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2001 Stock 24v Fuel/Surging Issues

17K views 39 replies 7 participants last post by  82Dodge331 
#1 ·
I’ll try to keep this short and coherent, since I got a bit of info.
Truck info: 2001, 3/4, 4x4, auto, 247k miles, FASS DDRP, 5in. straight exhaust, I bought truck 3 months ago, VP-44 was supposedly replace within last 3 years (the amount of time prev. owner had it), no aux. gauges (no time or money yet).

Problems:
-I have always felt a very slight surging/lopeing under little throttle. Runs great through mid. throttle. Power falls off at high rpm, but I think that would be normal for stock engine.
-Didn’t know bout ¼ issue, I ran it out. Filled it, primed it, started it. Hard starts once in a while now.
-Return line from IP to the tee broke. Fixed with fuel hose and clamps, may leak a bit still. Hard/smokey starts once in a while. If I cycle “wait to start” 3 times has easier starts.
-Started to surge at idle once in a while, not a lot. Does it cold or hot, then will stop after driving it or won’t stop.
-Changed oil, oil filter, and fuel filter (stock). Still all same problems.
-Did 3-key code trick: PCU - P1693 and ECU – P0234. Both are boost related. P1693 is companion code. Got crappy code reader, it won’t stay linked to truck, can’t read codes or even truck ID. Linking prob. may be symptom?

Questions: So I have the ¼ tank issue, hard/smokey starts once in a while, surging under little throttle, surging idle once in a while, codes P1693 and P0234.

-Could my IP be going? Was told was new, and looks to be as well. I don’t know if it’s the newest version with the upgraded parts.
-Could replacing my LP help? Or what can I do fix the ¼ tank prob.? I want to keep DDRP and no tank sumps. What’s the big line kit, model or part number? Raptor 100 or 1000?
-How many fuel pumps does my truck have? I’ve see people talk about an in-tank pump, but don’t know if mine has one. Could I put one in? Or I don’t need it?
-What’s the APPS, never heard of it before? Reset procedure? Replacement cost? Would my truck have a TPS, could that cause these probs? Also, cam sensor, could cleaning that help?

I’m sorry for the long post and all the questions. It would help if the cheapest and easiest solutions were listed first, then I can eliminate them as I go. Then I will try to update on what I’ve done as I do it.

Dec. 7, 2016 – original post
Dec. 12, 2016 - APPS reset, will update after few days of driving
Dec. 16, 2016 - APPS reset didn't work, back to surging/lopeing issue, except now it will do it in gear while at full stop, before only did it in neutral or park.
Dec. 27, 2016 - Truck will now lope, hard, in Park, Neutral, and in Gear at Stop. Had a couple hard starts for first time in few weeks. And fuel gauge showed no fuel for about half hour one day.
Dec. 28, 2016 - Have been having some really hard starts lately. Took half hour first time, had fuel, had charge, cracked easily, it wasn't even as cold as it has been lately. did it to me again today, I noticed the Wait light went right out after I turned key to ON. so I cycled the key a couple more times as I always do. wouldn't start. so I bumped it then let it set and I could here the LP going, then stop. I hit the key and it finally starts. Could this be a sign my IP is going, or LP? And why'd my Wait light go out so quick?
Jan. 15, 2017 - Changed the alt to a 180 amp Nations unit, no big changes. Will install big line/LP relo kit soon.
Jan. 22, 2017 - Installed full big line kit and LP relocation kit. No change from alt install. Still has tough starts, and white smoke. Will check for leaks again.
 
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#2 ·
The P0234 I believe is a turbo overboost condition. Is your wastegate working properly? I don't know where the DDRP but I believe it's still on the block down by the starter. Check down there to see if you see one. If not, look on the frame rails leading to the tank. This is where most pumps are located. But it is possible to have an in-tank pump. Probably not likely. It should only have one LP though. Idk if it would help you, but if you do replace the LP, I would go with a FASS. The APPS is the accelerator pedal position sensor and can cause weird erratic idle or a dead pedal. The APPS can be a little expensive. Maybe 100 or so. I don't remember but only certain years have a cam sensor or a crank sensor. These usually would present with a no start conditions. Hopefully someone more experienced will chime in


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#3 ·
My surge was due to apps sensor. i got the Timbo apps sensor and it solved it. Try doing the reset first. Disconnect battery's for 30 mins. Reconnect and slowly push gas pedal to floor and slowly release. Then start truck.

Also need a fuel pressure gauge. Genos garage sells them and they are easy to install.

Hard start normally has to do with air getting in the system somehow. Make sure you aren't dripping fuel out of one of the fittings somewhere

I have the ddrp also. It is mounted to the block. Look below the fuel filter and you will see it bolted to the frame. A hose runs from it to the bottom of your fuel filter housing.
 
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#4 ·
thanks freelove33
I haven't checked the waste gate yet. I know the where DDRP is, right on the block where the Carter would be, and still uses factory fuel filter. I wont be replacing the DDRP for cost reasons, and I don't like the idea of a fuel tank sump, then what would my options be for fixing the 1/4 issue?
Also, do any Cummins trucks come factory with an in-tank pump (1st, 2nd, 3rd or 4th gen, any?), or is this an aftermarket thing?
thanks GavinTrey,
I will try the reset as soon as I can. and I know I need gauges, no time or money though... yet. I figured im probly sucking air some where, just gotta trace it. does any one have a better tee fitting, the tee where the return line from the IP and from the head meet and run back to the tank. that tee doesn't seem to have good sealing, id like to change it out with a better tee fitting.
 
#5 ·
Fuel sumps are great, but not needed. Especially with a DDRP. You could do a draw straw or just try cleaning out the factory pick up. My factory pick up will suck fuel until completely dry. As far as I know, the 1st and 2nd gens didn't come with an in tank pump. Not sure about the 3rd and 4th. They use the CP3 injection pump which is capable of pulling fuel itself. They are also used on Duramax which do not have lift pumps.


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#6 ·
I think what im going to do is relocate the DDRP, fab up a draw straw and do a big line kit... eventually.
As for now who else has ideas on how to fix my surging rpm problem?
 
#7 ·
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#8 ·
Return line leaks cause air in the system and no or hard start problems, that is it, not related to any of your other problems. Do you have a delayed wait to start light. If so you have a bad ecm and that is probably causing all of your problems. The ecm damage is due to AC issues from your alternator. Read up and deal with both.
 
#9 ·
thanks freelove for the APPS reset procedure.

bigfish, I figured leaky lines would be causing my hard starts. ill go through them when I relocate my LP, which Ill get to eventually. my "wait to start" comes right on every time, no delay. I just cycle it 2-3 times cause the truck starts easier than with just 1 cycle. I think I can rule out the ecm, for now.

so, draw straw and relocating my LP will solve my 1/4 tank issue.
tracing line leaks will solve my hard/smokey starts.
hopefully resetting my APPS will solve my surging problem.

thanks for the help, I know all this stuff has ben discussed before, but theres just so much info it can get confusing. I wanted as much info on my truck probs in one place.
ill update on what ive done and if they fix anything.
 
#10 ·
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#11 ·
Resetting the APPS and adjusting the APPS idle voltage are two different things.
What APPS did you replace, Factory, Timbo or other? Why did you replace it? Surging, missing, skipping, dead pedal etc? Do you know what idle voltage was set at?

Regardless of current ECM condition, Check for AC level from the alternator.
 
#12 ·
My bad on the reset. I tried finding the one on Moparmans website but it wasn't working for me [emoji28]

Bigfish, he hasn't said he replaced the APPS yet.


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#13 ·
OK. That was somebody that jumped on with similar problem of surging. In that case. What is the apps idle voltage on pin 3 output and does it graduate to about 4 volts at WOT? It still would not surprise me that he has an AC voltage isue.
 
#15 ·
no I don't have any TC issues, tranny shifts and locks fine, I do want to freshen it up soon though.
I just did the APPS reset, and it seems to feel a lot better, but ill give my full report after a few days of driving.
Q: IF I do have AC noise and it De-calibrated my APPS or whatever, and then I upgraded to a Timbo APPS, should I be worried that the Timbo will die also from AC noise? I've read the Timbo is mechanical so it shouldn't be affected by AC noise, right?

-thanks everyone for the help so far
 
#16 ·
I have my own issues with the Timbo, but you may be fine on your 01. The AC would cause other interference problems and damage the ECM and other things worse than the APPS. The AC should be monitored regardless of symptoms to catch it before it causes problems.
Resetting APPS is to sink it with the ECM is all.
 
#17 ·
Alright I will test for AC. Could someone link some info for me, background about it, why it happens, how to test and fixing it.
My APPS reset only lasted a day, its back to surging when it wants.
 
#18 ·
As far as I am concerned the Timbo apps idle voltage of .64 volts is too high and caused surging in my truck. Tried two of them. Went to Wells in Duralast from Autozone. Set at under .5 volts. Works perfect.
Search the following at the top this forum page, and non power train too:
AC sine issues
AC issues
AC voltage issues
Surging at idle
Wells tps
Wells apps

You will find several threads
Some will disagree with me on that one, but I tried two.
 
#19 ·
Alright I read through a lot of threads/articles and it seems these alternators are prone to having diodes fail. So, if I go and change the alt, with a good alt that's been tested, what's to stop that one from dying in a year??? And I don't have the money, not an extra penny, for a new alt, let alone an upgraded one.
- IF... I do get a new alt, that's been tested, A-OK, what's the life span I can expect from that alt?
- Can I upgrade the one I have with better bearings, brushes and better diodes, so this wont happen again for a LONG time?
Its just a shame that an alt that puts out good voltage is actually bad and needs to be replaced.
 
#20 ·
Alright I read through a lot of threads/articles and it seems these alternators are prone to having diodes fail. So, if I go and change the alt, with a good alt that's been tested, what's to stop that one from dying in a year???
After seeing multiple threads about alternators and A/C noise, I tested mine just to be sure.

My truck has the original alternator, and is still going strong.....
 
#21 ·
They are all mechanical devices and could last a month or 10 years. Part of the cost of doing business(driving). Some options, buy parts and rebuild yourself, Buy something new or upgraded and get it with a lifetime warranty so you can keep taking it back if bad. Don't buy Napa, I have been having trouble with several of them.
 
#22 ·
So buying the parts and rebuilding option, does anyone know if I can buy just the diodes? Are there any "upgraded" diodes out there?
 
#23 ·
I'm still trying to source out upgraded diodes that are possibly cheaper than LarryB's. LarryB's are right around 90-100 bucks the last I've seen for another 20 to 40 bucks I can buy an brand new alternator. I'm trying to find diodes that are design for high current flow rates possibly that exceed the 140 Amp max flow rate of our alternators.
 
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#24 ·
I just looked on LarryB's site, for the Denso diode pack comes to $80 with shipping and tax. More expensive than I thought, might as well spring for a new alt, but may be better to get new diodes that way I know they're right. What brand Alts do 24v Cummins have? LarryB mentions Bosch Alts as well. MoparMan, if you find some upgrades diodes I will be the first to buy, thanks.
 
#25 ·
Yes, just go to your local alternator/stater rebuild shop. They have them or can get them and will sell them usually.
Also google "alternator parts" There are several wholesalers/retailers.
 
#26 ·
Also google "alternator parts" There are several wholesalers/retailers.
Th only thing is finding quality alternator parts that are NOT cheap China parts. You want a quality diode rated for more than the alternator is design for. I' was attempting to source out the big over size diodes like use in Nations or MeanGreen alternators. Something that will be not working at 110% but something beefy enough to be at 60% and less likely to fail.
 
#27 ·
Several sources were listed. At least one I looked at showed several Standard Motor Company sources that were all well known American, German and Japanese companies.
You will have to jsut google it and check them out. I am sure you can tell the difference between good companies and fly-by-nights.
Keep in mind several companies on here are just repackaging somebody else parts, good and bad ones.
 
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