conservative remembering lol.

here is another link i remember visting 2 years ago of Ford approved plugs...i don't think i will worry about these just yet until the issue is solved! https://www.fordservicecontent.com/pubs/content/connectors/images/connectorcatalog.pdf

Thanks so much for the wiring diagram! That looks different than the one i dwnlded from the Corral? More confusing is it looks like my single wire from fuel relay maybe yellow/black and split off to maybe pink/black which makes sense as i can see that color wire at the fuel send unit. But it also splits off to a larger guage looking like Red/Black. Then the Haynes manual i can not find wiring past the Inertia Switch.

 

[Tpremru]

Did not watch it. I saw your empty Check Engine light socket, but no mention of installing a bulb there to even run the test.

I watched it now though and cannot tell by the bright and blurry lights what's what.

After reading more about the CEL it doesn't sound like putting a bulb in the socket will do anything....but i am bound to try anyway, not sure when i will have that time though.

Top right light in the warning lamp section = Parking Brake
Top left light in the round tach section = Oil Pressure
Bottom left light in the round tach section = Battery

 

[Tpremru]

So...today i proved without doubt that the Lpump works. By disconnecting the 1 into 2 splice and trying each of the 2 wires independently with key on prime up, i recorded both Lpump and Hpump. So tomorrow at this moment i plan on going to Harbor Freight and p/u the spark tester and maybe even add the CEL bulb. Twice i already know that when it begins to die out fuel pressure goes from 40ish to 10ish or less. So spark tester will be interesting.

One question now is "Why does it seem to run fine with Hpump only?". I ran it for 10 minutes no issue without Lpump connected. Mechanics have told me it can not run without either! I did not drive it but goosed it from idle several times and did not hear any difference.

 

[goodO1boydws]

Better, yes, but infallible?
Not for the people who'd use the wrong type of crimper on the stripped wire rather than buy another (correctly designed) one.

I do like the bullet/barrel connector type with weather protection though, rather than the male/female spade type, and have-since I first saw them on 1960's motorcycles.

 

[goodO1boydws]

So...today i proved without doubt that the Lpump works. By disconnecting the 1 into 2 splice and trying each of the 2 wires independently with key on prime up, i recorded both Lpump and Hpump. So tomorrow at this moment i plan on going to Harbor Freight and p/u the spark tester and maybe even add the CEL bulb. Twice i already know that when it begins to die out fuel pressure goes from 40ish to 10ish or less. So spark tester will be interesting.

One question now is "Why does it seem to run fine with Hpump only?". I ran it for 10 minutes no issue without Lpump connected. Mechanics have told me it can not run without either! I did not drive it but goosed it from idle several times and did not hear any difference.

The high pressure pump CAN pull gas through the low pressure one-for a while....... but that's not what its designed to be doing and it will likely fail soon from doing double duty. Its supposed to work as a pusher pump. (The low pressure one by itself would only work to keep the engine running if you had a carburetor instead of fuel injection, which is what the earliest B2's had.)

Have you ever tried to pull water up through a hose by starting it into suction mode using mouth pressure to prime it? And then push the same water uphill, again using mouth pressure? That's different from having the water come to you already under a little pressure and you're just adding to that pressure.

The 40psi dropping to 10psi really sounds like the high pressure pump may be doing something like overheating and cutting out, or is still running but losing its ability to maintain proper pressure, possible from a voltage drop that only happens after its been running continuously for some time.

 

[Tpremru]

The 40psi dropping to 10psi really sounds like the high pressure pump may be doing something like overheating and cutting out, or is still running but losing its ability to maintain proper pressure, possible from a voltage drop that only happens after its been running continuously for some time.

So it sounds like i have to create the issue then measure voltage at both pumps? Or put 2 lites in the cab with wires connecting in front of both pumps to witness dimming as voltage drop? Or run an indepent power and ground to 1 pump at a time to see if issue still occurs? Or ______? Thanks for ideas?

 

[goodO1boydws]

So it sounds like i have to create the issue then measure voltage at both pumps? Or put 2 lites in the cab with wires connecting in front of both pumps to witness dimming as voltage drop? Or run an indepent power and ground to 1 pump at a time to see if issue still occurs? Or ______? Thanks for ideas?

As a general rule, with any intermittent problem/condition, the best time to get the clearest idea of what is working properly and what is not working properly would be while that problem or abnormal condition exists. (Even if you can only determine what is still working properly it still narrows down the possibilities.)

Also, when trying to nail down an elusive problem/condition, do not change anything about the conditions that exist during the time that the abnormal action is typically taking place while doing the observation. Doing so only adds additional variables to the situation and multiplies the possibilities for the cause of the problem/condition.

By that I mean you should not be doing things such as adding a load to or removing a load from the circuit you are studying, and not be changing the power routing, or altering any grounds before or during the testing.

Using a self-powered meter (has a battery), I would check the voltage momentarily at each pump several times while they are running properly, and then recheck the voltages the instant the problem starts. Do not leave the meter connected in between readings.

You would do well to also check for the amperage draw of each pump while the engine is running normally and again when it begins to stumble.

If there happens to be something wrong with the high (or low) pressure pump-for example if it were to suddenly develop more internal resistance to its pumping action after operating for a period of time that would tend to immediately increase its current requirement as it attempts to continue to operate.

As big of a pressure drop as you describe it, if it is caused by one of the pumps themselves, would almost certainly require a sizeable difference in either voltage or amperage from what they read while both are operating normally.

 

[Tpremru]

By that I mean you should not be doing things such as adding a load to or removing a load from the circuit you are studying, and not be changing the power routing, or altering any grounds before or during the testing.

Using a self-powered meter (has a battery), I would check the voltage momentarily at each pump several times while they are running properly, and then recheck the voltages the instant the problem starts. Do not leave the meter connected in between readings.

You would do well to also check for the amperage draw of each pump while the engine is running normally and again when it begins to stumble.

I think you are saying "don't add lite bulbs or switch to route to an independent circuit".

I have a battery powered multi-meter and i can understand how to check voltage but i will have to speak to mech on how to check amperage draw.

Most important then is how can "I" check the amperage draw and voltage at time of issue? The only way i can see myself being able to do this at ALL is to add 2 wires (hot and ground) on the Lpump right there on the plug running all the way to cab so they can be readily available to connect the voltimeter at issue time, same with Hpump. Otherwise with my physical ailments and anyone else for that matter - to climb under a hot vehicle right away on the side of any given road (if that's when it happens) or even in the driveway. Am i still off base here?

 

[goodO1boydws]

I'll bet that your multimeter probably has about a 6-10A amperage setting, and I'd guess that even a 5 amps max ought to be enough for just one fuel pump-if its running normally.

And here's a fair to good chance that ONLY running matching gauge wires (to what is already there) just far enough to make it easier to check voltage and amperage may not change how it wants to die. After all, it is a B2, so it would only need to be a few feet of wire.

If you have access to help AND what's needed to lift the B2 to get those wires in place, that's all you'd need-if you ran the engine at home. Which is safer in any case.

 

[L\Bronco]

The first few people were throwing parts at it because it seemed simple and inexpensive to do, not actually blaming them for that but that's how it turns out, i think the first guy was more worried about introducing additional problems which quite possibly it has. Henceforth - many directions.

The other shop said they measured for voltage drop back at the pump but i am thinking they just metered it once not while pump is running and not during or after issue not like you described. Your test sounds like the tank has to be dropped to get to the wire ends at the Lpump and the fuel line disconnected? Thanks.

Unfortunately, I think you may have to drop it to make the measurements

 

[Tpremru]

Thank you Motech, L\Bronco, good01boydws & johnnyreb for all your idea's/experience/knowledge!

The one last thing i think about before making and divulging the actual plan is - when issue occurs I only have maybe 30 seconds or maybe 5 minutes most that it will run before it dies and only sputters while cranking. I think i have to jump and open the hood to see spark tester, but probably won't make it to the test leads on FP's. So wondering at that time can i just grnd pin#6 on the obd1 connector, key-on to get FP's running and go visit test leads to measure?

 

[L\Bronco]

So...today i proved without doubt that the Lpump works. By disconnecting the 1 into 2 splice and trying each of the 2 wires independently with key on prime up, i recorded both Lpump and Hpump. So tomorrow at this moment i plan on going to Harbor Freight and p/u the spark tester and maybe even add the CEL bulb. Twice i already know that when it begins to die out fuel pressure goes from 40ish to 10ish or less. So spark tester will be interesting.

One question now is "Why does it seem to run fine with Hpump only?". I ran it for 10 minutes no issue without Lpump connected. Mechanics have told me it can not run without either! I did not drive it but goosed it from idle several times and did not hear any difference.

I was a drivability specialist at a Ford dealer when that fuel system was in service, (don’t do the math) your symptom was very common when the lp pump failed.
The Hp pump is a positive displacement type pump, (it can produce very high pressure, but relatively low volume. If it is primed it can run the engine indefinitely as long as the demand is low.
The low pressure pump is a vane or centrifugal type, it makes very high volume but consequently low pressure.
They work together that way.
When the demand is high the lp pump keeps the hp pump primed.
We need to figure out why you are eating lp pumps.
I would drop the tank, make the voltage loss checks and check for stuff in the tank if I were you.
Hope that helps
Cheers

 

[Tpremru]

I was a drivability specialist at a Ford dealer when that fuel system was in service, (don’t do the math) your symptom was very common when the lp pump failed.
The Hp pump is a positive displacement type pump, (it can produce very high pressure, but relatively low volume. If it is primed it can run the engine indefinitely as long as the demand is low.
The low pressure pump is a vane or centrifugal type, it makes very high volume but consequently low pressure.
They work together that way.
When the demand is high the lp pump keeps the hp pump primed.
We need to figure out why you are eating lp pumps.
I would drop the tank, make the voltage loss checks and check for stuff in the tank if I were you.
Hope that helps
Cheers

Thanks for the insight! The plan is coming together! I have always thought "We need to figure out why you are eating lp pumps." I know the present 5th Lpump (NOS fuel send unit) is working - it sounds good and smooth but of course that is only for about 2 minutes as i short pin#6 on the OB1 connector and climb underneath. I'm afraid to leave it running for longer i don't know if that will "blow up" because i do start to smell fumes when it runs a couple minutes.