weird problem-puzzled

[Kalwren]

Excellent information, thank you. I can do this.

On another note, if this does turn out to be the problem that the original poster and I are having...

Is it possible to take an intake manifold from a '95 up V6 Cologne and put it on a '94 engine? If all I need to do is swap the intake manifolds to fix my problem, I'll be all over it.

Thank you again for your help and I'm sorry if I've jacked someones thread. It just sounds like we're having the exact same issue.

Ok, on a '93-94 Ranger or explorer the relay simply plugs into the top of the
load center box.

If you pull the relay the relay is marked with a circuit diagram

All you need is a 2" length of a 12ga or 14ga wire with a MALE
1/4" slip terminal on either end that you can plug into the
switched contact terminals in the circuit breaker box.

ONE of the terminals is hot at all times (wired directly to the battery)
the other feeds the 12V to the fuel pump

When you install the jumper you'll hear the pump running
and if the system is vapor bound you'll probably hear a
gurgling sound.

It's all about heatsoaking the fuel rail.

I'm not 100% sure it's the lower intake or ONLY the lower intake that's different,
but I DO know that the '95-up 4.0's have that 1/4" plastic spacer between the
fuel rail and the lower intake and I have yet to hear of someone with a '95-up 4.0 complaining about this exact set of symptoms.

AD

 

[Kalwren]

Another question about this process.

I bought the wire and male ends that I needed and I've created my jumper wire.

I looked at the relay for the fuel pump. It has 5 posts on it! 3 down the center of the relay and 1 to either side.

When you jumper yours, can you tell me which slots you're jumpering into please? I don't want to connect the wrong ports and risk causing damage to my electrical system.

If you could even show a photo, that would be super excellent.

Thanks again for your help! I'm still troubleshooting my gremlin.

I've answered this before and it's a fuel problem more
than a fuel system problem, but the design of the fuel system
is partially responsible.

the common complaint invariably comes from someone with a 1990-94 4.0.

the issue is related to the ammount of butane that the federal government allows to be blended into "winter mix" gasoline.

Butane boils at 0.5degC but boild higher when dissolved in gasoline.

the reason the problem doesn't affect the '95-up 4.0's
is because there is a 1/4" thich thermal isolator between \
the cast aluminum fuel fuel rail and the aluminum lower intake.

the design of the fuel rail in the other engines used in RBV's doesn't
heat the fuel to the same degree because the rails all "float" above
the lower intake.

the other factor is that the ports in the fuel rails are at the highest point of the
rail so while there may be liquid fuel in the rail the top feed end of the injectors
so the inector feed point is "high and dry"

the correction to the problem is to either:
A)replace the fuel railand/or lower intake and add the thermal isolator
B) cycle the key repeatedly in an attempt to pump cool fiuel from the
tank through the rail to collapase the vapor bubble
C) carry a jumper wire to connect the switched terminals of the
fuel pump relay socket and let the fuel pump run for the length of one song on your sound system before attempting to start the engine

BTW, jumpering the relay for 2min and sucessfully starting the engine
is a positive diagnosis for this specific problem.

In case you are wondering, yes I have this problem on my 1993 engine.

Swapping out my lower intake is part of the long list of things I need
to do before I make my next trip to Wyoming.

AD

 

[Earl43P]

Jumper 30 and 87 (if you look closely at the relay, it has these terminals marked - you simply jumper those spots in the relay socket).

Google "Bosch Relay Guide", download it and learn from that.
Aw heck, here: http://dlcparts.com/images/BoschGuide.pdf

 

[Kalwren]

Sir, you are THE MAN!!

I want to exceptionally THANK YOU for not only explaining this, but providing absolute proof of what you were saying.

To make sure I didn't blow up my electrical system, I reviewed the document that you linked and checked your work.

Then I double checked it. Then I checked it again, because I can't afford for my truck to take a gigantic crap on me.

After reviewing your information about the relay and building my jumper wire - it absolutely works.

The only difference is that the document shows post #87 (on the relay) as being on top, when it's actually at the bottom.

Being electricity flows from negative to positive, I stuck my jumper into post #30 and then into #87.

The fuel pump starting running and didn't miss a beat.

So... Now I'll try this the next time I have the "Hot Engine, No Start" issue, which should be tomorrow when I go to Wally World (Wal-Mart).

THANK YOU FOR YOUR EXPERTISE! I appreciate your time and effort looking into my issue! You have my gratitude!

Thats not just for Earl43P, it's for everyone who has offered insite into my problem and given me an avenue to explore and resolve my issue.

It still persists, but I'm tracking it down. Isn't that what Rangers do?

Jumper 30 and 87 (if you look closely at the relay, it has these terminals marked - you simply jumper those spots in the relay socket).

Google "Bosch Relay Guide", download it and learn from that.
Aw heck, here: http://dlcparts.com/images/BoschGuide.pdf