uncommon irritation

[rjs]

hello any and all. Ive just recently registered and have been doing some searching to no success.

first of all i have an 87 ford bronco 2 and it runs great, passed smog with flying colors. just couldnt ask for it to run any better.

recently tested battery, alternator, starter, and wiring in between. everything tested fine.

next tested the fuel pressure and have 42 pounds quickly after the key is turned to the on position. when running its around 33 pounds. however very rarely the engine will start to sputter a bit and the fuel pressure will rise untill it clears out and the pressure returns to 33 pounds. when the key is turned off pressure automatically drops to what looks like 0.

now onto the irritant, first time starting it will take a few times cranking to fire up then runs fine. if shut off will fire right back up fine, but if allowed to sit for long period of time will be hard to start again. cleaning the battery connection decreased the amount of tries by half, but it feels as though it needs to have a first spin and then will fire right up on the second. the only factor it seems is how long it sits between starts, hot or cold doesnt really seem to change anything.

now onto the questions. when the key is turned off should the fuel system retain any pressure, how much and for how long? when in the start position the coil reads 9.5 volts but goes back to 13.5 i believe when in the on position, can this be a problem? the manual says 40 pounds in the on position and not started, im a little above that. could it be flooding the engine and needing that first spin to clean it out? any thought would be appreciated.

just a side note, i pulled out the ecm and i think it said it was for a ford sable/taurus only on a sticker. couldnt find any numbers or anything that cross reference it with a ranger or bronco 2 at the parts store. any thoughts on this would be appreciated as well. thanks for your time.

 

[adsm08]

The return type fuel system will retain very little if any pressure for more than a few minutes. The pumps run as long as the computer sees a rotation signal from the engine, this is why it fires after you crank it. Cycling the key will produce the same results.

It sounds to me like you are having feed-side drain back issues. I'd get a new fuel strainer unit, the check valve is in there. I know Ford stopped them but I think you can still get them from NAPA.


I wouldn't worry too much about the sticker on the computer. That seems to be a common thing, but given the similarities between the control system of the 2.9 and the very early 3.0 I can see the 3.0 computer working in the 2.9.

 

[rjs]

thanks for the reply, what is the fuel strainer unit and where is it located?

 

[adsm08]

It has a screen and a reservoir and a check valve.

If you hop under and look next to the transfer case it is the can-shaped thing with the fuel lines running in and out of it.