Intermittent Power Loss in Engine

[Utah Smitty]

Hi, All

I have a 1996 K2500 GMC, extended cab long bed. 184,000 miles, 4LE80 transmission, 4.10 differentials. The truck was owned by a farm in northern Idaho, and needed a lot of "corrective action" to resolve some benign neglect. The previous owner had a new injection pump installed, but not sure at what mileage.

I've done the following to it so far:
Work done late last year
- Installed air cleaner from K3500
- Installed aluminum radiator, high flow water pump for 2000 model year, Duramax Fan and new Hayden clutch, and Fluid Dampr
- Installed new engine oil cooler lines.
- Removed vacuum pump and installed manual spool stick (home made)
- Installed new timing chain and sprockets
- Replaced the "tuna can" near the turbo (forget what it's called)

Work done in the last month:
- Installed pre-pump filter and Raptor fuel pump from LeRoy diesel
- Installed Feed the Beast system from LeRoy Diesel
- Installed fuel relay bypass circuit from LeRoy Diesel
- Installed new pickup assy in fuel tank and removed strainer "sock"
- Run 1/2" hose from tank to beyond Raptor pump
- Removed soot trap and installed 4 inch exhaust
- Moved PMD heat sink from top of engine to driver's side fender and installed new Flight Systems PMD

The mechanic that did some of this work last year also tweaked the timing on the pump--he said the bolts were loose and it was out of time.

Here's my issue:

I didn't notice anything at the time, but for the last couple months I've noticed the truck will start and run fine, but then seems to go into "limp" mode and hardly accelerates, even on level ground. I don't notice any black or blue smoke, etc. although sometime the coolant temperature goes up quickly.

I had planned to put a 4 inch exhaust on it anyway, but the rest of the recent work was done to try and correct the problem... I assumed it wasn't getting enough fuel. However, the problem still persists, even on an empty truck on level ground. The EGT used to go up more before I upgraded the fuel system. Now it stays in the 700-800 degree range.

One other thing, the Antilock light came on about 3 months ago... I haven't looked into finding the cause, yet.

I've run out of ideas as to what is causing the problem.

I talked to LeRoy about it and he recommended I find someone in the local area. I'm in northern Utah, and he said there was someone on this site in the local area (Pavel?) that might be able to help me.

Can anyone give me a hand or at least let me know where to look next?

Thanks,

Smitty

 

[Will L.]

Welcome. Glad you finally found the site.
Diagnostics instead of parts cannon is the recommendation.

Any codes?
Black or grey smoke when accelerating?

Get a clear line inplace of the rubber one on the ip return side. It’s 1/4” diameter and about 5 to 6” long. Any hardware store sells some that will last a few years. Best is the clear stuff from here: https://fuel-line.com/collections/fuel-line/products/1-4-fast-flow-fuel-line-1?variant=506622081
Get new screw style clamps for it also.

Then get a permanent mounted fuel pressure gauge that is taped at the ip (injection pump) inlet with metal. Someone please post him the link to where to get it on Amazon to save a few bucks? Otherwise ModMafia sells one for $30ish.

Use an electric gauge so the sending unit screws in there and you don’t run liquid fuel into the cabin. Pressure should be 8-14 psi from idle to WOT.

Relocate your pmd out of the engine bay. Most popular spot is the backside of the front bumper by the cooling holes (those are jot for fog lights).

How EXACTLY did you retime it after the timing chain kit? Was it chain or gear drive (Leroy’s “time keeper”)?

Posting video of the issue in YouTube or similar then add a link here will help.

@Paveltolz is usually found on the salt flats of recently fishin & wrenchin in Montana! Idk his rules but I think it’s polite to show up with pizza, drinks and ammo- just be sure to use them in the right order or your truck might end up with speed holes.

 

[Utah Smitty]

Thanks, Will.

I haven't noticed any black or grey smoke when accelerating... just curious, what is the purpose of the clear return line from the IP?

I'll get a fuel pressure gauge installed.

We put in a new timing chain. We looked at the time keeper, but couldn't justify the expense. As for the timing, I don't know how it was done. I had a mechanic do it for me. He was fairly knowledgeable about 6.5s, but I seriously doubt he had any electronics to help with timing. (Leroy said it takes a computer.)

I'll also relocate the PMD-- my earlier move was just to see if the PMD was acting up, but it doesn't appear to be, as the same problem has persisted regardless of what I've done. Leroy said it might be because the vacuum pump isn't hooked up anymore and the computer is looking for input for it's sensor. He said getting a tune might help, but hopefully that won't be necessary.

Thanks again for your help.

Regards,

Smitty

 

[Will L.]

The clear tube is to watch when it is running and has the issue.
You should see just clear clean fluid flowing through. It’s ok to have one bb sized bubble traped in there ut you should not see a trail of bubbles- even a few every minute is too much. Also no discoloration or contamination in the line.

Because you have changed so many things without proper diagnosis first- there is the possibility that you have muddied the waters. So all we can do at this point is start from the beginning as if nothing has been done and test everything along the way.
We need to know results of those before proceeding

 

[jrsavoie]

Maybe this thread for the Amazon gauge T
.

Fuel pressure gauge

If you do that, just make sure no rubber hose after theT to the ip. The rubber flapper possibility inside the hose has bitten lot of people:

www.thetruckstop.us

 

[jrsavoie]

Have you ran with your fuel fill cap loose ?

Sometimes the vent in the cap plugs

Use only an AC Delco or GM fuel fill cap for a diesel.

I've never seen any of the aftermarket caps be made for a diesel, even though they claim to be.

Maybe someone else has found a brand that works

 

[Paveltolz]

Thanks for the call out @Will L. , I'm in 'reset' mode after the extended marathon engine swap at BigT's plus side trips to help Bill in WA or him and Mursik on the Flats.
Seriously though Smitty, I'm in Saratoga Springs and am willing to swing up, over or across UT to lend a hand. Just give me a couple of days to catch up on the honey do's I've avoided the last month. In all honesty, I don't know all about 6.5s but, I have a life line, who is a God Send, at my beck and call. I also have a scanner to see where the IP base timing is at and current TDCO.
Normal Pump timing should be set to 3.5 degrees prior to adjusting TDCO. TDCO is optimally -1.94. Mine's around -1.5 and nobody has complained.

To get an idea of fuel pressure, approx, you can use an inexpensive vacuum/pressure gauge attached a 4' long hose (1/4" dia) to the output side of the T-Valve and open it up. With the longer hose you can temporarily tape the gauge to the windshield to see what's going on while driving.
(Photo Credit: TurbineDoc)


If your home made manual boost controller isn't adjusted correctly, you could be pushing too much boost. Without an updated tune the computer will de-fuel at 8-10 psi so there's that to consider. There should also be a code thrown but, may not keep the Service Engine Soon (SES) light on. It may be one of those codes that just stays logged in until cleared.

Let me know what you want to do. I'm always up for a Get Together.

 

[Utah Smitty]

Have you ran with your fuel fill cap loose ?

Sometimes the vent in the cap plugs

Use only an AC Delco or GM fuel fill cap for a diesel.

I've never seen any of the aftermarket caps be made for a diesel, even though they claim to be.

Maybe someone else has found a brand that works

Good question about the fill cap. I haven't run it loose, but there is a release of pressure (vacuum?) when I open the cap... Is that normal?

 

[Utah Smitty]

Thanks for the call out @Will L. , I'm in 'reset' mode after the extended marathon engine swap at BigT's plus side trips to help Bill in WA or him and Mursik on the Flats.
Seriously though Smitty, I'm in Saratoga Springs and am willing to swing up, over or across UT to lend a hand. Just give me a couple of days to catch up on the honey do's I've avoided the last month. In all honesty, I don't know all about 6.5s but, I have a life line, who is a God Send, at my beck and call. I also have a scanner to see where the IP base timing is at and current TDCO.
Normal Pump timing should be set to 3.5 degrees prior to adjusting TDCO. TDCO is optimally -1.94. Mine's around -1.5 and nobody has complained.

To get an idea of fuel pressure, approx, you can use an inexpensive vacuum/pressure gauge attached a 4' long hose (1/4" dia) to the output side of the T-Valve and open it up. With the longer hose you can temporarily tape the gauge to the windshield to see what's going on while driving.
(Photo Credit: TurbineDoc)
View attachment 89574

If your home made manual boost controller isn't adjusted correctly, you could be pushing too much boost. Without an updated tune the computer will de-fuel at 8-10 psi so there's that to consider. There should also be a code thrown but, may not keep the Service Engine Soon (SES) light on. It may be one of those codes that just stays logged in until cleared.

Let me know what you want to do. I'm always up for a Get Together.

Thanks for the response. I'll try the fuel gauge suggestion you mentioned as I do have one as part of a tune up kit. I'll get one a permanent one installed as soon as I can. I have a boost gage, and Boost pressure maxes out about 8-9 psi right now. From what you've said, that may be causing the defueling, so I'll adjust it down a little.

I appreciate your kind offer to assist. I'm in Roy, so it's a bit of a drive. However I do have a pretty well-equipped shop including a lift, lathe, milling machine, welders, etc. plus a good selection of hand tools in metric and SAE.

It's really cluttered right now, but I can work on that to give us room to work.

I understand you enjoy powder actuated projectiles (not sure if I can use the g** or r***e term here). In addition to those items, I have some pneumatic models in various sizes from .177 to .45 you may be interested in trying out,

I'll get things ready for your visit, probably plan on sometime next week. I'm off Friday and Saturday.

I'll PM you my phone number.

I attached some pictures of the recent Raptor fuel pump and FTB filter install. I relocated the filter to make it easier to get at.

Regards,

Smitty

 

[Paveltolz]

Roy UT is easy enough. Sure a lot shorter than driving to Omak WA.
The shop sounds great. Do I guess correctly you might be a Forged in Fire kinda person? Pneumatic weaponry is great stuff. Don't need to worry so much about backstops and it really all falls down to proper hold, breathing and trigger pull. Caliber is insignificant except for that kick thing.
The relocation of the T-Valve to the FFM is an interesting concept I haven't seen before...I like it. I just got rid of it and the FFM with the AirDog.
Please don't hesitate to send your number. I'm sure between your skills, my dumb luck and the help of my life line it'll all get sorted out. I have an extra ECM that while tuned for my truck's turbo and cam etc, also has the vacuum delete and boost control limits removed so we can at least try it out and see if the defueling sorts out.

 

[Utah Smitty]

Yeah, I'm a tinkerer, and love doing things with my hands. One of my major hobbies is refurbishing old Garden tractors. I have about 12 right now... most run, but many need some work... keeps me out of the pool halls I tell my wife, whose very supportive and patient.

Some of my pneumatics have the same ballistics as a 45 ACP, and same caliber... they've been used to take deer and wild hogs, etc.

I actually studied Diesel Technology in college, along with Manufacturing Engineering Tech. Spent a few years as an Ordnance officer in the Army, where I got to play with tanks and similar items...

I'll be retiring from the Defense Contract Management Agency (DCMA) at the end of this month... Exciting, but scary...

Anyway, I'll get to work on things so we can work without having to walk around things. I've attached a few pictures from when we were first building it-- about 4 years ago.

 

[jrsavoie]

Good question about the fill cap. I haven't run it loose, but there is a release of pressure (vacuum?) when I open the cap... Is that normal?

The tank usually runs at a slight vacuum.

Seems the reason why was discussed years ago. Might have been to assist in fuel return.

The tanks still have to be vented.
There are pictures around of fuel tanks caved in by the little OEM lift pumps.

 

[Utah Smitty]

Ok, thanks.

 

[Paveltolz]

Yes, a 'slight' vacuum assists in pulling fuel back into the tank.
Utah Smitty, that's a wonderful Man Cave ya got there. Got your contact info. Next Friday or Saturday, 13-14 SEP 24, works great for me. Wife has plans for me so I can pick the day, just have to leave her one.

Retiring is a bit scary. Hardest thing for me was figuring out what to wear every day after being in a uniform for so long. My $ 0.02...give yourself a year to play around, dabble here and there, part time job or no...just chill and let what comes next find you. A couple of friends did that and I did it for about 6 months. Hang in there, trust your instincts.

 

[Utah Smitty]

Thanks, I already got the part time job. It allows me to work from home, fortunately.

 

[MrMarty51]

I soon will be ordering the Raptor LP.
Is this filter pre LP ?

 

[Utah Smitty]

I soon will be ordering the Raptor LP.
Is this filter pre LP ?
View attachment 89600

Yes, it's between the tank and the Raptor pump. I got both the Raptor pump and prefilter through Leroy diesel. You'll also get a length of 1/2" ID fuel hose and an adapter to hook it to the sending unit of the tank. I'd recommend replacing the sending unit when you do this as you'll want to remove the fuel strainer on the tank side of the pickup tube, so you'll have to remove the sending unit anway.

I also installed a Feed the Beast fuel filter which allows increased fuel flow into the final filter (located at back of engine) and into the injection pump. I choose to relocate the final filter as it's a pain to access at the back of the engine, and a major pain to reconnect the fuel fittings, etc. I used the same fuel return lines from the pump, but ran 1/2 hose from the Raptor filter to the engine bay, then necked it down to 3/8, which is what the FTB final filter uses. You can see it in some of my previous pictures.

I just used 1 1/4 x 3/16" flat bar and bent two pieces to raise the filter about 2 inches, mounting one end on the top of the air intake, and the other on the ears of the filter. I also made one brace to keep it from bounding around... I used an existing threaded hole (8mm) on the intake manifold and the other end to the front bolt on the filter. This is quite rigid and doesn't vibrate or shake. Total length of flat bar needed is about 32"--get 36" to be safe.

You'll want to get a 90 degree fitting for the injection pump vs the black135 degree fitting used if you keep the pump in the orginal location. This will make it much easier to fit the push lock fittings onto the hose.

I mounted the fuel drain on the side of the fuel filter, but routed the hose over the valve cover to the front of the engine so it's not dangling over a hot manifold. When I drain it, I'll merely pull the hose out, put a suitable container under it, and open the valve.

Hope this helps.

Regards,

Smitty

 

[MrMarty51]

Yes, it's between the tank and the Raptor pump. I got both the Raptor pump and prefilter through Leroy diesel. You'll also get a length of 1/2" ID fuel hose and an adapter to hook it to the sending unit of the tank. I'd recommend replacing the sending unit when you do this as you'll want to remove the fuel strainer on the tank side of the pickup tube, so you'll have to remove the sending unit anway.

Got that sock filther already eliminated.
QSTuning I think recommends to not install a canister filter as such. They have an inline 1/2” filter that I’ll be going to. As per their recommendations.

 

[Utah Smitty]

So I'm wanting to upgrade my turbo, probably an HX35 or HX40. I see them for sale online but don't want to buy something that isn't configured properly. What should I look for as to specs?

I've already got a used ECM to get reprogrammed, so I need to find a turbo before I program it.

Regards,

Smitty

 

[MrMarty51]

So I'm wanting to upgrade my turbo, probably an HX35 or HX40. I see them for sale online but don't want to buy something that isn't configured properly. What should I look for as to specs?

I've already got a used ECM to get reprogrammed, so I need to find a turbo before I program it.

Regards,

Smitty

I would visit with @Quadstar Tuning LLC on such matters.
They will questionnaire You with how the truck is being used, driving style and a whole boat load of questions necessary to get the right turbo and the proper tune to the way You drive Your truck and if a daily driver or a real badd @ss work horse.