Started Friday sitting in stop and go traffic after 20 miles of highway driving. Light acceleration (8-15% tps) and it developed a terrible surge. Can see the rail pressure is down 5k from where it is usually.It feels like i am on and off the pedal. Truck feels like it lost a couple hundred HP as i am pushing the pedal past 50% and it barely goes. Does this for about 5 miles to home. Shut it off and let it sit for a 15 minutes before i go back out. Truck runs fine. Saturday after it was running for a good hour it does it again. Surges bad to the point that my wife asks "What's wrong" Down on power again. Feels week all day during my 100 mile trek.
Sunday, same thing. Runs good for 20+ miles then suddenly surge and loss of power.
Tonight i get the scanner hooked up. when truck runs good under normal acceleration in the 20% tps range it throws you back and spools great. 20%tps the rail is in the low 20k range for rail pressure. Next stop light i am at 45% tps and the rail is struggling for 17k. then back to normal. It was as bad as 68% tps and the rail never got over 18k. Does this the whole time i am out on a 20 mile loop with the wife watching the scanner. one minute it's good. next it is bad. I have talked to Todd at T&C as i originally thought it might be a bad FCA but he does not think so. He did say there is another guy with a similar issue who has replaced Cp3 parts and still has the same issue. No codes other than the usual for a conversion truck. It has run flawlessly for 5 years and 45k. I feel like i am looking at it but not seeing it. Any help would be appreciated.
Sounds like fuel starvation so My first guess was fuel filter! But if thats not it and delivery is always at about 13 then the next guess will be either CP3 or the injectors are about to take a dump.
I had a long talk with Todd @T&C Wednesday. Great guy. Spent more time than i expected going over things. Only thing i remembered durring the conversation that i forgot was RAIN? When i had the worst surging it happend when it was wet out or shortly after. We came to the conclusion i have a connection issue or a damaged harness. When the truck shakes it gets an intermittant ground/open in the harness?? I am going to start snooping around for a rub mark or an obvious tear in the loom. Todd also suggested i Dielectric grease all of the connections. On wednesday i pulled the rail sensor plug and the FCA and did them. I also checked those for the rubber seal and they were both intact. It has not done it since. I am going to wait and see if it happens dry over the next week since we are not expecting rain here till Thursday.
So the truck runs fine on a cold motor?
Does it ever hiccup at idle? man, it could be a lot of things
might i suggest low pressure from a water hose around certain parts of the harness at a time and see if you can duplicate the problem?
i would you could data log it. you could see so much more at once
Truck has run flawless since i greased the 2 connectors. I was planning to water the motor today and see what happens. I'm thinking i had a bad connection on one of the 2 connectors and the engine vibration or water intrusion was causing the intermittent good/bad scenario.
If only i had a data log.
Well its been a month and it has not acted up again. Even had flooding conditions yesterday and ran my truck through some 2+ foot deep water and no hiccups. At this point i am going to chalk it up to a bad connection at one of the 2 fixed by jut simply cleaning and Dielectric greasing the plug. I again want to thanks Todd @ T&C for his time even though i have not been a customer. I will be his customer in the future.
Dam thing did it again friday night.
One thing i did notice was the pedal was dead when it happened. I had no TPS reading on the scan guage when it happened a couple of times. Other times I could see the TPS drop then climb if i held a steady pedal . Rail pressure followed the TPS drop. It seems to happen below 30% TPS only.
No codes? Bad TPS would throw a code. So again your at the harness. I would think that when you took off the two connectors you moved the harness enough to temporarily make the bad wire or connection good for a while. Then over time it went back to where it was originally for the past 100k and problem returns! Did you try the wiggle test? Have someone sit in the cab and give it 10% tps on the scan gauge then start wiggling and have the helper yell when it drops to 0. If it doesn't do it then it's in the connector itself.
Find the TPS wire and do a resistance and or voltage check on the pin. Wiggle the wire with the Multi meter hooked up and see if you can duplicate the issue. Electrical issues take a lot of time and are very frustrating> Its worth it to take it in to the dealer if they are worth a damn or a good shop and have them rip their hair out! You sit home have a beer wait for the phone call!
dangerous06
I tried the wiggle test with no results. The plug on the TPS looks solid and there is a wire support 2" from it so the wire has very little flex.
RDPsmoker
I can watch the TPS on the scan guage and it goes from 0-100% there. Have not had a chance to get the scanner on it.
MAXTORQ
Harness is the original that came with the motor. Tag on the motor said
03-03-03 build date. The APPS is the one that was on the motor when i got it. I ran out of time this past week to get the scanner on it. I will get some reading and see if there are code's
I have been on the fence about a harness swap so i can go to EFI. I might just go that route and eliminate the search for this intermittent issue.
Has anyone used a Painless harness? I wonder if it vs a NEW from Dodge hraness might be the way to go. I have a source for a USED/ Salvage harness but now am wondering if new vs old is worth it.
Finally had a chance to throw the scanner on it.
P2121 and P2122 for the APPS sensor.
At this point I am going to throw in the towel on the 03 ECM.
I just talked to my buddy and he is rounding up a harness and ECM for an 06
EFI Live here I come in the spring. :woohoo:
