I think I have this figured out. I did some more searching and come up with quite a few threads around the interweb about fuel pumps not working and 6.7V output. I eventually found that This is done by the PCM (ECU), it gives the relay/fuel pump 12V initially for 2 seconds then once pressure is up it drops to 6.7 until motor is running. Because most can't run the motor without the fuel pump, and people do a test to find 6.7V, they come to the conclusion that something is faulty with the relay or that side of the electrical components.

So that's the theory I have. It appears that when the fuel pump in replaced, the issue is solved. But I couldn't find anywhere about people going back and testing it again to see if this situation still happens. People appear to just get it going again and never return to the thread.

I've pulled the fuel pump, removed the pump itself from the assembly and tested it directly, it is indeed dead.

Good thing too with the alloy tray, I was able to remove the pump without dropping the tank and without removing the tray!!

Then off I went to Ford to see if they had one. We live in a very little town so no they didn't keep anything in stock. Nor did anyone else have anything remotely close. I rang around, first price was $350!! Second was $280, a tad better. But I figured, surely this is a generic pump used in a wide range of cars.
There was nothing on Ebay Aus. Ebay US had a few options, much better at around $150 for the new assembly. No one seems to list just the pump, only the lower assembly, the pump inside the plastic housing and etc.

I found the Walbro webiste, they make the pump, and looked around. Found they have the pump itself with rubbers and new filter for $83.23 on special for $44.99. Heaps better! But I couldn't see if they posted to Aus.

1990 Ford F-150 XL Standard Cab Pickup 2-Door 5.8L 351Cu. In. V8 GAS OHV Naturally Aspirated OEM Fuel Pump Replacement

I then used their part number, TU200, and hit up Ebay US again. Straight up I found the pump for just under $50 plus $17 post to Aus. Awesome!! So much better then $350.

But then I still thought it would be possible for this part number to be used in other vehicles. Kept searching and found from the same seller, the TU200 pump, for $16 plus $17 post to Aus!!!!

eBay Australia: Buy new & used fashion, electronics & home d

Cost me $33 for a replacement, way way better then $350. Worth the couple of hours searching it for me to find it!!!!

 

Great result Ash! That's a great success story. Thanks for sharing!

Better get some petrol in the tank before you fit the new pump - or maybe a manual cut-off switch for the power feed to the pump...

 

No worries at all! Hopefully it works and if it all comes together, maybe when someone else searches in the future they may find my post.

Ideally, this style of LPG system should shut down the petrol pump when switched to LPG. The injection system which I'm putting on works with the petrol system and manages it itself so you have to have petrol in the tank at all times. It'll start on petrol until it come sup to temp and will also squirt in a bit of petrol along with the LPG in the higher rev range if it feels it needs a bit of a boost.

It should only be about a week until this new pump arrives. I've just put the cover of the fuel pump back on the tank to seal it off again. Once it's up and running, I can start with the LPG injection. Can't wait to try this beast out without the bottleneck in the air intake. It already goes quite well, should be just that much better again!

 

Sherlok Holmes would be proud. Great bit of work m8

 

Cheers Brian!!

 

bugger, we've just got into Darwin (and are about to leave again) and just stumbled in here - had I known earlier I could've sent you either a Walbro GSS322 pump or a standard pump that I was going to put in before the Walbro went in... nothing wrong with it, I just upgraded to a bigger bosch pump getting ready for a new engine/turbo install.

spewing!

 

What a bugger!! Ain't that always the way. It's all good though, enjoy your trip and maybe you could help next time. Cheers!!

Oh, and what new engine combo are you installing? Sounds insane!

 

Hey Ash,
I just subscribed to keep up with this project of yours. Don't forget to post some pic's of your SPI stuff here too. Maybe we could drum up some more business for Barry.

 

Hey Grubbworm, I will be sure to post up my progress. I'll hopefully have a few updates this week with the fuel pump and possibly the LPG swap. The pump turned up last week but I've got my plate full at the moment with work so we'll see how I go.

Still reading through your thread. Had a big day/night yesterday and was quite crook today. Am liking some of the small touches you've added, I wasn't even aware of some like the under bonnet tool box and light. Well done!

 

Put my truck to work for the first time on Friday. Got rid of one car on the way down and picked up another. About 200k's round trip. I have to say I was impressed, loads of torque and pulling it was no effort to the big girl. Taking off at some sets of lights did result in some tyre squealing and lots of turning heads, needs an LSD centre or something along those lines. But other then that she never missed a beat. Got to say I like my new truck!

 

Excellent stuff Ash. Glad its working out for ya bud. Whats the deal with the AU. Another project ??

 

Just a bit of a hobby and also makes a little pocket money to spend on my cars. I'll pick up a damaged car here and there for some bits I want and sell the rest. This one is a stat write-off, had a hit in the front left. But it is a 5 speed car so a few good bits included.

It's the one bad thing with having a big shed, I just fill it with more cars and more car parts!!

 

Ah the big shed thats were I will be going when I die. The big shed in the sky.

 

The engine combo is for my Fairmont. Have an AU motor sitting, waiting for forged pistons/rods, new oil pump, head work with better valves, guides, springs etc, will be swapping exhaust manifolds so I can shove a bigger turbo under the bonnet, and a more efficient inlet plenum as well. May or may not do water/meth injection, or maybe even nitrous into the front-mount to cool the air, depends entirely on inlet temps. Then will be getting a trans-braked T400 (shhhhhhhh..... I know.) and cutting a 9" centre into a spare Borgie diff that came out of it a while ago. It will retain all it's Fairmont goodies too - what's the point of reeling off 10's and lower if you can't enjoy driving it every day as well??

Before I build that bad boy though, I have to finish screwing together a fresh 351C for the truck. That's copping fresh gaskets etc with a nice and mild Lunati cam/valve springs/retainers/collets and a 760 holley. I'll have to locate and update my progress thread... because I also have a rad support panel to fix up and install, along with an ali radiator and EL thermo fans..... and it all needs to be in and running before I go back to work next time (late june)...

Anyway now that I've finished hi-jacking your thread with my junk, you can have it back again!

Cheers
Jais

 

That sounds like it'll be insane. I thought you meant you were doing a turbo conversion on your truck, silly me. That sure would be something different.
I've never had much involvement really with turbos, next to none actually. A lot of the stuff you mentioned is over my head of understanding. I can see by your collection you sure have some ponies tucked away.

Just put this new fuel pump in and she fired straight up. I was worried about the injectors being gummed up but it is running smoother then it does on LPG. Goes better too!! Doesn't do the typical LPG mixer style of thing and run out of RPM's around 4k. I can see now this thing is going to go quite well with the mixers removed from the intake and the LPG injection installed.
Now that the fuel is operational, I can now try to find the time to install the LPG set-up. Spare time and me are not close friends and I have a 69 Mustang that needs some of that little spare time as well. I'll get there, slowly.