Hi everyone. I have been a reader for a couple years, but never posted before. I really appreciate the information I have been able to learn here.

Currently I have 1995 7.3 263k Kms (164k Miles) that has some fuel issues. I have done a ton of reading this last couple days, and have learned lots.

Basic history: I have owned this truck since 1998, it has been very reliable.
Over the past year or so, Ive noticed a bit of a decline on power... nothing drastic, just enough you notice she aint what she used to be...
This last couple months there has been a small but growing fuel spot under it in the morning.

Yes, its been on my to-do list, but...

Anyway, last week I had a couple times it failed to start... extended cranking. Let sit a bit, 'lil snort of ether (ya, I know but that's a whole different story) and she'ld light up, but was not "crisp", kinda loaffy if you know what i mean. Once it was running it was fine...

Oil had not been changed in a bit, so new oil & filter and it started up, much better, but the sporadic no-start issue is still there.

With an obvious fuel drip, figured it was the pump or plumbing, so dug into it yesterday and pulled the whole mess out. Given that the fuel bowl and pump are so crowded and prone to leaks, I was contemplating doing the remote filter mod. I have read lots of threads on this, and the one answer I haven't seen discussed is weather removing the fuel heater is a big deal. When I tore mine out, the wire was disconnected, so mine wasn't working anyway, just wondering what others think... Is it a big deal, does it ever really do much? I live in southern BC, so we get a couple cold months, essentially Spokane's weather.

I tested fuel pressure before tear-down at schraeder connection: 47psi cranking, 52 at idle, but still had no start once in a while. before teardown, there was the odd drip below banjo, but so much gunk it was impossible to tell if it was from banjo or just rolling back from somewhere else. Once out, banjo was not super tight, but other spots were weeping too, but not enough IMO to cause a no-start.

Im heading into the city today and will get parts to test the HPOP.

With the PITA it is to get the turbo & other stuff out, Im kinda leaning towards a remote filter (even if I leave pump in the stock location, just 'cus if I have to deal with the HPOP or IPR, (or anything else under there) is would be waaaaay easier than pulling everything out again.

Plus I need to spend the money to rebuild bowl anyway, maybe should put that towards the remote setup. Are there ANY advantages to keeping the stock fuel-bowl cw heater?

Any comments?

Thanks
Tim

 

Hi Tim. Welcome to the sight even though you've been watching for a while. There's nothing quite like getting in on the action, eh?

I'll give you my opinion for what it's worth (which shouldn't be much). For a stock truck the main improvement you are going to see by doing an e-fuel setup is that you are cleaning up the valley. That's it. Yes it might start a bit quicker (maybe, but I'm not sure that's the cause of your starting issue). Yes, it may idle a little smoother (probably not, it's a 7.3). It may give you a moderate seat of the pants power gain (again, probably not though). What it will definitely do though is clean out the valley.

That being said, you're replacing a mechanical pump with an electric pump. Mechanical pumps fail, but when they do they leak. When electric pumps fail they leave you stranded somewhere. With stock injectors the mechanical pump is sufficient for fuel flow needs. But the stock system is a pain to work on and can be a leaky pain in the butt. That being said, rebuilding the bowl with all new o-rings is cheap (like $20 cheap) and a new (stock) mechanical pump costs a lot less than a new electric pump. Rebuilding it is definitely the cheaper option as the more inexpensive e-fuel option cost about $300-$350. But then again you're absolutely right that the mess is still all down in the valley then. You have to decide what it's worth to you to get rid of it.

Now if you have any plans to upgrade to a bigger set of injectors down the road, then the e-fuel is definitely the way to go.

And as for the heater, I have had no problem whatsoever running my truck in the single digits (Fahrenheit) without the heater in the bowl. Supposedly it was a much bigger deal before the fuel standards were tightened. We have better fuel now (in that regard) and it seems to resist gelling in cold temperatures better than the old stuff. At least that's the case in the states. I'm not sure on the Canadian standards.

Hopefully that helps more than just muddying the waters...

 

Thanks DIYMechanic...

I agree that mostly what i would accomplish is tidying up the valley.... just a work truck, no plans to beef up injectors. I was actually just considering replacing the filterbowl and leaving the stock pump. Doesnt totally clean it out, but just mulling weather its a step in the right direction.

Im not totally convinced the pump is toast, I might have other issues as well, have to look closely at the IPR and related stuff....

Putting new pump in regardless, and figured I might as well to injector o rings while its all opened up.

 

Hi...

Hooked up two gauges to the lines from the HPOP, with IPR unplugged no pressure, with it plugged in, it will make 18 / 1900psi on each line.
I unplugged the ICP and readings were the same.

My forum reading seemed to indicate that I should see about 3800 deadheaded, is that accurate, at cranking speeds? Or is ~<2k like I'm seeing ok?

There is oil in the connection cup for the ICP, so Im assuming that the pricey 'lil beggar is toast...

With the ICP unplugged, should I be seeing higher pressures? Is it likely (or possible) that the IPR is weak, or am I looking at a new HPOP?

Thanks
Tim

 

I believe if I'm not mistaking that the icp needs to see 500 psi before the injectors will fire. Have you tried unplugging it and them trying to start it?

 

I believe you are right, madMatador78

The truck was running, as per my OP, I have now pulled turbo, lift pump and fuel bowl out, as there were some leaks. The original issue was sporadic no-start, as well as not being as crisp as it should be.

Original testing showed ~50psi fuel... I was unsure if fuel delivery was ok, or if no-start was coming from HPO related issues. When I tore it apart, I see oil in the ICP cup, so ...thats not a good sign... Im wondering if the roughly 2000 psi Im seeing is normal for cranking with gauges deadheaded, or if not, is there a way to test / inspect the IPR to see if its leaking or if the pump itself is dying.

Tim

 

I think what you're seeing on the HPOP is fine. The PCM does, indeed need to see 500 PSI cranking to fire the injectors. Your next test if you still have a no-start is to put the gauges on the head and make sure you're getting 500 PSI with the heads hooked up. Blown injector o-rings can allow enough oil to bypass that the HPOP can have a hard time building pressure.

I also agree that you need to either try to start it with the ICP unplugged or replace the ICP. Typically, if there is oil in the connector the ICP is shot. Since it's an intermittent problem, I'm guessing it is the ICP.

 

Thanks Guys...

I agree, I just moved the gauges to the heads, and have 1000 to 1100 on each side consistently with the ICP connected or not...

I had unplugged the ICP when this all began, and it did start, but the problem was not consistent, TBH, I cant remember if the no-start only came back after it was reconnected.

I will get an ICP with the rest of the parts and see how it goes, if I still have the issues, Im assuming the IPR would be the next culprit? Is it worth pulling it and cleaning it out? some of the ones for sale talk about a screen, is there something to clean out?

Where would you recommend online to get parts?

Tim

 

I think your HPOP is fine - usually a bad hpop shows up when the truck doesn't like to start when it's already hot.

+1 What DIYMechanic said on the electric vs mechanical fuel pump. Mechanical pump really not that hard to chagne. I've done it in 3.5 hours start to finish and I'm not that good at it...

Same for the heater. I'm just north of Detroit so we get about 3 months of potential 0F or less weather. Main issue with the fuel heater is it typically shorts out and takes out fuse #22, which happens to also feed the PCM. Quick solution which often gets implemented when truck blows that fuse in sub zero weather is wire cutters to the line at the bowl feeding that heater element. I have a block heater for overnight and have never had an issue with the fuel heater gone.

Rory

 

If you have that much ICP, the IPR isn't the issue. Try unplugging the ICP and see if it runs.

For Parts you need look no further than Riffraff Diesel Performance. The prices are great and the customer service can't be beat.

 

I appreciate the input everyone.

I think I likely have a couple issues that all came together. Definite fuel leaks, possible weak lift pump, and questionable ICP. will order parts for that and let you know how it goes...

Tim

 

Sub'd...I had similar questions about considering E fuel. I am also interested to see how this turns out.

 

Wow! I guess you guys did teach me something after all! Good info to know.

 

While I have this all apart...

I do plan on leaving the truck essentially stock in terms of HP gains. Really all I'm after is an increase in daily driveability, and possible overcome the slight drop in power I mentioned in OP.

There is a few threads on shimming the regulator on the side of the fuel bowl, or inserting a bb to boost pressure to the rails. Simple question, good idea / bad idea? Who's had what experience with it. Just stock injectors, now and forever...

I also noticed the EBP/EPR looks like she might be weeping a wee bit. not wet, but dirty. Some threads about rebuilding, vs tossing, vs modding and also use as exhaust brake. Any comments? I had an old Mercedes with an exhaust brake, sorta worked... unless it struck on in traffic.
I do live in the mountains, but TBH i've never noticed a huge issue using low gears (even with the AOD) slowing me down, just wondered if its a worthwhile mod while its ripped apart. Any long-term users of it here?

Tim

 

Got my box of goodies from Riffraff yesterday, Kudos to them, everything I asked for, and ahead of schedule.

Found part of the problem:
cleaned it all out and put new o-rings in...


Also, found the bottom pass side turbo flange nut a pig, I know there's lots of different ideas, here's what i did, took about 15 min, and was easier on my knuckles...