• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Possible vacuum pump problem

temhow

New Member
Messages
4
Reaction score
0
Location
Walstonburg, NC
Problem: Explain your problem in concise language (ie: Cranks but won’t fire). __Codes 31,32,33,78. Turbo not running right __________________________

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

- Year: _1995_____
- Truck model and class (ie: c2500) _C1500________
- Automatic or Standard ___Auto_______
- Mileage: (indicate miles or km) __126600_______
- Replaced parts and mods (IP, PMD, chip/PCM, TM, injectors etc) __Heath PMD relocater, new alternator, turbo solinoid and vacuum pump_________
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR? ___S Turbo___________
- Ambient outside temp: (indicate *C or *F) __75 F________
- What fuel are you using? (#1 Diesel, #2 Diesel, Bio, VO, WVO, etc) _#2 Diesel________
- What fuel additives are you using? _____None at present time_____
- Where are you located? __Eastern NC__________

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter _7000 Miles________
- Fuel filter __3000 Miles_______
- CDR Valve? _1000 Miles______
- Coolant – last flushed/replaced at ___10/2008__________
- Oil – synthetic/regular, changed at ___Rotella 15W-40________
- Batteries – state of charge, (matched set) replaced at ___Matched 09/2007__________
- Battery cables and grounds (removed, cleaned and tightened): ______07/2009_______
- Glow Plugs - how many miles on them? _Possibly original________ What type? ___unknown__________
- Injectors - last changed at __Possibly original___________


History: (Describe how the problem first appeared.)
- What were you doing when it happened? _Driving at 60MPH_____________
- How was the truck running fine before this problem appeared? _____Yes________
- Has this problem ever happened before? ______last 2 months about every 2 days________________
- Describe any related factors that might be part of the problem. _______turbo seems to spool up one time and then it doesn't seem to work until engine is recranked_______
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) _Y___ And? __31,32,33,78______


Diagnostics:

1] Starting:
1a] Does the engine start? ___Y______
1b] Does the engine crank over? ___Y_____
1c] Are your batteries fully charged? ___Y______
1d] Have you removed, cleaned, and tightened all battery connections? ____Y____
1e] Does your Wait to Start light come on for a time? How long? _________
1f] Does your glow plug light come on? __Y_______ For how long? __5-6 seconds______
1g] Do you see smoke from the exhaust while cranking? What color? ___N_____
1h] Does the Service Engine Light Glow during Start/bulb check? __Y______

2] Fuel Issues (if not running):
2a] Can you hear your lift pump working? ____________
2b] Do you get a steady flow of fuel from the water drain (T-handle) ? _________
2c] Loosen the inlet line from the IP – is fuel coming out (Lift Pump on)? ___________
2d] Loosen an injector line and crank the engine - does fuel come out? _________
2e] Do you hear a vacuum (hiss) when you remove the fuel cap? ___________

3] PMD / IP Issues
3a] Location of PMD (on pump, on intake, remote mounted) _____Remote ______
3b] Condition of Extension harness (if used) Vendor or Homemade? __Good Vender_______
3c] Condition of grounds / ground wires to IP / PMD. Check Harness. __Good_______
3d] PMD Make: __Stynadine________
3e] PMD Age: ___3 years________

4] Stalling Issues
4a] Do you experience stalling only when hot? ____________
4b] Does it stall under particular circumstances? (ie hit bump, or on accel) ______
4c] Does pouring cool water over the IP seem to help with restarting? _________
4d] Is stalling momentary (engine recovers)? _________
4e] Does SES light come on when engine hiccups? _________
4f] Does cruise control quit working when engine hiccups? ___________
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? _______
5b] Any bubbles or oil film in coolant overflow tank? ___N____
5c] Any white slime on oil surfaces (dipstick, CDR, oil Fill cap)? ___N_______
5d] Excessive white smoke from exhaust on cold start? __N_______
5e] Excessive black smoke from exhaust under hard acceleration? ____Y______

6] Performance Issues
6a] Do you have gauges (boost, EGT) ? ___N________
6b] Maximum boost under load? ____________
6c] Have you added a performance PCM (reflash) or Chip? ___N___________
6d] Have you changed exhaust / downpipe / crossover? _____N___________
6e] Wastegate – mechanical or vacuum (OEM)? ___Vacuum OEM___________

7] Temperature-related Issues:
7a] Single or dual thermostats? ___Single_________
7b] Have you replaced them lately? Manufacturer of replacements? __10/2008 from GM_______
7c] Have you pulled and cleaned Radiator and coolers lately? ______N______
7d] Have you replaced the fan clutch? Manufacturer of replacement? _____N__
7e] (winter) Have you tested your antifreeze? Good to what temp? __________
7f] (winter) Are you using a winter grille cover? ___________

List and describe any other factors which are not addressed in this checklist. We can’t see, hear, smell, or touch your truck, so the more descriptive information you can give, the more likely it is that somebody can assist you.

__Engine loses RPM for a couple of seconds and sets codes. Cruise continues to work. Will run alright afterwards, but turbo doesn't seem to be working after first time truck is driven down the road._______________________________
 
Welcome Temhow, codes 31, 32, and 33 are EGR codes and 78 is not on my list.

This would all indicate vacuum issues, I would start with putting a vacuum gauge coming off the pump and trace all the way to the solenoids. There are alot of plastic fittings that get brittle and break. There maybe be a vacuum diagram on your fan shroud. If not let me know and I can get a picture and post it.
 
I've had a vacuum gage on truck. I'm getting 26" at pump and at turbo solinoid. I get 14" at wastegate can. I put gage on and have rode down the road and vacuum stays good but it hasn't stuttered while I had gage on it.
 
While you have the vacuum gauge on, get under the hood and start flexing all the vacuum lines, there maybe a cracked one and it is sitting in a good position at the moment. To affect both the EGR and waste gate, I would think the line from the pump up to the solenoids.
 
I hooked vacuum gage up again when I got home from work. The vacuum now was 15" at wastegate solenoid and 11" at wastegate. Moved lines around and vacuum gage reading was very erratic. I'll check vacuum at vacuum pump tomorrow. Then I will look at lines better and see what needs to be replaced. I'll let you know what I find. Thanks
 
78 is in many cases the waste gate solenoid gone south.

If you are having intermitent issues, check the grounds at the rear of the intake on the RH side of the engine.
Battery grounds and be sure you haved 14V to the power feed lug.

Voltage and grounds will drive this stuff nuts

Missy
 
Back
Top