Surging, Stalling and engine miss

[Turboman]

Below is the diagnostic sheet. In need help resolving issues as described in the header. After installing a new PMD from PMD cable with no improvement I am inclined to believe it is a fuel problem, especially since the fuel reading is so high. The pressure reading is always between 5 and 7 lbs. 7lbs. seems good, but I don't know why it never falls below 5 lbs. unless I have a blockage somewhere after the FFM. Any Ideas????

Demographics: tell us about your truck and your ambient conditions:

- Year: _1998_____
- Truck model and class (ie: c2500) _3500 4X4________
- Automatic or Standard _Auto_________
- Mileage: (indicate miles or km) __131890_______
- Replaced parts and mods (IP, PMD, chip/PCM, TM, injectors etc) _Fuel filter, PMD__________
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR? _F_____________
- Ambient outside temp: (indicate *C or *F) __89*F________
- What fuel are you using? (#1 Diesel, #2 Diesel, Bio, VO, WVO, etc) _#2________
- What fuel additives are you using? _30WND__________
- Where are you located? _Spfld., Ohio____________

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter _Don't know________
- Fuel filter _New________
- CDR Valve? _Don't Know________
- Coolant – last flushed/replaced at _Don't know____________
- Oil – synthetic/regular, changed at _15W40 128850__________
- Batteries – state of charge, (matched set) replaced at _125000 fully_ charged___________
- Battery cables and grounds (removed, cleaned and tightened): __Removed, cleaned tightened, 3/8” bolt modification____________
- Glow Plugs - how many miles on them? 131000_________ What type? _60____________
- Injectors - last changed at _Original______________


History: (Describe how the problem first appeared.)
- What were you doing when it happened? _Driving down road, coming to a stop sign behind car stopped at stop sign_____________
- How was the truck running fine before this problem appeared? __No problem___________
- Has this problem ever happened before? _Surging several times in reverse prior to this instance______________________
- Describe any related factors that might be part of the problem. ______________
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) _Y___ And? __No codes and ne SES______


Diagnostics:

1] Starting:
1a] Does the engine start? _Yes________
1b] Does the engine crank over? __Yes______
1c] Are your batteries fully charged? _Yes________
1d] Have you removed, cleaned, and tightened all battery connections? _Yes_______
1e] Does your Wait to Start light come on for a time? How long? _Yes________
1f] Does your glow plug light come on? _Yes________ For how long? _________
1g] Do you see smoke from the exhaust while cranking? What color? _No smoke during cranking_______
1h] Does the Service Engine Light Glow during Start/bulb check? ___Yes_____

2] Fuel Issues (if not running):
2a] Can you hear your lift pump working? _Cannot hear working, but can feel it “clicking”___________
2b] Do you get a steady flow of fuel from the water drain (T-handle) ? _Yes________
2c] Loosen the inlet line from the IP – is fuel coming out (Lift Pump on)? _Haven't tried__________
2d] Loosen an injector line and crank the engine - does fuel come out? _Assuming yes since it runs________
2e] Do you hear a vacuum (hiss) when you remove the fuel cap? _No__________

3] PMD / IP Issues
3a] Location of PMD (on pump, on intake, remote mounted) __Behind bumper_________
3b] Condition of Extension harness (if used) Vendor or Homemade? _PMD Cable 2 months old________
3c] Condition of grounds / ground wires to IP / PMD. Check Harness. _All are OK________
3d] PMD Make: _PMD Cable (Flight Systems)__________
3e] PMD Age: _Brand new____________

4] Stalling Issues
4a] Do you experience stalling only when hot? __So far yes__________
4b] Does it stall under particular circumstances? (ie hit bump, or on accel) Stalls at idle only______
4c] Does pouring cool water over the IP seem to help with restarting? _Starts immediately with out doing anythinh else_ _______
4d] Is stalling momentary (engine recovers)? _Yes, sometimes________
4e] Does SES light come on when engine hiccups? _No________
4f] Does cruise control quit working when engine hiccups? _No__________
4g] Does re-starting seem to reset engine, restoring cruise and power? _________
4h] Changes to dash lights or instruments during stalling events? ___________

5] Running Issues
5a] On cold start, does upper rad hose get hard before engine warms up? _No______
5b] Any bubbles or oil film in coolant overflow tank? _No______
5c] Any white slime on oil surfaces (dipstick, CDR, oil Fill cap)? __No________
5d] Excessive white smoke from exhaust on cold start? _No________
5e] Excessive black smoke from exhaust under hard acceleration? __No, only see black smoke during surging/ stalling when engine recovers by itself________

6] Performance Issues
6a] Do you have gauges (boost, EGT) ? _Yes__________
6b] Maximum boost under load? _12___________
6c] Have you added a performance PCM (reflash) or Chip? _No_____________
6d] Have you changed exhaust / downpipe / crossover? _New crossover_______________
6e] Wastegate – mechanical or vacuum (OEM)? __Vacuum OEM____________

7] Temperature-related Issues:
7a] Single or dual thermostats? _Dual___________
7b] Have you replaced them lately? Manufacturer of replacements? __NA_______
7c] Have you pulled and cleaned Radiator and coolers lately? __No__________
7d] Have you replaced the fan clutch? Manufacturer of replacement? _No_______
7e] (winter) Have you tested your antifreeze? Good to what temp? __-35________
7f] (winter) Are you using a winter grille cover? __No_________

List and describe any other factors which are not addressed in this checklist. The truck feels like a miss or FB during heavy acceleration. After a easy run it misses and stalls at idle. It does and has started to surge at stop lights and other low RPM conditions. Fuel pressure was checked at the fuel drain and the readings don't make sense. During idle it holds a steady 7 lbs. During acceleration and running at 2000 RPM unloaded it maintains a steady 5 lbs. . This seems high as I think it should drop to 2-3 lbs for a good pump. The pump looks original and is a Airtex pump. It seems like I have a fuel problem but I am confused and am not sure where to go from here.

 

[ak diesel driver]

could be as simple as a dirty filter. If your putting the guage on the water drain t it's reading pressure pre filter. Also check it out for air in the fuel. Put a piece of clear tubing on the return coming out of the IP and watch it for bubbles.

 

[buddy]

What is your mileage like, any recent difference? And what is your idle rpms? Do you know what the TDCO value is set to, or if IP, CPS, or PCM had ever been replaced?

Your return line may be restricted. You can try blowing it out. Or perhaps you have some fouled injectors. Or a stuggling IP. If you had access to a scanner would provide a little more insight. How long have you been using ND SAE30?

 

[Turboman]

Air filter gage indicates 50% restriction and is still in the green.
Will try the clear tubing on the return line.

As far as I can tell, there has been no change in mileage. Mileage has always been low around 12 MPG.
Idle RPMs per dash gage indicate around 500-550 and jump up to 700-800 when it surges.
I have a scan tool so I need to take a look at the idle RPMS and get more detail.
using ND SAE30 for 6 months
I know the IP was replaced once by PO, but a struggling IP was on my list of concerns.

 

[bison]

could be a dirty mess screen in the IP inlet or collapsed hose post filter if what AK suggested dont pan out.
The constant high presure indicates the fuel is not getting where it is supposed too.
Could be a weak IP tranferpump too

 

[buddy]

Something isnt right if you only get 12mpg. and for a 98 I would expect idle to be closer to 700. So it could be its starved and the surging is it trying to get to normal. You can T the input to the IP and watch your pressure there. Does the engine bay smell like diesel fuel?

If you have a scanner that can show engine parameters you need to look for desired idle value, vs actual, then what is TDCO, what is desired injection timing vs measured, and what is the reported pulse width.

 

[Badaxe]

A little bump. My 94 has almost identical symtoms so I'm interested in what you find.

 

[Turboman]

Badaxe;
I'm still working thru this, so I'll let you know when I find out. I'm taking it to Northwest Injector Service tomorrow to get their help.

 

[buddy]

If going somewhere to diagnose it, best you go armed with ideas to tell them what to look at and get values or printouts of screens for you. To both prove they did due diligence and to help you diagnose if they recommend part swapping.

 

[Turbine Doc]

Do not buy an IP at this point, you have more diagnostics to do 1st

 

[Turboman]

I got my truck back from Northwest Fuel Injection Service on Monday. It runs very smooth and starts instantly. The following work was accomplished:
New Duratherm glows installed. Old plugs were severely swelled and I was unable to get them removed.
New injectors were installed. Old injectors had 131000 miles on them. You can really tell a difference in the trucks performance , very smooth running.
A new IP was installed. This corrected my surging, stalling, and missing issues.
Northwest checked fuel pressure and fuel system during troubleshooting . They found same readings that I previously found:
No SEL and no codes. 7psi on FFM inlet, 5-6 psi on IP inlet, no air in system and return line open. Guess I am just blessed with a good Airtex LP with good pressures.
Like I just said, truck starts and runs very well!

 

[buddy]

Glad its back up and running so well. This is the typical result of bringing it to a shop, and at least you absolutely know it wasnt just a PMD that they stick other people with.

Let us know if fuel mileage improves, and what is the idle RPM now that its working correctly?

One thing I would recommend for anyone before bringing it to a shop expecting to have an IP replaced is taking the air intake off and inspecting fuel lines before disturbing them. A line pinched or eroded could cause issues. And take IP inlet fitting out to inspect the filter screens on it.

Your lift pressure actually seemed alright, pressure typically recovers when cruising, and mainly dips on acceleration. Although I guess you could see if it is still the same. Getting some scanner readings could have provided additional insight, or aided in the diagnosis of a misbehaving IP. If so many people havent been screwed before and we havent witnessed first hand the typical technicians "troubleshooting" process then we probably wouldnt be so skeptical of them. There is no doubting that IPs commonly crap out though.

 

[JiFaire]

This is the typical result of bringing it to a shop,

Yep - they changed pretty much all the moving parts except the wipers...

Glad it's running well. Boy, it would be disheartening if it wasn't, after all that!

 

[Turboman]

Well, I guess I should have done the wipers too! HaHa

Engine RPM is 600 RPM +- 4 RPM

I'll need to check fuel mileage over the next several weeks. I'm hoping for some improvement over what I was previously getting. 14 to 16 MPG would be great in my book.