95 2500 Cummins auto - seems luggish and low on power

[Rogan]

Hi, first real post here; please forgive me if this has been asked before (I briefly searched with no real answers.)
I've very new to the POV diesels (this is the first one) and rusty with commercial ones (we owned a few Freightliners and Petes, when we had our hay farm, hauling hay from Hagerman, NM to Lamar, CO.)
I've got a '96 2500 Ram Cummins, automatic. Mods are only in the exhaust, being that it's turned down/open right after the cat. Everything else is stock/OE.
Here are my current issues:

1. Hard Starting when it's been sitting a few hours, especially if it's cold
2. Seems low on power; doesn't pull very strong at all, taking a good 10-15 seconds to get to 50mph from a stop
3. Block heater seems to do nothing for aiding starts on cold mornings

- #1: I haven't tested the grid heater, but it appears to be cycling, because once it's started, the battery gauge will cycle between 14 and 12vdc in roughly 5 second intervals, for about 2-3 minutes after I finally get it to start (which requires depressing the throttle pedal 1/2-3/4 way down.)
- #2: from about 40mph, you can floor it, and it barely increases speed. maintaining 70mph is a little bit of a chore, as well (~18-1900rpm cruise) 65 is more comfortable for it. 70, IMO takes way more pedal pressure/travel than it should. From a stoplight, it's 0-20 is ok, 20-50/60 is weak, at best. Around town, it feels fine, for the most part.
- #3: given the issue with it being a total bear to start in 40*F, I can only imagine what this winter will bring to it.. I plugged the block heater in, and within a minute or so, I could 'hear' the block heater getting warm, sounding as though the coolant is warming up around the element. I left it plugged in all day sunday evening, and through the night. Monday morning, 38*F, it took me 5 minutes to get it started..


Any assistance is greatly appreciated.



Cliff Notes:

Before any changes, it would barely get out of it's own way, let alone someone else's way.

To date (5-NOV-09), I've installed:
KDP fix - $20
3K GSK - $120 shipped
Fuel Filter - $26
Pre-Filter cleaning - Free
AFC full-forward - Free
Starwheel full-forward - Free
#10 fuel plate - $35 shipped
BHAF - $60
Cat/Muffler removal, replaced with 4' of 4" straight + 3"to4" adapter + 4" turn-down - $75
Transmission TV cable adjustment (longer by 1/4") - Free
After above mods/changes/maintenance, it's a completely different animal that is hard to keep under 70mph on the highway.

__________________
'96 RAM2500 CTD SCLB 4x4 Auto, 3.5:1 D70 LSD - BHAF, KDP fix, catless 4" with turn-down after the cab, 3K GSK, #10 torque plate, boost/pyro gauges, 5th wheel setup, Pioneer cd player, crank-em-up windows - otherwise, it's a boner-stocker

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Last edited by Rogan : 11-05-2009 at 03:41 PM.

[rallye12ctd]

Welcome to the site! The first two thoughts of mine are an air leak, or the overflow valve.

Joe G's fuel system writeup

I noticed a little more pep from my engine once I had my fuel/air leaks fixed. When you try to start it, are you getting fuel as far as the injectors?

ALSO- When is the last time you changed your fuel filter?

__________________
98 12 valve 5 speed. Longbox. BHAF. Silencer ring gone. Stock otherwise.

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Last edited by rallye12ctd : 10-20-2009 at 12:42 PM.

[illflem]

As said you more than likely have an air leak.
'95s are complete dogs when stock.
After you get your leak fixed read this Diesel Database :: Turning Up A P7100 Pump

__________________
Bill
'95 2500 4wd auto
'95 3500 5 speed heavy hauler
Not stock

[Rogan]

Thanks for the quick response. I'll check that thread out.. Honestly, I've done no testing whatsoever on it, as I don't even know where to begin, let alone any 'special' tools, other than my gas-turbo car tools
So as for fuel at the injectors, I've got no idea, nor how to best test that (yet).

__________________
'96 RAM2500 CTD SCLB 4x4 Auto, 3.5:1 D70 LSD - BHAF, KDP fix, catless 4" with turn-down after the cab, 3K GSK, #10 torque plate, boost/pyro gauges, 5th wheel setup, Pioneer cd player, crank-em-up windows - otherwise, it's a boner-stocker

[Rogan]

I was reading this, on your link, ill:

Star Wheel Adjustment


To adjust, remove the large plug on top of the AFC housing using an 8 mm allen wrench. Take care not to loose the sealing washer under the plug. Removing the plug exposes a star wheel which changes the quickness of fueling response to boost. If acceleration is weak with minimal smoke, rotate top of the star wheel toward the engine a few revolutions. If vehicle has heavy black smoke on initial acceleration, rotate top of star wheel away from engine a few revolutions. Reinstall large plug with sealing washer and test drive vehicle again. It may take repeated attempts to get this adjustment set. If heavy smoke is still encountered with star wheel moved completely to rear position, loosen AFC housing and slide it rearward a 1/16 inch, retighten and test again. Repeat unit desired results occur.

mine makes almost no smoke at all, and is very weak. Heck, even on cold startup, there's almost no smoke visible.. ??

I'll also check the solenoid action to see if it's pulling the arm up fully, for my hard-start problems, as well..

__________________
'96 RAM2500 CTD SCLB 4x4 Auto, 3.5:1 D70 LSD - BHAF, KDP fix, catless 4" with turn-down after the cab, 3K GSK, #10 torque plate, boost/pyro gauges, 5th wheel setup, Pioneer cd player, crank-em-up windows - otherwise, it's a boner-stocker

[rallye12ctd]

You shouldn't really need any specialty tools to diagnose and repair an air leak. There is a manual primer button on the side of your lift pump. (Above your starter on the drivers side) Try priming the truck before you start it next time, press the button 30 or 40 times. I reccomend a wooden dowel, is it is in a difficult position to reach. Let us know if it starts better.

Here is a picture
12 V Cummins informative picture

__________________
98 12 valve 5 speed. Longbox. BHAF. Silencer ring gone. Stock otherwise.

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Last edited by rallye12ctd : 10-20-2009 at 01:23 PM.

[Rogan]

I went home at lunch, dropped off the Talon TSi, and brought the truck back to work.. When I turned the key to RUN, I checked the solenoid/arm position (the solenoid is about 1/75-2" diameter, just in front of the brake master cylinder, mounted off the intake area?). I moved the arm upward to a full-up position with my finger. it moved about 1"... Truck started right up. Watched the voltage gauge cycle 12-14v as the grid heater was 'warming'.. I let it run about 30 seconds, and shut it off, rechecked the sol. arm. It was all the way down. Turned the key back to RUN, rechecked the arm, it was still down. raised it with my finger, and it started right up.

I did not see the 70A relay, nor a blue wire at the battery. Truck is 8/95, and is titled a 95 (driver's side airbag only)..

Thanks for the link, rallye12

__________________
'96 RAM2500 CTD SCLB 4x4 Auto, 3.5:1 D70 LSD - BHAF, KDP fix, catless 4" with turn-down after the cab, 3K GSK, #10 torque plate, boost/pyro gauges, 5th wheel setup, Pioneer cd player, crank-em-up windows - otherwise, it's a boner-stocker

[rallye12ctd]

Good work!

Unfortunately they are a common problem. Hopefully this was the only issue.

__________________
98 12 valve 5 speed. Longbox. BHAF. Silencer ring gone. Stock otherwise.

[Rogan]

this evening, after work, I checked on a couple things..

the 'blue' wire is clean and tight at the battery. When engine is warm, the fuel shutoff solenoid operated normally (opens/closes fully.) apparently, only when it's cold, does it not operate full range.

the AFC has one flat-tip screw, two 8mm bolt heads, and a shear-head bolt in it, so apparently, it hasn't been touched since factory?

The KDP mod is completed, as well as the front seal, now, too..

I took the liberty to install a BHAF, and the silencer ring is not in place. either it never had one, or it's already been removed.
Visual inspection resulted in no obvious cuts/abrasions in the FMIC couplers, but I don't have enough daylight left today to do the pressure test, unfortunately..

I took it a test drive around the block, and the turbo whine is... well, LOUD.. 2nd gear roll, about 20mph, a full-throttle punch resulted in a somewhat slow acceleration, and ZERO noticable exhaust smoke.. is it running THAT lean? I've yet to get an EGT/boost gauge setup, so I have no idea where they are reading. Only time I've ever noticed smoke was when it's really cold, on (finally) starting, there's a very small amount of smoke for about 10 seconds or so..

I can only say that the dead stop acceleration is not unlike a 1985 honda accord automatic, if that good. From a roll, the old honda would probably take the Cummins from 20-70, rather easily. In my mind, this is quite unacceptable.

Thanks for listening/reading.

__________________
'96 RAM2500 CTD SCLB 4x4 Auto, 3.5:1 D70 LSD - BHAF, KDP fix, catless 4" with turn-down after the cab, 3K GSK, #10 torque plate, boost/pyro gauges, 5th wheel setup, Pioneer cd player, crank-em-up windows - otherwise, it's a boner-stocker

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Last edited by Rogan : 10-20-2009 at 06:22 PM.

[RPegram]

These trucks bone stock really are not powerhouses. They have the ability to do awesome work though. A few things to do and costs less than $125. Get a set of 3000 Governer Spring Kit (GSK) and install them. While installing them go ahead and slide the AFC full forward, and give the starwheel a few strokes. The 3K GSK will let it fuel all the way up to 3000 rpm. Yours currently starts defueling shortly above 2000. Sliding the AFC cover forward allows quicker throttle response. The starwheel gives her a little more fuel prior to the turbo kicking in. Spinning the starwheel will also cause the turbo to spool a little faster. None of these mods will affect the trans. You can do more, but your stock trans is not going to be your friend long. I did all these on mine and she will get up an go much quicker. I had it even turn the tires over the other day. If you crank the starwheel too much, you just end up with a big cloud of black on take off. These trucks are very well detuned from the factory for emissions controls. The changes you are making are what cummins intended for this engine to do.

__________________
'96 Dodge 3500,KDP killed, boost-pyro-trans temp, not stock anymore
'01 Dodge 2500 4X4, EC, LB, 6 speed, FP-pyro-boost,
'97 Chevrolet Suburban, K1500, 4.10 gears

[rallye12ctd]

RPegram is dead on. My '98 is pretty boring to drive in it's current stock form. I'm saving money to do mods. Basically, stock trucks are as fast as a school bus. Mine doesn't blow any smoke, and I have the same setup as you. BHAF and no silencer ring. That's it.

Unleash the potential of your 12 valve!

__________________
98 12 valve 5 speed. Longbox. BHAF. Silencer ring gone. Stock otherwise.

[Rogan]

Originally Posted by RPegram

These trucks bone stock really are not powerhouses. They have the ability to do awesome work though. A few things to do and costs less than $125. Get a set of 3000 Governer Spring Kit (GSK) and install them. While installing them go ahead and slide the AFC full forward, and give the starwheel a few strokes. The 3K GSK will let it fuel all the way up to 3000 rpm. Yours currently starts defueling shortly above 2000. Sliding the AFC cover forward allows quicker throttle response. The starwheel gives her a little more fuel prior to the turbo kicking in. Spinning the starwheel will also cause the turbo to spool a little faster. None of these mods will affect the trans. You can do more, but your stock trans is not going to be your friend long. I did all these on mine and she will get up an go much quicker. I had it even turn the tires over the other day. If you crank the starwheel too much, you just end up with a big cloud of black on take off. These trucks are very well detuned from the factory for emissions controls. The changes you are making are what cummins intended for this engine to do.

Awesome, thanks for the info.. where's the 'best place' to get those springs? (i cant believe i actually asked that.. )

As for sliding the AFC, just slide it fully toward the firewall or radiator?

how will the trans hold out with these few mods? I ask, because I just went through a trans replacement in my '97 Grand Cherokee V8 (44RE) and it was a total PITA, not to mention expensive (roughly $2K with me doing 100% of the labor, on my back, in the driveway, with hand tools...) I can only imagine how expensive this transmission is.

If it comes to that, I'll possibly go for a 5spd swap. I pull a 26' enclosed car trailer at about 7000lb gross, through the mountainous roads, here in western Virginia (not to be confused with West Virginia.) I'd rather have a stick trans, anyway, but this was a good deal, price-wise. Has the typical '95 paint flake issue, and both doors are rusted in the middle, bottome edge.. Body is irrelevant to me at the moment, though. Doors are easily replacable. I just want it to run a little stronger, before I hitch up to the trailer with it.

__________________
'96 RAM2500 CTD SCLB 4x4 Auto, 3.5:1 D70 LSD - BHAF, KDP fix, catless 4" with turn-down after the cab, 3K GSK, #10 torque plate, boost/pyro gauges, 5th wheel setup, Pioneer cd player, crank-em-up windows - otherwise, it's a boner-stocker