wannadiesel

Yes, you can add a vacuum gauge. Cummins wants no more than 3.75" Hg, I'd want to see no more than half that.

Caver Dave

Thanks Wanna... I'll try this before swapping the pump. Shouldn't be too hard to drop a T/vac. gauge in place of the barbed connected I installed yesterday.

Does anyone running the OEM LP have the pulsation in the suction line? Just wondering if that might be another piece of the puzzle?

wannadiesel

Given the way the pump operates I'd be surprised if there wasn't a pulsation.

Rampage1967

The filter was plugged with 430,000 miles of assorted dirt.

I was having a problem with the truck pulling air & stalling out a low fuel levels. This got worse & worse over about a year untill it would do it at 1/2 tank. But it only did it at fairly high speeds.

The lift pump was fairly new.

BTW. I found it fairly easy to lift the bed off the truck instead of pulling the tank. (8 bolts, 2 hoses, 1 wire plug . . .lift with ratchet straps in stake pockets)

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tcs 91

had the same problem w mine. wouldn't keep running or idling coming off the freeway. wouldn't do it just driving around. get it up to 70 for awhile and it didn't want to idle. turned out to be an adjustment on the pump. did it for a long time before bret figured it out. seems the mech that did some adjusting on it made it run better but introduced another prob. know of one other truck w same prob. doesn't have to be anything serious. have a good pump guy look at the adj. something was going too far and around a pin inside and catching but i don't know enough abt the internals to tell you just what.

Caver Dave

Howdy brothers! After 7-8 months I'm back to the CTD! Many outside influences pulling/biding for time lately...

Anyway, I reviewed everything here and pulled the truck up closer to the garage. Confirmed the following:

- 2# at idle
- 0# off idle

Made a "bung" from shop rag (wrapped around blowpipe) and "threaded" into filler neck (surprisingly decent seal!). Best I can tell (regulator gauge is semi-pooched), I'm putting about 10#-15# on the the tank. Had a small leak on top of the tank, but a twist of the retaining ring stopped that. NO apparent leaks from lines or anything else off the tank (very small hiss near the blowpipe, but that's the coupling).

With pressure (10#-15#) applied and running:

- 4# at idle
- 3# off idle

If I disconnect the air while running, the pressures drop back to 2# & 0#. Hopefully, this might narrow down the issue(s) by indicating:
- Dead LP?
- Stopped sock/filter in tank?
- Still pointing to air/sucking leak?

wannadiesel

The first or second one. Does not seem like you have a leak, you would have had a puddle.

Caver Dave

Thanks for the reply Wanna... picking up a Carter-made pump from NAPA tomorrow (though the $95 does sting a bit!), unless there's a recommendation for an online/cheaper source?

Guess we'll see what happens with a new LP and go from there. I scoped out dropping the tank (pulling the bed is NOT an option due to PO installed GN plate) today... should be "fun" getting it up on stands far enough to slide out the bottom!

wannadiesel

I had good success with the el cheapo Delphi unit that usdieselparts.com sells. It put out 8 psi at idle, I ran it for a year before I switched to a piston pump.

Caver Dave

Are the Delphi units any better than the Airtex?

Caver Dave

I'll take that as a "loud" (but silent) NO! Carter LP inbound...

Caver Dave

WOOHOO! The NAPA (appears to be of Federal Mogul manufacture) LP went in tonight with ease. Fired her back up and after a 45 seconds of purging the air, have 8# at idle! I realize this isn't stellar compared to piston pumps, but much better than 2#...

Due to the fittings, paint, & gasket, I believe the old LP *may* have been the OEM (marked "AC Made In England")!

She ran at about 8# with various pressure with the throttle. Several times it increased with throttle, but mostly dove to 6# under load. Again, not stellar, but a far cry better than before. No real increase in smoke, but hopefully the new found fuel will aid in some better numbers. It obviously ran MUCH better on a short run for fuel and up the highway. EGTs are gonna be an issue now!

My thanks to all of you for wading thru this long running fertilizer post and offering your knowledge... CHEERS!

wannadiesel

Sounds like a healthy diaphragm lift pump.

Caver Dave

OK, the TBI install on the Moss is complete (just needs a bit more tuning) and the CTD is back to the top of the order!

Saturday, I gave her a quick scrubbing, replaced the BHAF, installed an Outwear filter and went for a drive to my buds to do some reloading. The fuel pressure gauge needs a snubber (pulsates wildly at times, others it's steady?), but it ran pretty dang good on the way. I was almost there and stopped at intersection to remove a limb from the road. Not sure WHY I shut it off (would have been easy to jump in & take off with me straining to move the branch?), but I did... and then it wouldn't start back up. Starter spun it fast, like a gasser w/ NO plugs fast, but it wouldn't hit...

I let it sit a minute, found the fuel cap lock down tight (note: still the NON-vented cap w/ huge vacuum inside the tank, so I loosened it ) tried it another time or 2 with the same results. Let it sit another minute, wiggled the wire to the fuel solenoid and it fired back up, so I went the last 1/10th mile to my buds house and shut it off again. Would NOT fire back up, even wiggling the wire (which feels pretty secure), so I don't *think* it's shutoff related.

Thoughts?

Crossy's son

GM TBI kinda guy huh? I think i found your video on youtube of your jeep if you have one

When I'm not messsing with VE pumps you'll see me under the hood of various TBI trucks, they're fun to play with