Caver Dave

After spending last weekend finally changing the oil (Wix/Rotella T), changing the rear diff oil (it was BAD!) and washing the old girl up (was filthy from sitting under the trees)... I agreed to haul a car (1 owner complete '65 Barracuda pics coming!) for a bud's dad on Friday. Many thanks for all the tips, tricks, & specs which allowed the fluid changes to go without a hitch!

Loaded up Friday afternoon and left out to meet Mike. I found it would pull the empty trailer in OD, while keeping the tranny temps in check (dropped into 3rd on the steeper grades). Everything felt good, was running great! After about 45 minutes of cruising (2100-2700 rpms) I got to the exit... stopped at the bottom & puff, it idled way down and shut off! Spun over freely, but wouldn't start... "sounded" like no fuel. I checked the intake bleeder and there was very little fuel coming out. Fuel filter is only 3000miles old, so on a hunch, checked the fuel filler cap... HUGE vacuum (took 20-30 seconds to finish whooshing) built in the tank! Figuring my obviously NON-vented cap must be the cause, I left it loose, cracked the bleeder again & got fuel. Then cracked the rear injector lines and got fuel. Spun it over and she came back to life! Yaa! Temp was about 95*, I was happy to get off the exit and get some air moving across my body!

Proceeded thru town, keeping the revs up (1st-2nd gears) and arrived at the pickup point. Left it idling to cool down a little more and found the water separator dribbling... fiddled with it and got the drips to stop & shut it off. After 30 minutes, it easily fired up to move down the hill in prep to load the car (non-running at this point).

We got the car loaded after 90 minutes (was HOT, so we went very slowly) and drove a few miles towards the highway to eat. After chow, we filled up and took off down the highway. With an approx. 5500# load (car = 3k#, trailer = 2200#, tools/spares/fluids in bed = 300#) it easily held 65mph in 3rd & the tranny stayed under 180* (sender in output line). I bumped it into OD on the downhill runs & pulled a few grades, keeping an eye on the tranny temp... along we went. Pyro never went above 1000*-1050*, even on matted 70mph+ runs up the hills. After about 45 minutes, our "chase truck" driver noticed a loose strap letting the rear bumper bounce dangerously close to the trailer ramp, so we pulled over to tighten it. Just as the truck came to a stop... it cut off again! Since the cap was LOOSE this time, I knew it couldn't be a vacuum situation, but acted just like the first time. Ended up bleeding the rear inj. again and she fired back up after 10 minutes had elapsed.

Since this had me worrying (was it gonna take a total dive?), we ran non-stop on to Greenville... when we got off the highway, I bumped it up to N, which let it idle up (still 900rpm) and it ran fine all the way to Mike's house. But then it shut off as soon as we came to stop!

Got the car unloaded & topped the tank off. I ended up doing the return leg straight though (NO stops) and got it cooled down pretty well on the 3 miles between the highway & my house. When I pulled into the driveway, it was 0130 (family asleep) & the pyro was reading 300*, so I just shut it off.

IIRC, someone just had this issue and believe it was diagnosed as the IP (or some component in the IP)? I'd hoped to have a fuel pressure gauge installed before now, as I've thought there was a fueling issue for sometime (based on lack of smoke & pyro numbers), but that's still not done.

Keep in mind that since the fuel screw twisting, she's always idled up about 850rpm (still haven't indexed the throttle ) in gear, but each time it died it was down around 500rpm in gear.

1) Do these symptoms sound familiar to anyone?

2) Am I correct that there should NOT have been that much vacuum in the tank & it needs a vented cap?

3) At one of the "stops" bleeding the inj. lines, I also noticed that the fan clutch felt a bit "loose". As hot as the outside & underhood temps were, I figured the clutch would have been locked up near solid? Engine temp never went higher than dead middle of the factory gauge (yes, I know it needs a *real* gauge!) and never overheated. Will the fan clutch ever lock up completely? Or is mine porked?

wannadiesel

Did you try pushing the accelerator when trying to start it hot?

You should not have a vacuum in the tank sounds like the vent is plugged up.

To diagnose a worn out IP, next time it doesn't want to start pour a 5 gallon bucket of water over the back end of the pump and see if it lights right off.

Check closely for an air leak between the pump and the tank. It would be enlightening to know what the fuel pressure is when the truck dies.

Fan clutch sounds pretty iffy to me. Touch the front of the clutch and see if you get gooey yuck on your fingers.

bgilbert

Excellent question. I just about bet if you tried starting the truck right, after it died, with the accelerator pedal either half or all the way down it would start right back up.

Sounds like a worn out injection pump. Low low idle when hot like that is a symptom.

Caver Dave

Yes, I tried both 1/2 & full throttle after it shut off.

Is there a vent line for the tank itself or does the cap provide that function?

I'd heard of cooling the pump with water from the Ford camp, wasn't sure it was applicable to the VE though.

As the PO(s) added the 80gal bed tank, Pollack & accompanying sketchy lines, it's likely to be sucking air... has taken 1/2 throttle to start for the past 6 months. Maybe I'll eliminate the Pollack and check it. I'm planning to plumb the FP gauge this week if all goes well.

No goo on the fan clutch, but it isn't much harder to push hot than it is cold... OTOH, it doesn't appear to be causing any issues...

wannadiesel

Dingdingdingding!!! We have a winner!

Some trucks have an open port on top of the fuel sender. I'd just scare up a vented cap or vent the one you have.

The fan clutch has to be really hot to lock up, you will often have to block the grille with cardboard and let the truck idle with the A/C on to make it lock. They aren't cheap, so it's worth the time to diagnose it.

Caver Dave

So, Dr. Wanna... what correlation does the potential to suck air bring towards diagnosing the low idle when hot? Or does it?

Pretty sure I can make the existing cap "vent", but will check to see if I can locate a separate tank vent first.

Based on the engine temps staying well in check, I think the fan clutch is fine. It just felt a bit "loose" for what I figured it'd be in the heat. I run a flex fan on the Jeep, so I have little to compare it to...

wannadiesel

It's sucking air and dying, not idling low. While the rpm/fuel flow is up it's tolerating the aerated fuel.

Caver Dave

Well, I checked for any apparent leaks in the suction side and found nothing. There's a severe "throb" in the suction line also

I finally got the gauge (Mr.Gasket 0-15# cheapy) and the adapter banjo bolt from Genos installed. As time was running out (have to help my wife and darkness), I dropped it in place at the FIRST banjo (inlet from LP), as I wanted to keep the bleeder for now... just in case. I fired it up to allow the line to bleed (assuming air in the line would not give me a correct reading) and snugged everything up (no apparent leaks)...

I realize that this will only tell me the pressure between the LP & filter (I'll move post-filter later), BUT... I'm only getting 2.5# at idle & <2# any RPM higher than that!


Does that mean the LP is definitely DEAD? I recall BK saying his would run (albeit not too well) with a DOA LP. Mine will run, but just feels "weak". There's a severe "throb" in the suction line, if that adds to the diagnosis?

Caver Dave

OK, maybe some additional info would help diagnosis?

I found numerous diaphragm LP pressure references that ranged from 3#-7# at idle... I assumed these were post filter.

I fired it up again before heading to work. Actual pressure on the gauge (PRE-FILTER) during idle is LESS THAN 2.5#, around 2.25#, and ANY pedal activity (slow rolls or hard blips) sinks the needle down towards the ZERO mark. There is NO pulsation on the gauge at all... nice fluid movement.

There is however a strong pulsation/throb in the suction side of the LP. Is this normal? I found a post from BK about a check valve in the the LP hanging open that allowed the fuel to run back to the tank. It stands to reason that if this valve were "bad" it could cause the pulsation in the suction line *AND* not allow the pump to make any more pressure than it's making.

Anyone?

HappyCamper

Sent a PM...

wannadiesel

Pump is dead or there's a restriction in the suction side.

Caver Dave

Thanks Wanna!

I ran it for about 15 minutes (mostly idling) again this evening while I re-bled the gauge line (since air compresses differently than #2). This actually *dropped* the pressure to below 2# at idle. 1500RPM pulled it within the needles width of zero... still

Think I'll put in the barbs I bought to bypass the Pollack... on the chance the Pollack *IS* the obstruction (and possible air leak!), before I fire into swapping the pump. Will let you know if there's any change

Thanks again brothers!

Caver Dave

OK, between the office, 2 side businesses, building a "leaf vac" for the mower, & doing the yard work today ...

I managed to bypass the Pollack valve with 2- 3/8" brass barb-barb fittings and put a twist on all the clamps. Appears the PO cut the "nylon"(?) tube from the tank where it met the Pollack and coupled everything together with hose. I inspected the hose for dryrot, but didn't find anything alarming.

Upon firing it up, the pressure jumped to about 3# at idle and wouldn't go lower than 1.75# WOT. Looks like the Pollack was restricting it somewhat. There is still a strong pulsation in the suction line... possible check valve issue in the LP???? Startups still require a tap on the accel pedal to fire

While I'm sure the Pollack was causing some of it, the low fuel pressure doesn't look good. I'd love to drop a industrial piston LP in, but funds are tight... Will probably install a new diaphragm LP, find the correct fitting to eliminate the section of "nylon" tube/quick disconnect at the LP, and hope than does something more for the fuel pressure.

If not, looks l may be dropping the tank to see if somethings (what's) up with the supply line/pickup, will likely do the same thing BC847 did... ain't gonna drop the tank but ONCE!

If anything jumps out at you (Wanna? ), feel free to chime in!

Rampage1967

Mine had the filter on the bottom of the Pickup module plugged solid.

There are also a couple restrictions built into the pickup unit .. I drilled mine out & replaced plastic "hose" with 3/8 rubber one.

The truck starts & runs much better now.

Caver Dave

Thanks for the reply brother!

What was it "plugged" with? Some type of "algae", organic matter, or general filth?

Also, what led you to pulling the tank? NO flow? Little flow? Did you swap the LP during diagnosis, prior to pulling the tank?

I know you can add a vac gauge in the line to diagnose a restriction, just wasn't sure how reliable that was. If a decent troubleshooting method, I'll do that BEFORE I swap the LP...