You think a Timbo APPS will correct this surging issue?

[BioHazard2222]

I have recently bought my first Dodge Cummins, I have been a ford guy prior and am retiring my 1993 7.3L F350 with 330k miles on it.

Anyway my pickup is a '02 4X4 5-Speed, all was well for the first week or so that I owned it then it started to the this surging thing, it usually surges between 1500-1900rpm, under load, like accelerating or going up a hill, sometime way worse than other times.

[*]I don't show any error codes with the ignition switch way of looking

[*]I have reset the APPS

[*]I have cleaned my grounds

[*]Happens while both while using cruise control and not using cruise control

Seems like a Timbo APPS has fixed things similar to this for others, just wanting to get some other folks opinion about if they think this could be APPS related or not.

Or other ideas of what may be the cause?

It looks like I'm not alone with this type of problem, seems to be many threads about it, I have tried to read most of them, but I'm still not sure...

Any help or ideas would be appreciated.

[jp4bigblue]

I had a similar issue and I put a new fuel filter in and it helped alot. I am also new to these trucks..its worth a try and won't cost you much.Also people will probably ask you if the truck has a fuel pressure gauge and what it reads under WOT.Jason

[CSM]

I would be concerned with fuel pressure or a lift pump on the way out. If it were an APPS I would think it would do it consistently at an RPM, not so intermittent. Even my FASS or Air Dog will do that though if the filters are dirty enough and I see a pressure drop at high flow rates.

[BioHazard2222]

I will change out the filter tonight or this weekend and see if that helps... I was told it had been changed recently, but who knows... if I change it then I will know for sure...Sorry if its a stupid question, but as far as a fuel pressure gauge, what are most people using? I have not ever checked fuel pressure before. is the type of gauge and where to hook up pretty self explanatory?Open to any and all recommendations...

[dobienut]

Mine surged mainly when cold, or when out on the highways trying to hold a constant speed. Difference in mine from yours is mine did not do it when I used cruise control. Tim from Timbo Apps if I remember correctly said the ECM controls the throttle when using cruise, and where mine did not do it when using cruise, he felt the Apps sensor was the culprit. I bought one and put it on, problem solved...yours on the other hand may be a different beaast from the sounds of things

Fuel gauge can be anywhere from an electronic programmer with display screen, or mechanical gauges. You tap into the fitting going into your VP44 that feeds the pump, use a snubber or T- valve to restrict the pulsations that will ruin your gauge over time. I had a cheap $15 gauge until I got an Edge monitor...did the trick and showed what I had for pressure until I got a good one. A 30psi will be best as you hope to run around 12-19 psi for pressure.

[jp4bigblue]

This is the help I got a few weeks ago.... http://forum.mopar1973man.com/threads/6171-fuel-gauge Even if you dont put a mechanical gauge in I recommend putting in the vulcan big line kit, the line going from the filter to the injection pump is so small. From what I have read most people say that putting a fuel pressure gauge on your truck is very important because the stock lift pumps are crap and kills the vp44. So even if your problem is not fuel pump related it is a good investment to get that fuel pressure gauge on.

[dripley]

Mine surged mainly when cold, or when out on the highways trying to hold a constant speed. Difference in mine from yours is mine did not do it when I used cruise control. Tim from Timbo Apps if I remember correctly said the ECM controls the throttle when using cruise, and where mine did not do it when using cruise, he felt the Apps sensor was the culprit. I bought one and put it on, problem solved...yours on the other hand may be a different beaast from the sounds of things

Fuel gauge can be anywhere from an electronic programmer with display screen, or mechanical gauges. You tap into the fitting going into your VP44 that feeds the pump, use a snubber or T- valve to restrict the pulsations that will ruin your gauge over time. I had a cheap $15 gauge until I got an Edge monitor...did the trick and showed what I had for pressure until I got a good one. A 30psi will be best as you hope to run around 12-19 psi for pressure.

Dobienut is right about the cruise. It is controlled by the ecm and not the apps. That is a good way of testing, if you have a problem like yours with the cruise off, you can turn the cruise on and see if it goes a way. That would point to the apps. Seems yours is happening no matter which is running the engine.

Give the filter swap a try. There is also a test port on your vp where the fuel line goes into int. It is a schrader valve with a cap on it. You can hook up a test gauge there and see what your fuel pressure is now. but by all means start looking at a fuel pressure gauge in the near future.

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This is the help I got a few weeks ago.... http://forum.mopar1973man.com/threads/6171-fuel-gauge

Even if you dont put a mechanical gauge in I recommend putting in the vulcan big line kit, the line going from the filter to the injection pump is so small.

From what I have read most people say that putting a fuel pressure gauge on your truck is very important because the stock lift pumps are crap and kills the vp44. So even if your problem is not fuel pump related it is a good investment to get that fuel pressure gauge on.

Just to add to this, the fuel line from your tank to the filter is the same size also. All the fuel line on these truck is small. This is if you are still stock.

[JAG1]

I will change out the filter tonight or this weekend and see if that helps... I was told it had been changed recently, but who knows... if I change it then I will know for sure... Sorry if its a stupid question, but as far as a fuel pressure gauge, what are most people using? I have not ever checked fuel pressure before. is the type of gauge and where to hook up pretty self explanatory? Open to any and all recommendations...

This forum's unwritten rule is there are no stupid questions. Most on this forum are always more than willing to help. My gauges were bought and installed by Source Automotive after making the mistake of having the dealer put in some inexpensive ones ( at first, I thought they were great). Source Auto is (503) 654 9004. Those guys are good to buy from, ship anywhere, and sell you all the right stuff. BTW, Vulcan Performance is very good also for gauges and other items. I give both my business often. my gauges with the cool blue background lighting are H.I.'s. They work great.

[Mopar1973Man]

This forum's unwritten rule is there are no stupid questions.

So absolutely correct! The only way for you to learn more is to ask questions.

[BioHazard2222]

So I just changed out the fuel filter and it still surges... I noticed that when it surges, if I hold the throttle open at the same point and watch my passenger side mirror, I see that most of the time when it surge, it puffs a little bluish white smoke... It only does this when it is stuttering hard... Any ideas?

[Mopar1973Man]

Time to check error codes and fuel pressure...

[BioHazard2222]

Well... I figured it out... Someone before me put an inline fuel filter on the hard line between tank and engine, just a 3/8" inline filter. I replaced that and it runs better than it ever has (Since I've owned it, only a month or so)I was really starting to get worried, I went to town twice this weekend (30 mile round trip) and wasn't sure I was gonna make it back, my pick up was bucking and snorting and coughing up smoke and not throwing any error codes...Anyway, thank you to all who helped out!Now on to some mods...I think the next thing is air filter, the previous owner put on a Spectra filter and just sat it in the bottom half of the stock air box, so I need to fix that, probably BHAF is what I'm thinking, i'll need to do some looking to see what the best option for air box with the BHAF is...Anyway, Thanks again!!!

[jp4bigblue]

Well... I figured it out... Someone before me put an inline fuel filter on the hard line between tank and engine, just a 3/8" inline filter. I replaced that and it runs better than it ever has (Since I've owned it, only a month or so)I was really starting to get worried, I went to town twice this weekend (30 mile round trip) and wasn't sure I was gonna make it back, my pick up was bucking and snorting and coughing up smoke and not throwing any error codes...Anyway, thank you to all who helped out!Now on to some mods...I think the next thing is air filter, the previous owner put on a Spectra filter and just sat it in the bottom half of the stock air box, so I need to fix that, probably BHAF is what I'm thinking, i'll need to do some looking to see what the best option for air box with the BHAF is...Anyway, Thanks again!!!Well man I am glad you got it figured out and glad it was an easy fix. Also thanks for telling what the problem ended up being. So many times I read through a thread trying to figure out a problem with my truck and get to the end of the thread and the guy who asked for helped never came back to say how he end up fixing the problem. So thanks for that.Jason

[Mopar1973Man]

Still check the fuel pressure... I'm really worried now that there is a inline filter and it possibly cause problems for the VP44.

[BioHazard2222]

It looks like there may have been something mounted on the frame rail where this inline filter is, but I don't know what should have been there... it is about 18" in front of the tank on the inside of the frame rail... any ideas?

What do you recommend for fuel pressure gauge? I bought a WiFi OBDII Scanner to hook up to my iPhone, but apparently the fuel pressure part of the scanner does not work for Diesels or something, because it shows N/A.

Is there a simple solution you would recommend?

Thanks!

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Still check the fuel pressure... I'm really worried now that there is a inline filter and it possibly cause problems for the VP44.

Im also curious why you think this would cause problems with the VP44?