There is currently a ford recall on that fuel transfer problem you are having beetween tanks. It may not fix yo;ur other problem but I thought you like to know.
Partsman1006

 

Thanks, partsman1006. Do you know if there's a way to fix it without replacing the fuel pumps? I haven't been able to find details, other than there was a recall.

 

I am not sure about that.
Chuck

 

The fuel xfr problem is due to faulty check valves inside the fwd, aft or both fuel tanks. It causes the return (unused) fuel from the engine to not return to the tank the dash selector switch is on, thus potentiall overpressurizing and over filling the oposite tank. Ford doesn't have any intentions on replacing the pumps to solve the direct problem (where the check valves are) they simply have a kit that's no-charge that they install in about a day. The kit consists of new sets of inline (fuel line external to tanks) check valves and a new fuel pressure regulator in the fuel rails.

I had this problem w/ my duel tank '92 302 a few months back, came up to a red light and saw this spray of fuel running down the rear quarter panel about 25 mins after topping off both tanks. IF you can't get to the dealership, I'd recommend not running either tank to full volume, it allows the tank you're running to return it's unused gas to a non-full tank.

I don't belive that this has anything to do w/ you're stalling, but I hope this info helps.

Dave

 

You guys keep leading toward the faulty fuel tank switch problem for this stalling/running rich problem. But, I had the exact same problem, stalling when cold, crank it a lot while holding the pedal to the floor, and blowing black smoke after it starts and this is with a 90 Bronco which does not have a second tank or fuel transfer switch. I replaced the upper and lower manifold gaskets, throttle body and EGR gaskets, fuel injectors, fuel pressure regulator, cap, rotor, plugs, wires, O2 sensor, catalytic converter, tps sensor, temperture sensor, and probably more stuff I can't remember. STILL have the problem. About the only item I've not replaced is the computer itself.

 

i had mentioned earlier that i had the same symptoms as you on my truckand was tough trackin down, replaced almost everythin, and in my case it was the computer, water had leaked down on it and corroded it and cooked it. see if u can borrow a computer ( i borrowed 1 from a scrap yard) to test if that is the prob.
what do u got to lose by testin it?

 

Looks like I'm going down that same path toward computer replacement as djd67. I've changed about everything you have (except for cat and throttle body - which I cleaned thoroughly) plus several new vaccum lines. I expect to have another computer here this weekend.

Too bad the computer doesn't have a self diagnosis mode or routine.

 

Diskguy, please let me know how you make out and if the computer solves the problem. Since I have the steering column apart in the 90 and I have three Bronco's, a F150, and a F250 I just parked the 90 for awhile until I get it straightened out.

 

DRSWAMPY ....
The fuel transfer problem just started last week on my '91 4.0EFIw/88000 miles on it. It runs fine, just have to be aware of which tank is full. I researched the recalls ... The recall expired 12/31/2001 ... Did you get the check valve kit installed a few months ago? Was it free? Reading your post, I wasn't sure. Can you give me an update on your situation?

Thanks, DR in Dallas

 

yes sir, took my rig down to the dealership, they did it for free. At one point, the parts manager said that they'd had several ppl wanting the update even though they didn't have any symptoms, but when I cranked the truck up and gas started spraying all over their nice clean shop floor, they didn't have a whole lot of "wiggle room". as mentioned b4, the kit involves a set of redundant check valves inline to each tank, and a new fuel pressure regulator.. the parts bill/invoice was aroun $170 if I remember correctly, and it was no charge. Was done back in July of this year. Hope this helps.

This may sound silly to ask, but have you verified that the EEC isn't in limp mode? I doubt that the whole unit's fried, if you have the E40D, a quick checking to verify that the 'noids are firing into each gear as should would tell me the EEC's ok.

 

Not silly.
How do I check for "limp mode"? I suspect it is.
Not sure I understand about firing 'noids. ??

 

The EEC has a "limp" mode, which is nothing more that a default parameter when a significant sensor fails. Instead of tring to produce a computer strategy with erronious data, it just goes into a safe mode, hence "limp". 'noids = solenoids. Solenoids affect the shifting of gears by the bands inside the trans.The tranny has a potentiometer called the manual lever position sensor (MLPS), it tells the EEC what gears your gear selector is in, if the EEC is fried, the tranny would be running in a limp mode as well, which would produce very hard shifts and higher RPM shift points due to higher trans coolant line pressure.

 

One thing I forgot to ask, you haven’t made any significant changes to your engine have you? i.e. cam, heads manifold etc? Your year truck is more sensitive to major changes from the stock configuration because the EEC calibrates and makes fuel adjustments off of speed density as opposed to mass air.

 

diskguy, after thinking about it.. have you checked your TAD and TAB controls, and the operation of the air diverter valve to the rear of the heads and the cats? I had a problem with mine that was starting to develop exactly like several of you have described, slight surging at idle, running rich when cold etc. I just caught mine early. hope this helps.
Dave

 

The only thing I've don is to put on a K&N Air filter/intake. I was having these symptoms previously. The truck was running better after installation of K&N. It's been getting steadily worse.
Tranny seems to shift fine except when coming to a stop - then sometimes the torque converter will lock up & the truck will stall. That's always fun!

Not sure about the TAD & TAB controls???

Thanks for the input...