BigBlock

I need alittle help. I am disappointed in my truck so far. I still have alot of faith in the Cummins Motor but I have a very frustrating low power issue.I just bought the truck and drove it approx 900mi from Houston, TX to Albuquerque, NM (RELATIVELY FLAT LAND). It felt very strong on that first trip.

Well about 3 weeks ago I hooked up a 10' flatbed trailer and loaded it with just furniture(no more than 1500lbs) headed to Phoenix, AZ. Well it does OK in 1st 2nd and 3rd and pulls hard to cruising speeds, but once you hit a hill(or any kind of incline at that) in 4th of 5th forget about it. The best I could do was approaching a 6% grade at 80mph and apprx 2200 in 5th, I had to down shift to 4th while the RPM's dropped to 1900 and would just sit there(working HARD!!) at about 55MPH, with the throttle pinned. Then the second I let off the throttle the slightest bit I would loose speed and it was over, I would have to downshift to 3rd unable to regain any of my speed. I just gave up and cruised at like 40MPH. It even has trouble unloaded, unable to keep speed in 5th gear.I am not too fond of lugging my motor. OHHH Fuel(sorry) Mileage SUCKS!!! 13 TO 15mpg loaded or un-loaded. At times I find myself hitting the steering wheel. HOW ARE YOU GUYS PULLING 12,000lbs+???

It seems as if ,too great of a load is put on it, it says
"F#$K IT" and gives up. I tried the simpler stuff first in an attempt to fix it (Air Filter, Fuel Filter,adjusting the valves, etc) But to no avail. My next step was to check the timing. The CAT also looks like it is about to fall off . Now I know that the 35" tires don't exactly help, but when I spoke breifly to Cummins and explained my situation they agreed that I should have no Problem-O pulling that little trailer up that grade.This is my first Cummins and really have no feel for how much power the stock 12 valve is supposed to have. Any one who still owns a Completely STOCK 12Valve? What do you think? Any suggestions or help would be greatly appreciated. Also does anyone in the Albuquerque Area have a KDP jig that could lend me a hand in fixing my KDP.
Thanks in advance!!!

95ramtough

I have the exact same truck as you, with different tires and no lift. I have 33.5&quot;tall tires but only10&quot; wide. I can pull any hill on the freeway up here in the mountains at 80mph, let off the throttle all the way and it will still jerk my head bak when I hit the peddle again. I would say start by changing the air filter, fuel filter... I have heard that the timing could need advanced or adjusted... I am not too knowledgable about these CTDs yet, but I am sure some guys will reply with great information. Your truck does not sound right though, I get about 21-22 on the highway, 17-19 in town. Good luck!<br><br>Mike

pappyman

With a lite load like that something is wrong :-[ since your stock Iam guessing you have no gauges either...my first guess is your timing is off since your fuel mileage is low too (not gas mileage)...my advise is have your timing set to 15.5-16* then get some gauges and for some cheap horsepower put in a fuel plate....this should wake up your engine and improve your mileage

boughtadodge

First thing I would check is your cat it sounds to me like it might be plugged then check fuel pressure. I have heard that there is problems with a flow valve {or what ever it is called} in the pump that can cause low power also. Matt

Don M

You have a very poweful combination of parts in your truck. Even stock my truck would pulll heavy trailers at altitude without any troubles. <br><br>Check your fuel pressure first as eluded to earlier. At idle it should be around 20-25psi. Reved up in the garage/driveway it should be about 35-38 psi. Checking the pressure requires a fitting you can install in the fuel filter housing from TST products and a gauge of some sort to connect it all up. Many guys just use their boost gauge as a quick way to check the fuel pressure.<br><br>Timing generally will not slip in a stock truck, but it can happen. You rtimnig is factory set at 13.5 degrees. You can bump it up to 16 without any negative effects on power and it will actually help the EGT's and fuel milage some.<br><br>You may also have a leaking wastegate actuator or a boost leak somewhere in the truck. Check the intercooler hoses to make sure they are all tight and not leaking. <br><br>Like I said earlier, this particuar engine will have more than adequte power to pull a trailer at any speed you can drive without running off the road.<br><br>A little bit of tweaking will net you better mileage and even more power. Too bad your not in the Dallas area, I could help hands on.<br><br>Don~<br><br><br>

BigBlock

Well, decided to go to a diesel Repair shop today to get some more advice and they told me I had a very sick diesel on my hands ???. They really didn't do much diagnosing but I took them on a ride up Nine Mile Hill(big hill) and showed them exactly how much power I had. He then took me on a ride in another &quot;SICK&quot; cummins that had already had a mild fuel plate and injectors on it. That sucker pulled up Nine Mile at 90mph max. (4.11 GEARS) It pumped tons of black smoke and was FAST!!. I was impressed, from reading through this site and driving my truck, I got the impression that the 12 valve dodge was not a quick truck,unless it was bombed. <br><br> He recommended pretty much the same things: Recheck my valve adjustments, Check the timing, Check all my turbo clamps, Check the fuel pressure, and last but not least make sure my waste gate was not stuck open. However they are not cheap $70/hr. And just Checking the timing is an hour job.<br><br> How would I go about making sure my waste gate is not leaking or stuck open? What are things to look for? Pics would help if anyone has them. <br><br>THANKS GUYS!

Smokee

For the waste gate, try pinching off the rubber line that goes from the AFC to the turbo, between the valve covers. That should give you boost.
On my stock engine, the fuel plate had been installed at a slight angle. Although the truck ran well, it would not pull hard with any kind of load. The DC mechanic worked on it over and over, retimed, etc. and made great improvements...however... it never really got completely better.

One day I decided to look at the fuel plate. I saw that it was cocked, slid it forward, and low power isses have been history ever since.
george

cwbronc

BIGBLOCK, I know exactly what you're saying. I recently bought a 95 12v with 120k and 4.10 gears. I don't have any power either. In the past couple of months it has gotten worse. It started out that I didn't have much power, then I wasn't able to go 60-65 up a hill. I spoke to RAMMIN ON from this site, and ended up having him change my injectors (and fix my KDP THANKS AGAIN!!) It seemed to run better for a day, then it was worse than ever. I noticed it smoking and running rough up hills, and even a couple of times wanted to stall out. I couldn't really see the color of the smoke too well so I assumed it was burning oil. I checked later on and I hadn't used any oil. After that I spoke to RAMMIN ON again, and he said it is probably the injection pump :'( Well for now since I'm in college I have found other means of transportation until I can afford the repairs. I'm stumped, but just from looking on the site maybe it's just your lift pump? I'm still new to the CTD so don't know much. Sorry to hear about it. Cwbronc

BigBlock

Smokey,<br> Just to clarify the line you are talking about starts at the very back of the AFC housing as a big rubber hose and between the valve covers turns to metal tubuing and runs to the head of the wastegate. Exactly how would that give me boost if that is the problem? <br>thanks

dodgeman01

by clamping that off it will let your waste gate stay closed longer. Therefore you would build more boost<br>I think thats how it goes.<br>DM01

BigBlock

Well, I clamped off the hose that runs to the wastegate (Will this hurt my turbo??) and noticed a moderate difference in acceleration above 1700rpm and a huge difference over 2200rpm to 2600rpm. What does this mean??? The truck accelerates much faster now. However I don't think that is the whole solution. It is good on flat terrain but going up a hill in fifth the RPM'S still drop off rather fast. I hear more chattering or clicking under load.(Maybe I didn't do the valves right). I now see I have some white smoke. Any advice now???? [undecided]<br><br>I now want to have my timing checked and fuel pressure checked.

pappyman

White smoke after the engine is warmed to operating temp could be<br><br> Coolant temp is below specs or the intake manifold air temp is below specs. <br> Poor fuel quality <br> Fuel injection pump timing is not correct <br> Injector sealing washer not correct <br> Injectors worn or malfunctioning <br> Coolant leak into the combustion chamber <br> Fuel injection pump is malfunctioning. <br><br>

turbo thom

BB:<br> If you see the brass elbow on top of the pump, follow it to the wastegate acuator. When that fitting is replaced for more boost, when a plate is installed, it restricts air flow to the turbo. Build more boost before working the wastegate. The low power to me sounds like a boostleak. The one thing I did to my truck that really woke it up was the governor springs. I now run a 14cm2 non/wastegated housing and get about 44 lbs of boost. <br><br> A few things I would do is check the turbo hoses for any loose clamp and possibly a free flowing intercooler. What RPM is the engine defueling? I towed with mine stock for 3 years till I got to &quot;upgrading&quot; it. I pulled 14K and it too would slow down on hills. Now a hill is just the same as the flat land. Go slow with the parts you install and know where you left and where you want to go. Injectors by themselves will not give you the results you're looking for unless you burn the extra fuel. There is the rpm and timing. Just be very careful with what you add and remember the results. Some things may not work like you expect. And study, study, study.<br><br>..Preston..

BigBlock

turbo thom,<br> By defueling you mean when the trucks power starts to fall off. Right?? My truck seems to accelerate the most from about 1650rpm to 2100rpm and then just kinda drops off(when that tube thingy is unclamped) after I clamped the tube, It pulled nicely to about 2600rpm but still had a problem under a load(big hill) and is really chattery, which leads me to believe something else is also wrong. Maybe Lift Pump.

turbo thom

BB:<br>By chatter do you mean &quot;valve chatter&quot;? Have you adjusted the valves? That will affect the way it runs. Most 12V's I'm familiar with defuel at around 2600. It just seems to quit on you. If you do the governor springs , AFC spring and adjustment, ,you will see a tremendous difference. With the 3K G springs I turn up to 3200 , and could get more.<br><br> Just remember to have a base line to judge from to know how far you have gone.<br><br> I installed the 300 injectors first and saw a little increase but &quot;not enough&quot;. With the increase of rpm and timing, then you can burn the fuel. Now comes the plate to match the 370's you got. With the power now you got a bunch of EGT's to displace. It just never ends, does it? ;D<br><br>..Preston..