I should state this for anyone who comes across this in a search trying to fix their truck.

If you have no fuel and are showing signs of a voltage drop of 6.7V to the fuel pump. This is NOT the problem. I found several places in my search for an answer where people thought this was the case. It is NOT. The ECU sends 12V to the fuel pump when the ignition is turned to ON, shortly after the fuel pump primes, the ECU drops the 12V to 6.7V to stop the fuel pump operation. Once the motor starts the ECU then sends 12V again to the pump while engine is operating.
If your fuel pump is burnt out, as mine was, it appears the fuel pump is only getting 6.7V as the ECU thinks it has primed and is waiting for the engine to start. It wont get 12V until the engine starts but with no fuel pump, this wont happen hence why it stays at 6.7V and why people think this is the issue.

I replaced my burnt out pump with this aftermarket version of a Walbro TU200, also known by these variations:

WALBRO REF # TU-200 / TU200
AC DELCO REF # 43-103 / 43103
AIRTEX REF # E2059MN

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

Hit the starter and off I went straight away.

I hope this description is clear enough and will come up in anyone's search for an answer. It was quite straight forward once I discovered the problem, that 6.7V easily sends you on the wrong track.

 

Been a while but I've been too busy out and about in my truck. I love this thing!
Winter is over now but it did quite a few loads of this



This load is for next season. I had to drive 120k's with this. The right hand rear tyre was touching the under side of the tray every so often. There was a lot of wood there. I estimate about 3 good box trailer loads. Other then the tyre scraping, it didn't phase her. Steering was a bit floaty though, all good fun.



Even 6m lengths of steel don't look long on her



The kids all love it too.



Everything was going great until about 2 weeks ago I heard a loud pop and had a heap of smoke in the cabin. I quickly found the little LPG controller was now toast. Just down the road no more LPG, petrol only. OUCH! On the flipside though, it did force me to pull my finger out and start the LPG injection swap.

Out came the intake to drill and tap in the brass nozzles for the LPG hoses.



When I put the intake in I also put in a set of injectors from a couple of 6cyl Falcons. I was under the impression that these were 19's as the standard 351W's are. I'll come back to this.



New converter went in place of the old but it is smaller in size with one less hose



The injector rails mounted and hosed up. I had to No.1-4 cylinder hoses on the R/H bank through the centre of the plenum and because of this the shortest I could make them was 350mm. All 8 have to be the same length, so what ever the hardest one to reach length is, that's what they all have to be. Problem with this is the system says they are to be 300mm max. But I could only do what I can do.





All together



After it all went back in, the fun and games began and they are still going! First after getting it all together, I had a air leak causing it to rev like crazy. Found the rear harness had a metal tab that was pinching between the intake and plenum. A minute or two and that was fixed.
From there the engine was running like ****. As if it was running on 6-7 pots only. Took me ages to figure it out. I tried everything I could think of, timing, dead plug, dead lead etc etc. Then I thought maybe those new injectors were not compatible as I thought. A bit of researching and I couldn't find a 100% answer to say that they were 19lbs as I thought they were. So... out it all came again and put the original orange tops back in.

All back together again, no change.

A lot more researching and head scratching I eventually discovered that I had the two injector wires on No.8 in the new piggy backed LPG wiring back to front. So, you guessed it, I had to take it all back out again to figure that out. Getting pretty quick at this by now!

Swapped the wires and she fired straight up as it should. BEAUTIFUL! A bit of a dance around the shed, I was happy again and no longer wanting to burn the ****ing lot.

Now I attempted to calibrate the LPG mapping but wasn't having much luck. The truck was just keeping too cool with the large radiator and thermo fans. That day was over so I left it. Came back the following day to find a leaky injector, it wasn't sealing between the rail and injector but it was one under the plenum. So out it all came again.

Found two damaged o-rings. Swapped them, put it all back together, AGAIN! No more leak.

Continued on the lap top to calibrate it but trying to get the temp right wasn't easy. Then the temp sensor on the LPG converter started dropping in and out. I found out this was common. Tried a few tricks, had a little bit of luck to get it to hold but midway though an auto-calibrate it would drop out. This means you have to start all over again. Took me a day or so to find where I could get a replacement. Got one on the way but it was going to take 2-3 days.

Got the new temp sensor installed. Have also now figured out how to get the temp to stay above 90 degrees Celsius to keep the auto-calibrate happy. The truck has a thermo fan override switched installed by someone next to the steering column. If I disconnect the thermo fan temp sensor and use the override switch, I found I need to keep the temp needle floating over the "A" on the temp gauge to keep it happy. Pain in the **** but that's what I had to do to stay above 90 degrees and below boiling point.

After many many tries at auto-calibrate, some manual fiddling of the maps, I can get it to idle and rev when parked but when driving, she just isn't happy.
I've tried to leave out the O2 sensor on the LPG system, apparently it isn't absolutely necessary, as I'm not 100% sure what voltage range it runs in and if it is working 100% to as it should. I think it should be in the 0-1V range but the readings are bumping over 1V and I don't think this is how it should be. Until I find out for certain, I'll keep attempting to calibrate without the O2 sensor.

The only other thing I can think of at this point is those hoses from the inlet manifold to the injector rails that are 350mm long and should be 300mm max, they could be the problem. This afternoon I moved the R/H bank rail and hoses to try and make them shorter. I found that if I mount the rail to the right of the engine and pass the hoses under the plenum and above the rocker cover, I can get at least 80mm off the length taking them to 270mm. I just need to finish this off tomorrow and then try the calibrate again. Fingers crossed this is going to be the fix. I'm running out of ideas and my brain is hurting a great deal!

 

Yer Brain hurts M8? Mine hurts also from just reading this.

I got a 90 Dodge W250 that wont go over 40 MPH. Just coughs out. Me and every shop I can find has worked on it and cant fined the prob. It's been like that now for 10 years. And it's just a throttle body setup. I know Carbs but this electronic crap is way over my head.

I can't imagine trying to do what you are doing. You Da Man.

 

Nice write up m8 and a good bit of detective work. I feel ya pain bruva. keep us posted and reps for the pics.

 

Thanks Arctic and Chunder, appreciate it!

Nutted it out a bit more today. I was pretty shot at the end of the day, done my head in a bit more.
I spent about a hour this morning remounting the R/H rail to shorten the hoses. Worked out pretty sweet. I made the bracket larger then needed to also act as a heat shield from the exhaust manifold. I think it may be border line in regards to the installation requirement to not have one but it wont hurt at all to keep it cooler and protect it.





I spent the next two hours trying to calibrate it, no luck All I've done is use a lot of fuel, get a sweat and a sore leg from holding the throttle in one place. Walked away from it for a while to think a bit more.

My wife's car has the same system, so I plugged the laptop into it to compare. The figures are way different and I managed to get it to calibrate within a minute. So nothing wrong with the software or set-up.

Fiddled a bit more with the maps on the truck manually and spent more time on Google. All I can come up with is possibly the nozzle sizes in the injectors are too big and its throwing the maps out trying to lean it out to compensate. I have a smaller set of nozzles, similar to carby jets, I'll try them out tomorrow or Monday. Only issue now is I'm getting low on LPG and the nearest place to get some is a 150k round trip.

 

Pretty much got this sorted now. FINALLY!! The problem ended up being a setting on the LPG software. From what I could tell and what I was told by some LPG gurus, the truck was batch fire injection. Even though it was wired in two halves it was still batch fire or what some referred to as half batch. So I never thought of trying anything other then that. Well, I had run out of all ideas so I tried the sequential injection setting and off she went, ran sweet! Not sure at all why this is the case but that is what works.
I still have some fine tuning to do, I take the lap top out most times I go for a drive. I've done about 1000k's in it now and while the tune is getting better, the fuel consumption in my opinion sucks. So still more trial and error to play with. I'll get there, at least I'm on the right path now.

Got a question though, the power steering box in these RHD trucks, what do they use? Are they their own thing or the same as a LHD one? Mine has decided to leak a bit and I'd like to look into rebuilding it.

 

Glad to hear that you're further along the path to getting this sorted!

The 7.3 effies run 2 steering boxes - the one on the left side is the stock US box, with Ford Australia adding a manual box on the right side and a rod across to the left box.

You'll have to check your set up and see. The boxes themselves are renouned for leaking as they were, alledgedly - I don't know for sure, built without bearings, just holes milled though the housing that the steering shafts go through.

A decent machine shop should be able to sleeve it for you if this is the problem causing the leak.

 

Thanks SSSimon. I'll stick my head back under and have a better look at the set-up it has.

Appreciate the advice

 

Sorry for the slow reply, things have been busy and other things with the truck have taken priority.
Looks like it only has the single steering box but it's not dripping like it was. It needs to be done but not a priority at the moment

The truck was running like absolute crap. Found some dodgy leads, not even sure one was on and the plugs were cracked or worn. Swapped them out with new plugs, MSD leads, new and filter and just waiting on a new MSD cap and rotor. It was then running much better as you'd imagine.
Then it developed a bad exhaust leak, which I just now fixed. I swapped out the O2 sensor while I was under there and it now runs the smoothest and quietest it has since I've owned it.

I still can't get the LPG to run efficiently. I'm getting about 200km's to a tank which is not good. I was getting 300-350km's to a tank on the old venturi system. It does run well, pretty much the same as it does on petrol, it's just too thirsty. We'll have to wait and see if the replaced O2 sensor and fixed exhaust helps out, it should, but not sure how much. I still think the LPG ECU, fitted mostly to 2004 car models on, is not happy with the older truck half batch injection system. The truck runs a half batch system but the LPG ECU only has full batch (which it wont run on) or sequential (which it does run on). I think that maybe the LPG ECU is opening the LPG injectors more often then it should as it thinks it needs to open say 8 times a rotation where the half batch it should open in 2 groups of 4 a rotation. I could very well be wrong in saying that but I've tried so many combinations now I'm near giving up on it.

With all that being said, I can't find any way to select the suitable mode in the LPG ECU. So I want to ask, what do people do to convert the half batch injection to sequential on these trucks? I think they are replacing to a later MAF system but what parts exactly are the swapping out? I have a feeling the parts are going to be costly and if that's the case, I'm thinking about just going back to an older venturi LPG system unfortunately.

 

How are you coming along on that Mustang? Have you painted it yet> Please post some pictures of your progress on it too.

 

Unfortunately, Grubbworm, I haven't touched it for months. Must be at least 3-4 months since I've put a tool on it. Life really got hectic with looking after my kids and trying to make ends meet.
Really looking forward to getting back into it soon as life gets back to normal a bit. I need to get some more materials to finish off the end part of one of my sheds so I can enclose it to get the Mustang out there and sandblast it. Hopefully soon I'll have some pics to put up.

 

That's OK, I understand. I'm in the same boat with my truck. I've had to put everything on hold since around July, when my mother went in the hospital and nursing home. Then she passed away in November. So, I'm the one handling all the affairs. I guess I might be able to get back on it this spring. I absolutely have to get to the floorboards first. Good luck with your projects.

 

I'm truly sorry to hear about the loss of your mother, Grubbworm. When it comes to family, everything else comes second, projects can wait. My daughter needed surgery towards the end of last year so everything stopped until that was resolved. It's taking some time to get back on our feet but we always get there in the end. I hope when spring comes around you get some time to tinker with your truck. I am looking forward to some relaxing me time to just play around with my cars again for pleasure, not because they are broken.

 

Hi Ash, I second your thoughts above!

Great looking little tribe you have in the pic in post #62!

The projects are always there when there is time/funds to tinker - after all the important stuff is done.

 

Cheers, Simon The kids love to go for a ride in Dad's "bumpy" truck. My boy is always telling me to go fast. I just hit more bumps and he has a smile on his face the entire time.