That's what I figured. Yeah, I cleaned the IAC passages.

If you ever surfed the ford forum I'm on you'd see me make mistakes like that regularly lol...

 

If/when you replace the pump, don't go el cheapo, use AC Delco or Delphi only. If you don't, you'll be right back in there doing it again in a short time. Lifetime guarantee is great, but wouldn't it be nice to only do the job one time? That's why AC Delco/Delphi is the pump of choice Granted, it's a mechanical part and it can have problems too, but they're rare. They're usually good for 100K miles, not the case with aftermarket pumps.

 

Just picked up a Delphi pump... got the old one out this morning...

Just out of curiosity, how long can I expect this thing to last if I take care of it?

It has 194,000 on it IIRC and it has good oil pressure...

 

I service a fleet of 4.3's and the highest mileage one has 372K miles and is a daily driver. Engine, trans and rear axle have never been apart, (other than to replace intake gaskets). Another one has 286K, same story with that one. My personl daily driver has 203K miles. Take care of them and they'll take care of you.

 

Agreed... that's the trick to the whole thing... Nice to know I might squeeze another 100,000 miles out of this money pit...


Installed the new Delphi fuel pump. Produces 105 psi when energized, holds 50+ psi for 10 minutes.

Still lose pressure almost immediately at the manifold. No visible leaks in fuel lines from tank to manifold.

Injector?


Let me know what you think.

Thanks.

 

Now you know that the pump is not leaking, so, if the pressure drops when everything is hooked back up, there's either a leak in the plenum, or the pressure line from the filter to the plenum. If the pressure line is leaking, you would definitely see it leak on the ground. It could be one or more of the poppet valves are leaking. With the plenum removed, gently pull the nozzles from the ports. Then cycle the pump, (don't crank the engine) and watch for leaks from the nozzles, they should not leak. If there is a leak, the only fix is to replace the spider assembly, (the poppets are not serviceable).

 

Ok. Will split manifold and check the poppets. Post results when I get them...


Thanks!!!

 

Xenon....If you take the plenum off just spend the money and replace it all if possible. I had the same problem with my 95 Blazer and tried taking the cheapest way out possible. In the long run had to take plenum off 6 different times and replaced the FPR because of washing on that side of the intake. Wasn't that...took apart again to replace nut kit and that wasn't the problem...took apart again to replace spider injector which already had a new FPR attached soooo.....wish you the best of luck.

 

That's pretty much where I am now....


Question: are there any tricks to removing the poppets? Half of them came right out, the other half are pretty stuck... Stuck with carbon I guess... How do you get them out without breaking them?

Thanks!!!

 

Cycle the pump and watch the nozzles that you have out. If you see any leakage, the entire spider assembly must be replaced. You're right, there's probably carbon built up around them. Try spraying a little carb cleaner around them, let it soak in then gently wiggle them.