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  #1  
Old 12-12-2013, 11:14 PM
Big Dog Big Dog is offline
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Default does any one know about the cat c7?

I have a 2004 freightliner with a cat c7. Every time I start it, it idles like crap and has a dead hole, then when it hits a 125 it really goes to crap and sounds like it is back firing when accelerating and it doesn't even accelerate. If anyone on here knows about these it would be great if you could maybe help.

Last edited by stodg73; 12-13-2013 at 09:16 AM.
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  #2  
Old 12-13-2013, 09:05 AM
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stodg73 stodg73 is offline
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How many miles are on the engine?

When was the last time that you had the injectors cleaned and pop tested?

How often are you changing the fuel filter?

Have you been using a fuel additive?

You may be having injector problems and also with using the ULSD might not have enough lubrication.

Have you checked for codes, if so, what are they?
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O.O., 01.5, Dodge, 2500, High Output (H.O.) Cummins Turbo Diesel (245/505), Quad Cab Long Bed (QCLB), 4x4, Sport, Original Bosch VP 44 Injection Pump, 6 Speed/NV5600 Transmission, 3.55 Gears, 105k, currently stock engine, Fram Air Filter, 285/75R16s, Glow Shift Gauges: Fuel Pressure (FP), Boost, Exhaust Gas Temperature (EGT), Oil Temperature, SMARTY@1, Airtex lift pump 19 psi @ idle, 14 psi @ WOT, Propane Injection, 2 Stroke Oil, Intake Air Temperature (IAT) Fooler = Better MPG, Bed Lined, Chrome Nerf Bars, more to come!!

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  #3  
Old 12-13-2013, 09:18 AM
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stodg73 stodg73 is offline
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Have you checked the fuel lines to see if they are intact or plugged?

Have you tried a 5 gallon can with a fuel hose to the engine/lift pump to see if that makes it better?

Just throwing out ides here.
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O.O., 01.5, Dodge, 2500, High Output (H.O.) Cummins Turbo Diesel (245/505), Quad Cab Long Bed (QCLB), 4x4, Sport, Original Bosch VP 44 Injection Pump, 6 Speed/NV5600 Transmission, 3.55 Gears, 105k, currently stock engine, Fram Air Filter, 285/75R16s, Glow Shift Gauges: Fuel Pressure (FP), Boost, Exhaust Gas Temperature (EGT), Oil Temperature, SMARTY@1, Airtex lift pump 19 psi @ idle, 14 psi @ WOT, Propane Injection, 2 Stroke Oil, Intake Air Temperature (IAT) Fooler = Better MPG, Bed Lined, Chrome Nerf Bars, more to come!!

Toys:
'79 CJ5, 258ci, 3" lift, 33x12.50x15, Stock Engine and 3 Speed Tranny
'05 Suzuki, GSX1300R, Hayabusa, All Stock, #3('00 blown engine, '00 stolen, & '05)
The complete live & learn and pass it on by H. Jackson Brown, Jr.
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  #4  
Old 12-13-2013, 10:40 AM
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MnTom MnTom is offline
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First of all, have you pulled codes? It sounds like an injector issue, but could be the HEUI pump or both. I also located this:
Quote:
The C7 is notorious for putting metal into the heui rail due to a heui pump failure which will also cause an engine miss. A good way to check for this is to remove the fuel pressure regulator from the back of the cylinder head and inspect it for metal debris. Also remove one or both of the 5/8 allen head plugs from either the front or back of the cylinder head and run a magnet down it. The plugs are pretty tight and sometimes you have to use an air hammer with a flat bit and hammer on the top part of the head while applying pressure to the plug via a ratchet/socket combination. If you have 157-17 faults then you more than likely have a faulty heui pump and possibly a bad injector if the engine is missing as well. Another thing to check is an injector that is leaking excess oil, will be easy to tell which one is if you pull the valve cover and look at the injectors with the engine running.
Give this a try and let us know.
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1996 RAM "Custom Ground" 100 plate 3/4 forward, 300 injectors, 16.5 timing, Goerends Auto = 365HP, 833TQ Third Gen Rims, Aluminum Headache Rack
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Old 12-13-2013, 05:44 PM
Big Dog Big Dog is offline
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The trucks got a bit 145,000 on it. Additive is used every other time. Fuel filters are changed about every 12000 miles. No codes on it.
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  #6  
Old 12-13-2013, 05:45 PM
Big Dog Big Dog is offline
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If it is the heui pump how easy is it to change that?
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  #7  
Old 12-13-2013, 07:54 PM
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MnTom MnTom is offline
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From what I have read it doesn't seem to be terrible, but I have not ever pulled one and don't know what the drive system is. I was thinking, this truck has an ECM so is it possible the ECM is what your problem is? Strange though that there are no codes.
I would pull the pressure regulator and check for metal shavings. If yes, then concentrate on the HEUI pump and injectors, if not then start looking at the ECM. I don't suppose there is a Cat dealer that can do a diagnosis for you?
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1996 RAM "Custom Ground" 100 plate 3/4 forward, 300 injectors, 16.5 timing, Goerends Auto = 365HP, 833TQ Third Gen Rims, Aluminum Headache Rack
Duct Tape can't fix stupid, BUT it can muffle the sound
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  #8  
Old 12-13-2013, 08:00 PM
Big Dog Big Dog is offline
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I will look in to that. There is a cat dealer close just thought I would do some research before I go spend a bunch of money.
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  #9  
Old 12-13-2013, 08:02 PM
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MnTom MnTom is offline
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I fully understand. From what I have been reading it seems as the HEUI pump is a known problem that will take $3K+ to fix.
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1996 RAM "Custom Ground" 100 plate 3/4 forward, 300 injectors, 16.5 timing, Goerends Auto = 365HP, 833TQ Third Gen Rims, Aluminum Headache Rack
Duct Tape can't fix stupid, BUT it can muffle the sound
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  #10  
Old 12-13-2013, 08:05 PM
Big Dog Big Dog is offline
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Ya its a lot. Thanks for advice.
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