[The Todd]

Hello, my 'ol Pick Up Truck needs help. I don't drive it much anymore because of the suspension rust and the mileage, etc. It normally runs great however. I thought it was the Fuel pump. I've changed it before ~8 yrs ago. Recently I think it's been acting up again.
I have put a pressure gauge on the fuel rail- and when it runs- it's with in spec- 48PSI.
Sometimes it won't start and no reading on the pressure gauge. Other times it starts, 48#, and yesterday near my home it ran poorly- like the fuel pump is intermittently gong out.
When it wouldn't start, I sprayed something in the throttle body, it would fire over briefly- hence I feel it is a fuel flow issue. Randomly other times, it starts right up.
* I checked the codes today - Zero codes! If the fuel pump had occas. low pressure- THAT should throw a code- even w/o a dash check engine light.

I've checked the 2 fuses that could keep the fuel pump from working, and swapped regulators around, no difference.

Today, I started it and drove it in my neighborhood again. Once it had a dying like idle- never died.

I bought another fuel pump- top of the line one from Rock Auto. However with the NO Codes thing- I'm not so sure that it is the fuel puimp?

* Changing it is a MAJOR PITA- the straps that hold it up are so rusted, etc.

My favorite local shop quoted $650- with THEIR fuel pump- they will not install a brand new one I have.

So, what else, sensor?, etc. could make this happen? Your thoughts? Anyone? Beuller? Silver7? Nail Grease? PlPlPl, etc/?

 

[The Todd]

Air, fuel and fire. If you are pretty sure it's not the fuel check the fire. More than once people have spent a lot of time chasing down fueling issues that were spark related. Start at the plugs and work forward.

Are you getting any misfire codes? Does it feel like it's down a cylinder? Could try swapping wires or plugs to rule them out. Start at the plugs and work back.

While I agree with you, you may have missed the parts where I said when it won't start that spraying carb cleaner in the Throttle body and it fires right up, then dies again. It does run mostly, but sometimes intermittent. When it doesn't run, it reads zero on the fuel pressure gauge.
When it does run it reads a steady 48#'s. Well w/in spec.

No codes at all!

Yup....I have an old truck. Its 1995 vintage. Start with the plugs. I'm a little OCD about them and remove one at a time. Check or replace and regap....then restart the truck. Then move on to the next one. Spark plugs, Leads, Dizzy, rotor......Amazing how a refresh with quality parts makes a difference. I don't get parts from RA any more. They never stood the test of time or mileage.

Thanks, but see above.

Poor/intermittent electrical connection to the fuel pump?

Yep, It's hard to get to look at the top of the fuel tank where the pump is located/drops down into the tank. I'm still working on that LOL. Maybe a rodent chewed some wires? But now it intermittently runs.
Can't take it anywhere now really- don't want to be stuck and call AAA.

If you can spray either in the throttle and it fires, that proves a fuel problem. Does it have an inline fuel filter?

No inline fuel filter. When it was acting up, it finally started and ran a few days ago and I filled the tank, thinking maybe the bottom 1/2 of the filter sock is clogged?


Thank you all for your replies!

Oh, and btw- this 4.7 SOHC V8 has Coil on Plug ignition- no rotor; and
individual injectors for each cylinder.
I just checked yesterday- no stored codes- no Check engine lights either!

Is there any way some other sensor keeps the fuel pump from working sometimes?

 

[The Todd]

Have you poked around the wiring for the fuel pump with a meter? I'd be interested to know while you are getting 0 PSI what voltage you are seeing at the relay, fuse, connector at the pump, etc. I know you said the pump is difficult to get to but it sounds like it could be a loose connection or if you are having another sensor that is cutting power to the pump you should be able to trace back to that through the wiring.

If only I were food enough to do things like this! It is great advice! I'll see what my neighbor can help with when he gets back in town in a few days.

Any ecu controlling the engine? I had one ecu that intermittently after rain or high humidity refused to run. Replacing the ecu solved the problem.

2001- yep, it has an ECU, I suppose I could try that.

It's hard to do much when the value of said truck is under $1000, and it needs new rubber soon too LOL

 

[The Todd]

Sounds like an intermittent fuel pump ground, you did state the truck is rusty. Does the fuel gauge also act strangely?

lately, it has shown empty when it gets down to 1/2 a tank. When I cycle the key a few times, it then reads at least 1/2 full then.
So I guess, yes it has.

 

[The Todd]

@The Todd forgot to ask if letting the truck sit like this all winter long could have contributed to the problem.

View attachment 150056

That's not snow.
This was some snow LOL

 

[The Todd]

I'll try and get under there and look at/check the wires, etc. It's really hard because it's on top of the fuel tank, and that is strapped by rusted straps to the bottom of the truck LOL.
Imma wait till my neighbor is back in town in a few days- he'll know how to chase it with a voltmeter too LOL.

 

[The Todd]

Update:
Late one at that.

So a few weeks ago I completed the Fuel pump Change. I did it in stages.
I actually got it to start, and drove it into my garage! Put the left side and rear on some jack stands too. This made it easier in my garage than on the street.

It was a BEEEEATCh too. Things all rusty, etc.
I managed to get the bolts holding the straps off! Propbem was though, the whole stud came out of the keeper thing in the frame. I managed to 'build' some more using some studs and nuts from my local ACE hardware!

The inside of the gas tank looked really clean too!

Got it back in, started right up!

I've driven it several times now, no problems. Oh I love the manual tranny!

I have the bed cover/shell off and will be putting my motorcycle in the back and driving it to a 2 day Track Day event this weekend!

 

[The Todd]

As planned,
Last weekend I did a 2 day Track Day on my GSX-R1000 at a track about 90 minutes away!
But instead of renting the Uhaul M/C trailer and sleeping in the Pilot with the 2nd and 3rd row down,
I hauled it in my truck, and slept in the bed with my canopy over the bed (instead of across the back seat).
It was an awesome weekend!
I even got my 'bump' to Intermediate group on my 3rd track day!

I did 251.6 track only miles last weekend! Hitting just over 145mph on the short front straight.

My tires at the end of the weekend. Bridgestone S21's. (If only I'd would have had some Sumitomo's!)

There's 259K miles on the Dakota! Love the 4.7 L V8, and the manual transmission!

It's a truck (pick up).

This is the bed when I got home in my garage. I had things in the back seat area of the cab too.

This is the same bike arriving early for the bike night last Thursday at the Iron Horse Hotel- Milwaukee.