[QUOTE]Originally posted by blue_mule

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The manual fuel tank selector valve (dual tank system)malfunctions , when running on the back fuel tank the selector valve may malfunction and cause the back pump to over fill the front tank. This happens more often in warmer weather.

When running the front tank it the engine may stall while cruising, or under hard accelaration.

the manual selector valve mounts on the left frame rail in front of the front tank. It looks sort of like a large fuel filter but, it has 6 fuel lines going into it. 3 main lines and 3 return.


Was the only fix to go to a manual selector? I just bought a 91 Club Wagon and it has an electrical toggle switch. How would I know if the van was taken in for the recall? Is there a difference in the old vs new switch or was the electrical switch eliminated as the ONLY fix?

 

The toggle's ONLY function is to switch from front or to rear fuel pump.. Remember it only switches pump to pump... fuel pressure is what switches the valve.

jpsartre12, Call the FORD customer Service hot line. It's an 800 or 888 number, or your Friendly Local dealer can look it up on their computor, i think..

 

Thanks Blue, I'll do that. Maybe that's why I only get a little over 10mpg.

 

Ignition module on the fender drivers side is failing. I went thru this problem with my '83 E-150 5.0l I thought that is was fuel related and changed everything only to find that it was a $15.00 module.

 

that's what i thought, that's also the first thing i changed

 

Would the fuel tank selector valve result in one of the tanks not registering on the dash indicator? Also does the icm cause mpg to change> as the problem got worse I got less and less miles per gallon. I think I have had more than one problem going on but I am not sure. One thing for sure when I switch to the front tank it does not register on the tank indicator and I know there is gas in it.

 

"quote" ... Would the fuel tank selector valve result in one of the tanks not registering on the dash indicator?

That , I am not sure about ,
Although my front tank gauge would not register...

I couldnt tell you about problem with ICM.

 

I am going to get the icm tested this weekend, but I think it is the fuel selector valve that is the problem. Now the only problem is finding the dang part. I haven't had much luck so far finding one

 

I'm a bit late here, but here goes...

The ignition module is known as the TFI module. On your van it is the grey colored small plastic box attached to the right side of the distributor as you look under the hood. Later models did move them to the firewall in a (futile) attempt to stop the internals overheating. It will have a large connector facing you. It's held on by Torx bits usually. Also, to remove it, you pull it straight down. It looks like it will pull off towards you, but believe me it doesn't! It's hard to get in there, but not as hard as pulling your distributor & accidentally jumping a tooth. Advance or AutoZone will test it for free. You can also run a hairdryer out there & heat it for a couple of minutes when the van is cold, and see if it still starts.

My rear fuel gauge doesn't work, and now mine's started filling the front tank when I use the rear. It spewed a bunch of gas out the other day (which is why all those ambulances went on fire!) and when I started it, I heard the real pump grind due to the empty tank. What was really strange was that it continued to run: looks like the high pressure pump was actually sucking it out from the front too, because I went back to listen to the rear tank and the in-tank pump wasn't running. There is an big inline fuel filter, along with pickup screens on the intank filters. You can't buy the senders seperatly, you have to buy it with the pump.

If you look underneath the drivers side, you'll see a round black thing with 6 hoses on it. Thats the fuel tank selector valve that blue_mule mentioned, although you might be lucky & find a bad o-ring in it like a buddy of mine did.
I've seen them on eBay the odd time or two, am wishing I'd bought one now!

Now, back to the problem.
You've got terrible gas mileage, your van dies when hot, and if you crank it WOT to turn off the injectors she'll fire a huge cloud of black smoke out of the exhaust & then die again. I bet it also almost dies when you shift from P thru R into D and again when you press on the gas. If you let it start to take off by itself, then gas it, it dies slightly then comes back to life. If I'm right, then leave the TFI alone for now, and read on.

Mine did the same thing, got 6 mpg etc, and I replaced all sorts (incl the injectors) to get it running. Turned out to be a $15 sensor. The van has 2 temperature sensors: one goes to the dash, the other goes to the computer & my money is on that being bad. Basically it tells the computer that your engine is at -40 degrees, so it happily floods your engine by holding the injectors open longer. Look at the front of the engine, and look at the cooling pipes & you'll notice a sender unit with a black connector on it, it faces you & is in horizontally. If you unplug it next time it dies, I'd bet it starts right up again.
It doesn't throw a code, although you might notice a 21. (Do a search for pulling codes, you can do it with a paper clip).


Apologies if I've repeated what others have said ;-)

 

I'm more familiar with Chevy's computer controlled fuel injection system, but doesn't Ford also employ O2 sensors to monitor A/F ratios and a PCM to adjust the injectors duty cycle accordingly?
Of course, if the vehicle never gets into its closed loop operating range, the computer would never adjust the injectors since it would be bypass the O2 sensors' inputs.
(All of this assumes that Ford and GM EFIs behave similarly.)

 

Yes, there is a single O2 sensor on the right side.
It's ignored to start with, until it goes into closed loop.

However, if that temp sensor is bad, the EEC-IV PCM will always assume that the engine is stone cold and will hold the injector pulse time longer, even if the O2 sensor will be screaming rich at it. I know nothing about the Chevy system, but I do know this one.

 

Sounds similar to GM's PCM controlled EFI. It stays in open loop, or "limp mode" if sensors fail, keeping it running but like a pig. I was told that the main reason for that is because the O2 sensors have to be hot before you can trust their output. It's interesting that there is only one O2 sensor. My 94 Z has one per side and they are independent. You can identify exhaust leaks, bad plugs, etc by looking at the balance between left and right banks as a result.
Is there a good reference source for Ford's EFIs?
I have a 91 302EFI in my van and I'm a Ford nOOb.

 

I think the 91 still only has the single O2 sensor, I can't remember when they changed to duals and then HEGOs. You were told right that they have to be hot before they stabilze.

Limp-home mode in the EEC-IV is actually pretty good: mines been running in it for about 8 months now.

 

My 94 Z28 Stroker has been running in it for probably 4 years. I recently bought the car and hope to figure out why by next spring. At 8mpg, it's a killer.

 

Good Lord! It has taken me over an hour to find this page!

This is, you may have guessed, the male significant other of Alley, aka, Tj.

Now, what I've found out.

After my boss spent about $1,000.00 to replace every part of the fuel system, including the gas tank, filler tube, all pumps and filters, and you name it, his Ford Econoline Van (yup, read that as "E150 or F150, Van or Truck!") did exactly the same thing!

302 won't start when warm!

And, for kickers, it has only one fuel tank, so, no, fuel tank selector is a totally separate problem.

Ran into an older couple from Florida going to visit their military son in South Carolina and noticed they had an E150, 1990.

I asked them if it ever had a starting problem and did the front fuel tank stop reading and what did they do about it?

They said yes, it would stall and the front fuel tank read zero all the time.

Their mechanic then simply reached under the hood, to the TBI, and bent back the metal tab that sets the idle via the automatic choke or whatever it was, which raised the idle, and kept the van running!

Now, here's the goodies, there are a couple of problems here, maybe more than three, but definitely at least two!

One, timing retarding will stall the motor and cause it not to restart until cold; that's the job of the automatic choke and the "shorting bar" which, in fact, does retard the timing 3 degrees.

From my 1950's and 1960's automechanics training, advance the timing and speed up the motor, retard the timing and slow down the motor. Make sense?

Second, the condensor, if shorted, will lower the spark from the required 50,000 volts to under 25,000 volts where there simply is not enough electrical energy for ignition.

Third, after ten years or so, that springy looking thing on either a carbouraetor or a Throttle Body Injector, or whatever, is going to get either stiffer or looser and change the timing of the whole thing.

When you get back to Internal Combustion Engine Theory and Operation, back to the Diesel brothers, and other guys who invented the engine, you'll find that ten or eleven degrees before top dead center is required because of the physics of mechanics, and, even the dumb Saturn V has to obey these basic laws, like, the delay in the actual explosion while the piston is still travelling, compression of the gases (Boyle's Laws), and a few other goodies like Faraday, Maxwell, and other guys who worked on the first engines.

In any case, the analysis is not completed yet, but it will be. And, when it is, it will be posted for the world, especially the alleged A.C.E.'s out there who claim to know automechanics.

This problem is occurring with every E150, not just one or a few, but all of them, and it is amazing that not even Ford has answered this yet. Are they no longer hiring real engineers? That is, have they stopped hiring degreed people in favor of Chinese, Pakistani, and other slave labor?

The Dr.

That's the aboriginal "Dr." from the Philadelphia Bulletin Board, founder, automechanic, and electrical engineer/computer inventor and designer.