Sluggish, weak, stalling

[MHalloran]

Hey all,
Truck is a 96. Temps outside in 40s...after getting my manual trans into 2nd,3rd then into 4th, engine got weak in each gear & truck bogged & got slower in speed. Tach came up normally. Getting up hills & even moderate inclines was tough. A couple times it stalled when coming to a stop sign. Fuel solenoid still pulls up when ignition is on. (I replaced it once some years back) Relays are original. Could it be one of those? Fuel filter needs changing? (There’s no white smoking going on) A hole in a vacuum line/hose? Any ideas/suggestions would be so appreciated. Thanks!

 

[Bill Lins]

When mine got weak, it turned out to be the lift pump (check valves, according to the mechanic). Replaced the pump & power was back. But check for a clogged fuel filter first.

 

[MHalloran]

When mine got weak, it turned out to be the lift pump (check valves, according to the mechanic). Replaced the pump & power was back. But check for a clogged fuel filter first.

Thank you Bill. I’m hoping it’s not the lift pump. I know it’s not a hard to do swap but I’d rather not get into that. Toughest thing is getting your hands near it. This pump is a mechanical item so I’m wondering what might go wrong with it? I’d like the fuel filter option to try first so I’ll try the swap since I have one in garage. Thanks for your reply Bill.

 

[GAmes]

Insure the FSS is fully moving and the FSS bracket is firmly attached to the top of the IP. If it is only partially up the engine will start and run great, but will bog down when the power is needed.

 

[MHalloran]

Insure the FSS is fully moving and the FSS bracket is firmly attached to the top of the IP. If it is only partially up the engine will start and run great, but will bog down when the power is needed.

GAmes, I’ll look at it again tomorrow. When I turn ignition to on position it never did slide up all the way (in the past.) I figured the vibration of engine cranking would cause it to slide up all the way then it would start & run & solenoid would stay up. When you turn key on & not crank is it supposed to go to full on ( up) position on it’s own? You think relay is weak? Solenoid is going bad? I’m curious about this. I know you’ve been on this sight for a long time & I know you’ll have a good idea brother...what’s your take? I’m hoping it’s not a lift pump issue. I’m hoping not to be messing with that. My bed is full of yard brush I need to get rid of. That’s where I was going today but I aborted the trip to get truck home. Glad I made it after a couple of engine stalls & the way it was running. Thanks man

 

[GAmes]

To pull the piston up requires turning the key to start. Once it is running a different circuit holds it up. The most common cause of no full travel is a deteriorated boot binding everything up. In addition I have had the rod break free from the piston and also the bracket bolts vibrate out and the bracket fall away. Lift pumps normally last about 300k miles, but have been know to fail sooner. A fuel pressure gauge is the best way to diagnose that issue.

 

[MHalloran]

To pull the piston up requires turning the key to start. Once it is running a different circuit holds it up. The most common cause of no full travel is a deteriorated boot binding everything up. In addition I have had the rod break free from the piston and also the bracket bolts vibrate out and the bracket fall away. Lift pumps normally last about 300k miles, but have been know to fail sooner. A fuel pressure gauge is the best way to diagnose that issue.

Ok thanks , I’ll have a closer look at it tomorrow. While I’m at it maybe I’ll throw in a fresh fuel filter too. Hey while I have you, what are your thoughts on lift pump? Is there a weep hole that shows fuel leak should the internals fail inside? What would actually cause this part to go bad? Other signs as in like, my symptoms? Thanks again...

 

[GAmes]

They wear out. The pump has two independent pistons, one for the hand primer that only gets used when you prime the system and the engine driven one. As often as not the return spring for the push rod gets weak and the rod starts tapping on the cam lobe. Other times they just quit. There isn't a weep hole. If an internal seal fails you'll get a crankcase full of fuel. That happens very seldom. Once again, a fuel pressure gauge is a plus. It will tell you if you need a filter. A lot of people don't change their filters until the pressure starts dropping off.

 

[MHalloran]

They wear out. The pump has two independent pistons, one for the hand primer that only gets used when you prime the system and the engine driven one. As often as not the return spring for the push rod gets weak and the rod starts tapping on the cam lobe. Other times they just quit. There isn't a weep hole. If an internal seal fails you'll get a crankcase full of fuel. That happens very seldom. Once again, a fuel pressure gauge is a plus. It will tell you if you need a filter. A lot of people don't change their filters until the pressure starts dropping off.

Ok so where is best place to get a gauge/fittings setup, Geno’s? & where is best place on engine to install it? Should I need a new lift pump, there’s a rod that rides on cam lobe correct? A separate piece that slides right out (usually, hopefully?)

 

[GAmes]

The best place for me was Genos, but my installation isn't for everybody. I chose an EV2 gauge that fits in my gauge pod with boost and EGT. Some people like the less expensive manual gauge, but I don't want a fuel line coming into the cab. Larry B sells one that fits under the hood. http://www.fostertruck.com/dodge/fu...ressure-gauge-for-dodge-12-valve-94-98-5.html My installation involved tapping the banjo fitting into the pump (drill it from the backside to keep the drill bit centered) to 1/8 npt and installing an 18 inch flex grease gun hose. To that I attached a needle valve with 1/8 npt female fittings on both ends. The sender to the gauge attaches to it. The needle valve is just barely cracked open. The needle valve is needed because the manual lift pump pulses so hard it will ruin a gauge in short order. Some people use a snubber, but I have read many reports of snubbers causing poor gauge readings.

The push rod for the lift pump will slide out while removing the pump if you're not careful. As far as I know it won't cause any damage in the bottom of the oil pan. It is held into the pump by friction alone.

These are both ends of the grease gun hose.

 

[MHalloran]

The best place for me was Genos, but my installation isn't for everybody. I chose an EV2 gauge that fits in my gauge pod with boost and EGT. Some people like the less expensive manual gauge, but I don't want a fuel line coming into the cab. Larry B sells one that fits under the hood. http://www.fostertruck.com/dodge/fu...ressure-gauge-for-dodge-12-valve-94-98-5.html My installation involved tapping the banjo fitting into the pump (drill it from the backside to keep the drill bit centered) to 1/8 npt and installing an 18 inch flex grease gun hose. To that I attached a needle valve with 1/8 npt female fittings on both ends. The sender to the gauge attaches to it. The needle valve is just barely cracked open. The needle valve is needed because the manual lift pump pulses so hard it will ruin a gauge in short order. Some people use a snubber, but I have read many reports of snubbers causing poor gauge readings.

The push rod for the lift pump will slide out while removing the pump if you're not careful. As far as I know it won't cause any damage in the bottom of the oil pan. It is held into the pump by friction alone.

These are both ends of the grease gun hose.

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Hey I really do appreciate the time you’re taking to assist in my issue here. What year is your truck? Old like mine? My truck is luckily not my daily driver. I’ve kept it for when I need a truck like we all do at times. It’s always been dependable. So this LarryB gauge installs in same spot you hooked your grease gun hose to? ( I like your install. Appreciate the pics) A gauge is important to me now at this point because I really DO NOT want to buy & mess with installing a lift pump if I don’t need one. I have 236k miles on truck. I spent a hour pulling out the old solenoid before. It was time & it made me sad seeing what father time does to our trucks. Corrosion. One of the 3 bolts holding the bracket on sheared when loosening. (I hate that feeling ) Luckily it was the center one. Both ends should be enough to secure the new one when I get it, I’d say. (There’s no way I can easily drill out that sheared piece) Boot had a tear in it also. So I’ll get a gauge setup ordered & get it in. So once done I’ll be looking for about 18-24 psi at idle & 26-35 psi at 2k rpm... this sound about right? How about your feeling on LarryB solenoids vs. ones on Amazon? Prices vary...
Oh & this gauge setup I’m gonna leave under the hood or remove when done. Like I said, it’s not my daily driver & needing to see fuel pressure is primarily at this point to check for faulty lift pump. I may doctor it up better & leave in. I’ll see what happens...thanks man I’ll keep you posted.

 

[GAmes]

I guess you are on a phone and can't see signatures? Mine is a '97 with close to 1.4 million miles on it. If the boot on yours is deteriorated just pull it off, clean the plunger and reinstall. I ran without a boot for years and Big Papa doesn't have one now IIRC. Larry B also sells just the boot if you feel you need one. Larry B's gauge mounts on top of the fuel filter housing. Do not even think about drilling the broken bolt. It goes into a blind hole and trying to drill it only will send metal particles into the AFC. As often as not with the bracket removed you can screw the broken shank out with your fingers. Solenoids rarely fail so I recommend you remove yours, clean it up and try it. Adjusting the linkage is covered in the factory service manual. If you do need to replace the solenoid Larry B and Genos would be the places I recommend.

 

[MHalloran]

I guess you are on a phone and can't see signatures? Mine is a '97 with close to 1.4 million miles on it. If the boot on yours is deteriorated just pull it off, clean the plunger and reinstall. I ran without a boot for years and Big Papa doesn't have one now IIRC. Larry B also sells just the boot if you feel you need one. Larry B's gauge mounts on top of the fuel filter housing. Do not even think about drilling the broken bolt. It goes into a blind hole and trying to drill it only will send metal particles into the AFC. As often as not with the bracket removed you can screw the broken shank out with your fingers. Solenoids rarely fail so I recommend you remove yours, clean it up and try it. Adjusting the linkage is covered in the factory service manual. If you do need to replace the solenoid Larry B and Genos would be the places I recommend.

I am on a phone yes. 1.4 million miles?? You must live in a state where there’s not much moisture & NO winters with 3-4 months of cold weather with road salt & liquid brine solution painted on roads. ( like in Jersey here ) That truly did mine in when it was my daily driver for the first 10 years I had it. If you could see my poor undercarriage (& more, along with the body) you would cringe like I do every time I’m underneath it. I can’t say what’s holding the truck together anymore & I just refuse to part with it. I’ve owned it since it’s birth & I still love it. I still try to do what I can to keep it going. It was a struggle to get the solenoid plunger arm off the linkage. The whole thing is not in good shape so instead of trying to dress it up I’ll just buy new.
Yea there’s no way I’m gonna attempt drilling any broken bolts out. Too risky I know. One on each end of bracket will work for me. New ones come with boots too. If lift pump proves good then I need to find a new rubber plunger cover too. That is also falling apart. ...Ok so I need to order a fuel pressure gauge like you mentioned & a new fuel solenoid setup. Put these in with a fresh fuel filter & then keep my fingers crossed in my first drive. I’ll be in touch & keep you posted brother. Thanks so much once again.

 

[DavidC]

There use to be a guy on here in Vermont that had a green 99. He drove that thing until it totally desintegrated from the road chemicals. A real shame to watch the then $35k truck fall apart under you.

 

[GAmes]

I'm in TX but a lot of those miles were accrued while winter driving in the north. I guess the difference being that I could pressure wash the under carriage when I got home and always with just plain water. I never attempt to remove the layer of oil that protects the metal.

 

[MHalloran]

There use to be a guy on here in Vermont that had a green 99. He drove that thing until it totally desintegrated from the road chemicals. A real shame to watch the then $35k truck fall apart under you.

I know the feeling. Such a strong reliable engine with a wrapping that won’t (hasn’t) matched its’ longevity

 

[MHalloran]

I'm in TX but a lot of those miles were accrued while winter driving in the north. I guess the difference being that I could pressure wash the under carriage when I got home and always with just plain water. I never attempt to remove the layer of oil that protects the metal.

How are you today? I haven’t gotten back out to driveway to work more on truck. The temps outside are too damn cold. Needs to get a little warmer. I thought more about getting a new solenoid. What I did was take my old one apart to clean it up. Boot is ok so I’ll reuse also. I saw another article on line concerning my issue with all this. A possible fusible link issue? When I turn key on my relay doesn’t pull plunger up all the way but when I pull up on it it stays where it needs to. Could be weak link? I’ll pick up a new one & swap it out just go see. I think NAPA sells them for $4. It’s only in the 20’s outside today so I’m not working on it today.
Hey that was a smart idea you had about coating your undercarriage with a layer of thin oil. It has saved yours from Mother Nature. I’ll be in touch with my progress as it goes brother. ......Mike

 

[GAmes]

Just to be clear, the solenoid isn't supposed to pull up with just turning the key on. The start position sends a signal to the relay that pulls the solenoid up. If the starter cranks but the solenoid doesn't go up it could be the fusible link. I'll be in western TN on Tuesday. Temps are forecast to be in the teens.

 

[MHalloran]

Just to be clear, the solenoid isn't supposed to pull up with just turning the key on. The start position sends a signal to the relay that pulls the solenoid up. If the starter cranks but the solenoid doesn't go up it could be the fusible link. I'll be in western TN on Tuesday. Temps are forecast to be in the teens.[/QUOTE
Ok. So then if I go “key on” then crank it a few seconds & release key then check solenoid, should the plunger remain full up position or would it drop back down some? What might you think? Hey enjoy the TN temps when you’re there. The cold sucks. I hate it.

 

[GAmes]

If you don't turn the key off the solenoid should be up.