Finally got the fuel used up and lowered the tank. Old pickup was completely broken off. Could not find one tiny piece of plastic but I'm ok with it. You can see the piece missing below.






Pretty easy job, took couple hours. Test drive was good with solid 70psi and no fluctuation. Gotta get the skid plate back on tomorrow.

Pretty happy with it. I'm still planning to put a new HFCM in but for now it seems pretty solid.

 

Well after driving around a bit over the weekend 2 things happened.

First I went to start the truck after driving earlier that morning and when I turned the key the starter did nothing. Started it up from under the hood with the starter wire to battery terminal.

Next day it started fine. Running around, went to start and FP only came up to 50-55. This was after driving a bit and everything was warmed up. Didn't have far to go. Little while later it came up to 70 right away.

I still haven't tested the the voltage/amps to the fuel pump yet and at this point I'm thinking there's an intermittent issue with the fuel pump relay and possibly ignition circuit but not 100% sure yet.

What I'm wondering, I see there are remanufactured Fuse boxes on eBay. They are replacing corroded connectors and built in relays apparently. Anyone have any luck with those or know of someone using them?

I'm just thinking if my fuse box connections are getting bad, maybe that's a good option.

The other option is to do the external relay for fuel pump and try to figure out what's going on with the ignition.

 

The PCM is pretty reliable at throwing THE code for a failing fuel pump relay. P0231

 

Thank you, I appreciate that info. There are no codes. Any ideas what else may be the issue?

Ordered a new FICM that should be here by early next week also .

I'll be using my truck for towing once the fishing season starts in a couple months so I have some more time to get it figured out.

 

What are you using to pull codes? Many will not do a thorough job of it.

 

That may be it then. I'm just using Torque pro and SCT.

I had Forscan Android but it is not working any longer. Been wanting to get it on the laptop for the Bronco to adjust a few things.

 

In the past, Torque Pro has seemed to be decent (SCT hasn't ever been good at it). I have seen a few reports recently on Torque Pro missing some codes. Not sure what that is about. Anyway, FORScan has still been the most reliable for getting all the codes.

 

Got it. I'll get Forscan on the laptop

Just did some tests of the voltage. Battery voltage was only at 12.4 currently so they are on the charger now. Cycling the key the fuel pump was getting 11.7V and Inertia switch 11.5V for whatever that is worth. Seems good to me.

The fuel pressure is dropping to zero and the pump has to build pressure each time. Today it would only come up to 50psi while cycling the key. Then when I start it the pressure usually comes all the way up to 65-70. That seems off to me, I can remember it coming up to full pressure by cycling the key before all this started.

 

So when you tried cranking with the key, you did not even get the starter engaged, but did engage by jumpering it to the passenger battery? If this is correct, it reflects more of an issue with PCM power than direct power to the fuel pump. IMO anyway! There are numerous problems that can impact power to the PCM from Fuse F2.22. You have probably already done so, but I always check and double check my battery health as a first action (charge and load test individually). Still there could ALSO be something "intermittent" going on with the fuel pump/relay/wiring.

 

Yeah it did absolutely nothing when I turned the key to start. Drove up to the hardware store and got some things and it started fine on my way home.

That doesn't sound good about the PCM. Is there any way it can be tested? When it happened I did some basic troubleshooting like swap the relay and check the fuse but it definitely seems like there could be some electrical issues happening.

Neutral/park switch or whatever out of alignment? I don't know, from searching around I came across a few posts mentioning that and some people mentioned they had it happen like once and never again. Maybe the lock cylinder I bought a few years is having issues. A few years ago when my truck was stolen it had to be replaced and I remember something in that area was broken.

 

There are several critical circuits that can commonly impact the PCM supplied power:

• Fan and/or clutch wiring/connector
• IPR and/or wiring/connector
• GPCM and/or wiring/connectors
• EGR and/or wiring/connectors

Look at the connectors and wiring on/to those components first.

 

Thanks I will look into those connections. I did see you mention the fan clutch wiring about this elsewhere and disconnected it to troubleshoot when it happened. Forgot to mention that earlier.

 

Add the MAF to the above list also (if you have one).

 

Sounds good and appreciate the advice on those connections. Hopefully they are ok. I went through the harnesses last year when doing the heads and did have to replace 2 or 3 connectors because the wires at those locations had insulation breaching from oil. Took my time to really clean them up and retape any areas of the old wire loom tape that needed it but who knows.

Tonight I installed a relay in parallel with the existing stock fuel pump relay. I figured if that's not the problem, at some point it would probably fail so now there is a redundant circuit in place to run the fuel pump.

Supposedly the new FICM is coming tomorrow. When I get around to changing it, I am going to also drop the fuel tank a bit to replace the fuel line from the fuel pickup to the pump. I have no way to be sure the current fuel line doesn't have a suction leak. Replacing with heavy duty fuel hose and clamps to be sure theres no suction leaks.

After that I can't possibly imagine what else could cause my truck to have fuel pressure issues. Should be good to go.

 

Slowly getting there, didn't have enough fuel line so got some on order. Swapped out the HFCM tonight and test drive was good. We'll see over the next few days how it's acting.

The fuel pressure relay was not the problem. It was acting really odd with fuel pressure dancing all over the place a few times and that was just a short trip to the store. That's why I just decided to do the HFCM tonight.

Also out of curiosity opened up the old HFCM. Overall pretty clean but a few pieces of the old fuel pickup foot in there and some sand/dirt. Probably could just clean it up and keep it as a spare. Maybe put a new pump in it. I don't fully understand the flow through the manifold area but I'm wondering if the pieces of the pickup foot were going into the pump and causing issues.


Dirty stuff in the filter housing



Little bit of sludge and nibs off the old fuel pickup foot