Low end power

[texas503]

I recently bought a 1997 auto Dodge cummins with #0 fuel plate full back, AFC full back (towards cab) 3000 GSK and 15* of timing. I have tweaked on the star wheel a little bit. My question is I have a 1999 24valve cummins auto with RV 275 injectors that has alot more low end power than this 12 valve. Is this normal? The 12 valve will run off and leave the 12 valve in upper RPM's but not down low. Is this normal due to variable timing and slightly larger injectors of the 24 valve? My 24 valve would really light the turbo at about 1200 rpm but the 12 valve won't until about 1600 rpm.So far the 24 valve is the better tow rig just because of low end grunt. Any suggestions?

[ISX]

Pushing those towards the cab defuels it.. Push the plate at least to the middle of the travel and push the AFC all the way forward (towards the radiator). The starwheel is centered in the hole stock, you want to turn it so that it threads towards the radiator, whichever way that may be, you just have to crank on it a bit and you'll see which way the starwheel is going. It will go all the way until you can't even see it. Then it should have some low end power. Change the fuel filter/air filter set your valves at 8/18 and it will smoke a 24V off the line.With a #0 plate you should definitely have an EGT gauge as well as knowing that if the auto is stock, it won't last long with that much power going to it.

[texas503]

Well that is kind of my problem, I really don't want to smoke a huge amount. I have not tweaked on the fuel plate or AFC as far as sliding it forward. I have left it as I bought it. I am worried about getting EGT's too high while towing. I have turned the starwheel out about 3/4. My tranny has a Goerend TC and valve body.Would you suggest a different fuel plate? It has what I bought the truck with. Will a different fuel plate give me better EGT control while better low end power? Thanks

[ISX]

Well that is kind of my problem, I really don't want to smoke a huge amount. I have not tweaked on the fuel plate or AFC as far as sliding it forward. I have left it as I bought it. I am worried about getting EGT's too high while towing. I have turned the starwheel out about 3/4. My tranny has a Goerend TC and valve body. Would you suggest a different fuel plate? It has what I bought the truck with. Will a different fuel plate give me better EGT control while better low end power? Thanks

The #0 plate is as close to running no plate as it gets.. Meaning it is the most fuel you can get with a plate still in it. You might leave it alone and just mess with the AFC as AFC stuff will most likely not do any harm. If you lug it and floor it then EGT can get up there but having an auto it will kick down so you don't really have that problem. What do you mean by out 3/4? The plate really only determines fueling when you have boost built and are getting on it pretty good, it's kinda a virtual block under the pedal. Low end power relies a lot on the AFC settings so it is going to be where most of the concern lies. I have no clue how good autos are so am not sure what exactly it could handle with that mod.

[texas503]

I have the star wheel adjusted about 3/4, maybe less, toward the radiator. It does not smoke unless I really get on to it and it still does not pour smoke. Do I need to adjust it out some more? Is it going to affect my tow ability, or is it controlled by my right foot more than anything? The truck has plenty of top end power, just wanting some more down low, but don't want to roast EGT's either. Maybe I am asking too much.

I used to have an Edge EZ on the 24 valve with the RV 275 injectors and it really did well down low. I am not expecting that kind of low end power, or should I?

Thanks for all the help.

--- Update to the previous post...

I do have boost, EGT, and tranny temp gauges; BHAF; 3.55 gears; 2500 4x4. I also have lock up switch for tranny.

[ISX]

I would keep turning it in then. Your foot will control the smoke if you let it, I took my AFC and plate completely out so I rely solely on my foot. So I say turn the starwheel all the way towards the radiator then let your foot and the amount of smoke be the judge. The AFC only comes into play at 5psi or less depending on where the starwheel is. It is only there to prevent smoke before the turbo can build enough boost to clear the smoke up, so it really only plays a role when you're taking off or in low boost RPM conditions. Tightening the valves will help, putting a straight pipe on it will help. Also make sure the fuel and air filters are good. You might need to check fuel pressure to see if the overflow valve is weak and causing low fuel pressure which will hinder power. This requires drilling a tapping a banjo bolt..

[texas503]

Just one more question. The truck just got the timing put to 15 degrees or supposed to be at 15 degrees. It sounds alot different than a friend's 96 that has not had timing adjusted. My truck almost has a valve rattle sound. Sort of a higher pitch tinking, rather the mello sound of my buddy's. Is that normal with 15 degrees timing? Is does not have a lope unless it gets idled really low.Thanks once again.

[ISX]

Yeah the more advanced the timing the more it will knock. If it isn't at 15 degrees and somehow is advanced more than that, low end power WILL be sacrificed.

[texas503]

Sorry, but can I ask ONE more question, since I am new to 12 valve? My truck has white smoke while idling. Not any major smoking but a haze. It seems to do it worse when cold start up but seems to smoke a little all the time. Is this normal or...The exhaust smells alot stronger than exhaust from my 24 valve, I can even get a wiff of it while sitting at a stop light sometimes and most definately when I step out of the truck. Does that mean bad injector?Seems to have started after timing bumped up. Could it be a head gasket, but not leaking any fluids. Or could the timing be too much, too little.So support the injector theory, could that cause the clanging noise? I also had valves adjusted when timing was done.Truck runs O.K. and I just got 22 mpg on a highway trip babying it.Maybe I am just paranoid.

[ISX]

Advanced timing will make it smoke at idle because it is injecting the fuel before there is enough heat to burn it off as well as if it were more retarded. As RPM goes up and the pistons move faster, then the advanced timing helps to get all the fuel in before TDC. At idle it is getting the fuel all in a fair amount before TDC and causing a little bit of backlash even. It knocks more because of that. 24V's are VERY advanced in the winter or so Mike tells me, that is why they knock so loud. It could also just be a sign of high miles (not sure how many are on it). Timing really does play a big part in it though, mine smoked any time the engine wasn't up to temp.Here's mine at 56F in the morning when it was really advanced.

[texas503]

Thanks so much again. Than reassures me. Just out of curiosity what was your timing set to at the time of the video?Mine does not smoke quit that much. But it seems to smoke slightly even when warmed up.166,000 miles, so that shouldn't be an issue.

[ISX]

Yeah you could try cleaning the injectors. I clean them every 5000 miles maybe less. I can't resist cleaning them cause they look so perdy when I'm done I do the valves just as often. I don't exactly know what the timing was but you can see it starts like crap so I'm guessing over 20*. I had a guy do it who said he knew what he was doing but all he did was guess that it was at the stock 13* and he popped the gear off and turned the engine a little then put it back on. Hence the reason I really kicked it into gear to learn about these and I started tearing my truck apart daily. It would flat out NOT start under 20F without running the grids multiple times, even then my ford could top it.

[texas503]

Well I found out how they did the timing. The guy at the shop said they pinned the pump at TDC and then loosened the pump and turned the engine 15 degrees on relation to the dampner. Does that sound right? I know the truck is alittle harder to start now that it's colder. It has gotten in the 20's degrees here in N. GA and when I start it, it will idle at like 300 rpm.When I asked him why they did not use the dial indicator he said that it was not very accurate. He said they recently had a guy bring a truck in that had gotten his timing way out by using a dial indicator.What do you think?

[ISX]

Well I found out how they did the timing. The guy at the shop said they pinned the pump at TDC and then loosened the pump and turned the engine 15 degrees on relation to the dampner. Does that sound right? I know the truck is alittle harder to start now that it's colder. It has gotten in the 20's here in N. GA and when I start it, it will idle at like 300 rpm.

The pump is calibrated so that it is ONLY able to be pinned when the engine is at TDC. This is where the pump is actually at the timing specified on the cummins data plate. Your's might say 12.5-13.5*, which means when you get the engine to TDC, you should be able to lock the pump, if you can't lock the pump, the pump is out of time. There is a little flat bladed screwdriver looking thing that comes into the locking window on the pump ONLY when it is at the predetermined factory timing. Meaning if the engine is at TDC and the pump is stock, that thing should be perfectly centered in that window. If it is not, then the timing is not stock. If they locked the pump at that spot and then turn the engine 15* backwards, then you actually just added that to the stock timing, meaning 12.5(or 13.5*)+15=27.5*. This means you are at that 27.5*(or 28.5*) and is why it starts like crap. If you want to do it that way (which is crude at best), you would turn the engine until that window shows the locking flat bladed thing, then lock the pump, then loosen the nut, then rotate the engine to TDC compression/power #1. Then rotate the engine backwards the difference of the degree you want because you are already at the stock timing (12.5 or 13.5), so if you wanted 15*, turn the engine backwards another 2.5-1.5 damper degrees and then you will be at 15* timing. Basically the start of injection happens at 12.5 or 13.5* BTDC. That bladed thing in the pump I guess called the timing pin is set so it will align when the engine is rotated another 12.5-13.5* so that you can easily time the engine based on TDC which is easy to find. The hard though maybe more correct way would be to get to the start of injection then rotate the engine to the desired timing BTDC. Technically you could rotate the engine backwards 12.5-.13.5* from TDC , and you should be at the start of injection if the timing pin lined up at TDC of the engine, so then you could loosen the nut on the pump and rotate the engine to wherever you wanted timing to be in relation to TDC, so 15* BTDC, then tighten that nut and it should be timed to 15* TDC. Keep in mind this is extremely crude..ideally you should be using a dial indicator to adjust timing as shown here. http://dodgeram.info/tsb/1994/18-10-94a.htm This might help you, along with showing the flat bladed screwdriver thing (last pic). http://articles.mopar1973man.com/index.php?option=com_content&view=article&id=19:p7100-injection-pump-confirming-stock-timing&catid=8&Itemid=106

[texas503]

So I should probably find someone to at least confirm the timing using a dial indicator. That is what it sounds like, I may actually get them to turn the timing down at bit, I don't like the lack of low end power it has now, I seem to spend quite a bit of time down low.

[ISX]

So I should probably find someone to at least confirm the timing using a dial indicator. That is what it sounds like, I may actually get them to turn the timing down at bit, I don't like the lack of low end power it has now, I seem to spend quite a bit of time down low.

At 27* you won't have anything down low. I would put it to 14-15 and that will be perfect. Over 15 is for people who tow a lot (spend a lot of time higher in the RPM's). Over 18 is for people with 4.10's who think they have to go 100mph. Over 20 is for pullers (4-5k RPM). Mine is at around 14.5 and it's perfect for me.

[Ldrivon]

I bought a timming set and barring tool from Snapon. Timming is set at 15 = 5.4. I noticed better all around power.

[texas503]

Well I got my timing checked again and they said it was at 15 degrees, but the mechanic said he thought is running rich, which you can smell almost an unburnt fuel smell along with the white smoke. He was saying that it was running rich due to the timing being bumped up, but I didn't think 15 degrees was all that much. I was wondering if maybe I have a worn injector who's pop off pressure was off and injecting too early causing the unburnt fuel? I won't think that I have low compression at only 173,000 miles? Or a bad injection pump? Would 15 degrees really cause white smoke and unburnt fuel?Thanks

[ISX]

How did he check it this time? The way you said he did last time is completely wrong. 15 degrees won't cause it to run much different than stock. Your symptoms are classic overly-advanced timing which means you really need to figure out exactly how he is checking timing.

[Mopar1973Man]

I tend to agree with ISX on the white smoke issue... :smart:But to open the door in both directions... You could pull all 6 injectors and have them pop tested to verify they are working properly. But then returning back to ISX ideas yes if timing is truely off then the white smoke will be more dominate at cold start up and have a foul smell of unburnt fuel because typically it retarded.