86 Bronco 5.0 EEC-IV

[Anthony1965]

I've checked a lot of things on it, and the one thing that concerns me now is the injector pulse width. I'm seeing a pw of about 18-20ms while cranking. I can't seem to find any info on what it should actually be for this system (EEC-IV injection) while cranking, though. Anybody know what it's supposed to be? Also, if you've run into this situation before, or have any suggestions, let me know. I've checked PIP and SPOUT, and both look great. Getting good spark. I'm guessing the computer itself (worst case scenario) or the MAP sensor. Thanks for the help.

 

[davidmcg]

I've checked a lot of things on it, and the one thing that concerns me now is the injector pulse width. I'm seeing a pw of about 18-20ms while cranking. I can't seem to find any info on what it should actually be for this system (EEC-IV injection) while cranking, though. Anybody know what it's supposed to be? Also, if you've run into this situation before, or have any suggestions, let me know. I've checked PIP and SPOUT, and both look great. Getting good spark. I'm guessing the computer itself (worst case scenario) or the MAP sensor. Thanks for the help.

MAP sensor alone shouldn't be the problem. I am not an expert by any means. Take a look at the problems I have, I have a thread here on my '89 that won't start. On yours, when did this appear? Was it running and die and then not start or did you go out one day and it wouldn't start? Are you sure you are getting fuel up to the injectors? Actually the computer isn't the worst case, a spun lobe on the cam would be worse. In the case of my Bronco it has been suggested that the Throttle Position Sensor should be replaced. Hopefully I will be able to install it by the weekend.

 

[Anthony1965]

It was running one night when I lost virtually 50% of the power in the engine. Struggled to make it back home at like 40 on the freeway. After I got home and shut it off it's been crank no start since. Fuel pressure's good, spark is good, TPS is good, blah blah blah. I'm pretty certain the problem is the rich mixture. But I could be wrong. Maybe the injector pulse width is correct, it's just a lot longer than typical fuel injected cars. The MAP sensor is a major input in determining injector pulse width. Since the O2 sensors aren't working during cranking, it's virtually the ONLY sensor that essentially tells the EEC how much fuel to inject. It's not something I can't chase down myself, just looking to shorten the chase. ;o) Thanks for the input, though.

 

[Seabronc]

I'm not an EFI guy, but take a look at this site http://fordfuelinjection.com/ maybe it will help.

Good luck,

>-

 

[Anthony1965]

Very Nice. Definitely some good reading there, thanks.

 

[Blue beast]

Have you made anybody mad lately? Maybe they put some water in your tank or something worse!!!! Did you fill up at a different gas station lately or

did you fill up just before this happened? Get a bottle of gas line dryer, pull off the fuel filter, press the valve on the fuel rail, Fill the filter up with the gas line dryer as much as possible hold your finger over the outlet connect one side then quickly connect the other side, Crank the engine for a couple

rotations let the gas line dryer sit in the injector rail for 10 minutes or so, You want it to bond to any water in there try starting it if it runs, You will need

to triple dose what is in the tank. Get 2 bottles of heet and 3 bottles of iso heet dump them in the tank 3/4 1/2 1/4 whatever run it until 1/8 tank refill

with fresh gas and add 2 bottles of iso heet or stp gas treatment. If the filling station just got a shipment in, The water that is in the station tanks get s swirled up along with dirt and crud, Try to stay away from a station that just got a delivery. Not to mention the water that is in your tnk to begin with, With gas prices as high as they are and the big tanks in these broncos, Alot of people are running around on empty tanks and all that empty space lets

water condense. Leading to not only water in the fuel but scale rust on the top of metal tanks which when you fill up or hit a big bump gets slough off, and all that rust acts like razor blades on your fuel pump internals eventually degrading it's performance!!

 

[Anthony1965]

Doubtful it's the gas. It was running just before all this happened, and the guage shows 1/2 tank left. Not to mention, the guage shows empty after 16-18 gallons, and the tank holds 32 according to the manual. I should hope I don't have that much water in the tank.

 

[Blue beast]

Water has a higher surface tension than gas and just a tiny bit can hold onto the tiny opening that is the injector and not let the fuel get through. Trying

a few bottles of dedicated gas line dryer is way cheaper than throwing sensors or tearing into it. $8.00 for heet can save you alot of money and putting in a bottle every oil change can stop headaches before they begin. It seems that since FI became widespread people have forgot the havoc that

Dihydrogen monoxide can cause!!

 

[Anthony1965]

Water's not the problem.