Engine/Transmission (1998.5 - 2002) Catchers and half throttle power?????

[fox]

After doing a search and a lot of reading, I may b e way off target by looking at the MAP. I need to also look at the IAT. I would bet that mine is way out of range. Will pick one up today, and may move it to the air horn. It should read better there and last longer.

Need to get to work, later guys.

 

[BarryG]

OK all. I tried Bobs ecm resetting method and a couple of interesting things happened. I unhooked the positive cable turned on the key ate dinner then rehooked the cables back up.



First and most important I lost my darn radio station presets



Second my wait to start light that had gone awol a couple weeks ago (it was still working after I installed the catcher one of the first things I checked at install since that was a telltale sign that the new ecm might be bad or the wrong one etc). My wait to start light seems to be working fine again now. Glad I didnt get fired up and pull the cluster to check for a bad bulb this past weekend now.



I drove up to the carwash and did not notice the surging however my drive to the carwash is very short and not a good place to check for it but I have noticed it in that stretch previously.



When I returned I checked for codes. 4 came up 1693, 0500, 0230 and 0601 or 0602. (After I hooked the cables back up I checked for codes then and there were none). I knew what the 0230 is and have had that before it has to do with my rasp pump, 0500 is no vehicle speed sensed which was there earlier in the day and has shown up intermitantly over the last few years. We all know the 1693 is a companion code and has no real meaning. However the 0601 or 0602 that showed up were ecm related codes. I pulled the codes then went to get my manual to look them up. I couldnt remember if it was 601 or 602 so I went to read the codes again. Now they were all gone. I suspected that the codes reset after 3 start cycles and assummed the codes went away becuase of the 3 key on sequence to get the codes (the 3 key on sequence equating to 3 start cycles).



So I figured I would check them again when I got to work this morning after my 20 mile commute. Low and behold no codes still. So I do not know what is up with the codes but at the present there are none.



Now on to my drive to work (which is almost all freeway except for 2 miles to get to it and 2 miles once I get off). There was a definite decrease in the surging. In fact I am not sure it did it at all. There were hints of it but nothing definitive. I will continue to check for it throughout the day and report back.



It does drive a bit different maybe it is because of the lack of surge and not having to try to find that sweetspot. I will continue to check for codes and the surge and keep you apprised of what I find over the next day or so.



If you are having this issue Bob's ecm resetting method definitely made a difference.



My truck did not do the surge before the catcher install at least that I could notice.



I am still as confused as ever about it but my wait to start light is back so at the very least it fixed that if not the whole problem. Time will tell on that.

 

[BarryG]

Well After driving around some today at work and getting home some new/additional info.



First-wait to start light is still working



Second -the codes 1693,0501,0230, 0602 that showed up last night now show up only if I check the codes with the 3 cycles if the shutting off the truck counts as the first one. If I shut off the truck and then go back and try and read them there are none. However if I shut off the truck and cycle two more times they come up pcm=1693 ecm =0501 not my previous stated 0500 and 0501 is not even listed in my manual so I dont know what the heck that one is, 0230 is my lift pump and know why it happens, and then the 0602 which says it is an ecm fueling calibration error.



Third - the surging is definitely less and when it does do it it is not as aggressive when it does do it but it does still do it just not as often or as hard as it was before.



Fourth-Now it also seems I lost some seat of the pants acceleration. Could be my imagination but I really dont think so. Though it may be that I was used to when it surged just really taking off and now it still does but more subtle than before.



Definitely confused at this point

 

[BRI7070]

Well I will try anything once,,,twice if I like it. I will give bobs method af resetting a try. I hope that this would reduce, if not elimiate the surge. I am waiting to hook up my TST comp box.

 

[KampinKid]

Bob, If you want to drive it again......

Bob and Marco, Just thought I'd jump in here and mention I'm dealin' with the same surge issue and I'll offer up the truck for a "see it for yourself" drive if you want. Unloaded it's most noticable going up Tiger Mt. but with the 5th wheel on the back you notice it anytime. I must admit that I've put over 9000 miles on the truck since the ECM change and I've just learned to be carefull with the pedal and now I'm really very happy with the way the truck drives(but I must go along with the others in this thread and say there are a few things that just don't seem right). Bob, if you want to sit behind the wheel and experiance this for yourself just let me know, I'm just down the road from you in MV. Ken

 

[fox]

An up-date. I found an out of spec IAT sensor. Changed it out, and WOW, the power is back.

The surge is mostly gone, I doubt my wife would even notice it . I do because I'm looking for it.

Map appears to be ok.

IAT read very high on the colder temp on up ward too.

Take it out, put it in cold water with a thermometer to test it.



So, I suspect the Surge issue is 1-2 sensors on the edge of their range of operation that the computer can accept. This narrows what the ECM can do.



BTW, switching between the Catcher and a catcher special, I see the same very small surge. No difference.

The difference I do hear is in the timing of the pump. Special is quieter at 60 mph. I want to keep the regular version!!!

 

[Bob Wagner]

Fox, Thank you for the update. Marco is very busy right now and he has your last PM.



I don't like to speak for marco. But he has thoughts on the sensor issue.

 

[BRI7070]

Fox,

What are the parameters that you used? I would like to try that test

Brian

 

[Walt-L]

Bob,

Hold off mailing me the new ECM, I want to try a new IAT first. Ill give Rodger a call for one at Hoesli Diesel this week. Hopefully, Fox is on to something here.

Thanks Fox

 

[fox]

Some else posted these numbers.

77____9k to 11k ohms

122___3k to 4k

167___1350 to 1500

212___600 to 675



My old one read 4. 1k at 80*

My new one was 8. x k at 80*

I will get more numbers from the old one tonign and compare to a new on.

Who can offer the factory specs over a wider range. ?

 

[BarryG]

Well with 160k on my original IAT I may just have to yank it and test it out. And see how it fares.



After having driven well over a thousand miles now since I did Bob's ecm reset I am still having the issue. It is not as bad as before at all but is definitely still there. It doesnt seem to do it quite as often or as noticeable but when it does do it it is harder to find that sweet spot. Before if I just backed off a bit that was good enough now I have to search for the spot. Backing off like before is now seemingly too much and have to reapply some go pedal and if too much back off a hair etc until you find the spot. My codes still come up 0501, 0602,,1693 and the other one which I cant recall 023? lift pump voltage(which I know why that is there). Still havent been able to find out what the 0501 means. Not listed in my manual or the couple of sites I found that list codes.

 

[Marco]

P501 = Vehicle speed sensor performance.



Marco

 

[fox]

Marco, for the time being, mine is running fine. Do you think it is the speed sensor? If so , why isn't the speedo acting up?

I said earlier, like last year, these trucks have a lot of electrical issues !!!

We must finish engineering them and then decide if we tell Dodge about the fixes??

Maybe they are watching.

 

[Walt-L]

Fox,

HAH, They like it this way!!! NEW Truck sales is where its at for them, Any cracker jack engineir could mil spec these out of the box. Its ALL about money,,, for the dealer service/parts and when your tired of that, its that NEW TRUCK smell that will make the problems go away... . for now. Its these forums and people like you and the rest of them here that puts "US" ahead of the game for a change!!!!

 

[Bob Wagner]

I agree fox is doing a great service here. Fox I appreciate yor input. It is my intention to supply the best product for our trucks and this helps with the surging issue which is fairly rare.



I have never had an issue .



Thank you

Bob

 

[fox]

This site is about helping others and I will do my part with a smile.

Thanks for the compliments, guys.



I have been looking for the IAT sensor plug - pair- to make an extention cord to move it to the air horn. Anyway, I was at Reilly's Auto parts and the emploee was real helpful. He called their tech support and will call me bak about it. BUT, he found that they actually sell the sensor, it was $16 and change!!!

 

[Marco]

Fox,

GREAT job. Thanks!



My thought's about the "Half throttle surge".

( I have finally some time to type... . )



First thing I had ruled out was the CaTCHER software. If it had a bug, then ALL the trucks would have that surge. As a lot of our friends who use my software know, that's not.



Wrong software version for the particular truck? I've checked everything and then checked again and then started again from the beginning. The fact is that I use so many " security and quality " controls, it's almost impossible that someone receives a different software from what's been ordered. Another possible cause ruled out.



Third possible cause could've been the ECM's as a Hardware. Also that's not. Bob has provided different ECM's to a few guys, the surge remained. Another possible cause... yep that's it... ruled out.



Yet, certain trucks develop the "Half throttle surge" when the CaTCHER is installed while they don't surge with a stock software. What gives?



At this point I'm lead to believe that what the CaTCHER does is it "amplifys" an problem that's already there due to it's much more aggressive fuelling and timing. I'm still scratching my head, the final verdict is still out... .



Any thought's?



Marco

P. S. On edit. I think it was in Y2K when I found out about the out of range IAT sensors. Since then I've relocated my IAT into the intake horn. No more dirt on it and it's still perfectly within specs.

 

[fox]

Good info. My advice to all members who have a surge issue as stated previously, try this.



Unplug each sensor, then re plug it. This will clean them. That will eliminate one possible cause. It will also teach you each sensors plug locking method. !!!

Then if it remains, replace the IAT sensor first. This does NOT guarantee the new one is in spec.

I am going to try to come up with some guidelines on where they fall as good or bad.



It is not the Catcher causing the surge, but out of range sensors.

Maybe I can find a cure.

 

[Marco]

A voice from the past....

That was written several years ago... .



During our development I've become aware of the fact that the Cummins ECM calculates the fuel the injection pump has to inject, based on the signal of two main inputs.



Pressure in the manifold AND the Intake Air Temperature.



Obviously the most important input is the pressure measured by the MAP (Manifold Absolute Pressure) sensor. To make it simple, the higher the pressure, then more fuel will be injected. This does not mean that the Intake Air Temperature sensor is less important!

To make it simple again, the higher the air temperature in the intake, the less fuel will be injected.



Hot air is less dense than cold air, thus less fuel has to be injected as the temperature rises.



What happens if the IAT sensor gives a wrong reading of the temperature?



In my case, the IAT sensor wasn't able to read very cold temperatures, but also didn't read high temps. It was like it's temperature range was much shorter than it should have been. When I compared my original sensor to a new one, I also noticed that it's reaction time was way to slow!



Before I proceed, I would like to point out that NO code has ever been set in the ECM/PCM!



The ECM can only detect a completely dead sensor. ( Voltage too high/low )



After finding out that my stock sensor was off of it's values, I proceeded to install the new one.



Installation is very simple. All you need is a 22mm socket and the ability to climb onto the engine since the IAT sensor is located in a very uncomfortable position. It's at the end of the cylinder head towards the firewall, on the driverside.



Here's a link to see where it is located:

http://dodgeram.org/tech/dsl/mt_2_feb98/fuel_sys_comp.htm





Once the new sensor was in, I noticed immediately that the EGT's at idle were about 75°F lower!!! Cruising at 85 the EGT's dropped about 100-120 degrees!!!



Great, and the mileage? Driving like I normally do, MPG is better by 1. 9 miles per gallon!



Yes, that's the number!



Sure, I can't claim that everyone with the "low mileage" has a bad IAT sensor, but I think it's worth it to give it a try. Obviously, I don't know how your mileage will increase, but from what I've seen through the WWW, several people seem to have the same problem like I did!



In my case, since the IAT sensor never gave an high enough reading of the temperature, the ECM was fooled into thinking that the air was cooler than it was in reality. Thus it added more

fuel than could be burned. This little more fuel added wasn't enough to increase performance, but was enough to KILL mileage.



Hope this helps.

Marco.

 

[BarryG]

Thanks Marco so my 0501 is the same as 0500 (at least in my manual it shows 0500 as the speed sensor). Well at least I know what it means.



I have recently replaced my map sensor. My old one was bad and causing some issues and giving me an intermitant map sensor voltage code. I did replace it a couple months before the catcher install.



So off I go to the IAT store. Your last post makes sense (I remember those posts about your IAT relocation) as I have lost some mileage over the summer. I usually get a bit less mileage (approx 10%) in the winter due to our winter fuel and this summer it never came back. That is until I installed the Catcher. I didnt get it all back but most of it. I have pulled the IAT to check its condition but it was clean as a whistle so I just put it back in and did not test it. If it is only 16. 00 I will buy a new one and test its values before putting it in.



FOX good job thanks for the info and the investigative work.