I'm at my wits end

[KingTut]

Ok, so I had the fuel pressure tested and with the KOEO i had a reading of 0lbs. It wouldn't move until I started the truck up. Does that sound right? With the engine idling I had a reading of 54 lbs. I read in the Tech library that it should only be 30-40 lbs. Does this sound right? Also, shouldn't there be some kind of reading with the KOEO. Any thoughts? If this is the case what am I looking at... A bad fuel pressure regulator?

 

[KingTut]

Any thoughts?

 

[bobbywalter]

I'm not sure. I need to have a vacuum test done. When I took it to my local shop, I asked them if maybe I had a vacuum leak. The guy told me that since it was running rich, a vacuum leak was ruled out becuase it would cause the truck to run lean from extra outside air entering. I'm not sure if maybe that's were you were heading with a vacuum leak, bobby, but I may take it somewhere else for a second opinion. Anythings a possibility at this point.

theres alot more to a vacuum test then simple intake leaks.....valves not fully seating etc are visible in many cases.

 

[pjtoledo]

Yes, its the 3.0 Flex fuel engine.

on a flex fuel truck there is an electronic module in the fuel line. that module determines what the gas to alcohol ratio is and sends a signal to the computer. alcohol has less energy per volume than gas, so to get the same power out of an alcohol mix the computer increases the amount of fuel injected into the engine. thats done with longer injector times, not increased pressure. if the module is giving bad readings the engine can run very rich, to the point of not running at all. my 2000 failed that way a couple of years ago. back then new flex modules from Ford went for over $600. there is an online vendor someplace that sells a box that simply tells the engine its on 90% gas with 10% alcohol and to run that way. mileage ain't the best, but its still running.


whoops!!!wait a minute folks,,,,,just pulled the Haynes book out and it lists 47 to 63 psi for the fuel pressure on 98 and later 3.0 flex fuel,,,so your 54 looks just fine.

 

[Hagan]

Did you try cleaning the maf? You said you replaced/checked it. Same things happen to my moms Corolla.

 

[pjtoledo]

to check the module you need something that reads a DC square wave signal. the frequency of the square wave changes with the amount of alcohol in the fuel.

 

[KingTut]

Ok so the fuel pressure is "normal"? Bobby says its low, the tech library says that 30-40 is the normal making my reading high and couple people saying that its in the normal range. My head is spinning.

 

[KingTut]

I haven't tried cleaning the new MAF. I cleaned the old one but it didn't change a thing.

 

[bobbywalter]

you should have a returnless style.

its 55-80 psi iirc



with your codes i am suspicious you have a short in a powercircuit related to the o2 system.

check the o2 sensor heater circuit voltage and the voltage to the dpfe systems and related fusing...

 

[KingTut]

Ok thanks Bobby will definitely check that out. Thanks for clearing up the fuel pressure reading.

 

[pearblossomal]

Did you check the fuel pressure regulator? I assume it's on the fuel rail that uses vacuum against a diaphragm.

I've seen acceptable fuel pressure in the rail with a ruptured/leaking diaphragm that allows raw fuel to be sucked into the vacuum line.

 

[KingTut]

I've tried removing the vacuum from a black cylindrical valve/sensor near the rear of the fuel rail to see if there was fuel in the line,no fuel in this vacuum, but from what others have told me, the the FPR is in the fuel tank.

 

[xr75er]

when it comes to the EGR most people forget to clean out the manifold opening for the EGR. it plugs up with oil and cooks in place. might want to check this passage.

 

[KingTut]

Ok so took it to the dealership and they told me that I would need a new PCM. Since I was getting codes P0135, P0155 and P0141, the guy said that none of the heaters for my O2 sensors were working. He checked the wiring and it checked out so there was no open circuit. He ruled out bad O2 sensors becuase I was getting the codes P1132 and P1152 which is the O2 sensor indicating a rich mixture. So with that being said, anyone have experience with changing out the PCM? What kind of damage to the wallet am I looking at?

On a side note, Is this something that I can do and then take it to the dealership and have the new PCM reprogrammed or are dealerships funny about that kind of thing? Thanks guys.