Hello,

I have a f350, 460cu in EFI. Very rough idle and lotsa black smoke.

Last week I replaced wires, plugs, cap & rotor and fuel pump relay.

Fuel pump is 6 months old.

Scanner results:

KOEO:
556-fuel pmp relay primary ckt

Engine Running:
173-ego not switching, rich exhaust - bank 1

Cont. Memory:
126-map or baro snsr out of range
173-ego not switching, rich exhaust - bank 1
212-no tach input to processor-spout
334-egr(evp) voltage above closed limit
542-fuel pmp ckt open-eca to gnd

We cleared codes and ran a second time and got KOEO:556; KOER:212,542

My friend who scanned it was concerned about the following info from the scanner:
SFTRIM - in closed loop read (-23); after a couple of minutes it switches to open loop and reads (+11) and stays there.

He is wondering about the O2 sensor...

Any advise would be appreciated! Thanks

 

You will need one of the EFI experts to interperate the codes but it sounds to me like the Fuel Pressure Regulator is bad. Pull the vacuum pipe off of it and see if there is any gas in the pipe, if there is then replace the FPR. If not then I would do a fuel pressure check. Hope this helps.

 

+1

Until you check your fuel pressure, I wouldn't bother with anything else.

 

What should the pressure be?

 

It should be 40-45 with engine off. Check the vacuum line on top of the regulator for fuel as well. Pressure could be fine, but a broken diaphragm will send unmetered fuel through the vacuum line to the intake.

 

It measured 80lbs with key on, and vigorously bounced between 80-85lbs while running...
no fuel present in hose or stem atop the fuel pressure regulator...
I am planning on replacing fuel pressure regulator today...

 

...So, I went down to the auto parts store & chatted with one of the fellas there who is a "Ford Guy" (used to own a wrecker as well...)
He said 80lbs pressure on fuel sytem isn't outta whack... depends on the engine... he said he's seen it as high as 115lbs or so...
He said to go home & verify what my pressure should be. After looking at Chiltons online, I figure I should be between 40-45lbs.

I DID NOT replace my fuel pressure regulator (at this point).

Please Help!!!!

All input is greatly asppreciated...

 

Key On Engine Off 35 - 45 psi
Key On Engine Running 30 - 40 psi
For a '93 f350 7.5l

 

...by the way...(forgot to mention, since it's been 6 months since I've used it...) today I put $20 propane in the tanks (yes, it's dual fuel...)
I haven't run it on propane in 6 months; as last summer, it ran quite poorly on propane. I changed the propane filter and noticed it was fouled up with silvery "glitter flecks".
Ran fine for a day, then back to running poorly.

TODAY, I decided to test it on propane... Much to my surprise, it ran VERY well.

So, I am certain that my issue is with the GASOLINE side of the fuel delivery system...