silverram323

I have noticed my engine has a little rev up after start. It has been doing it for a while and I figured it would go away but it didn't. It only does it once in a while, no rhyme or reason. Do any of you guys have or fixed this problem? All mods are in Sig
thanks kevin

dodgediesel4x4

What do you mean by rev? Are you talking about take off power, or rev as in rpms? I would replace the fuel filter, could be partially clogged, or not getting a good flow. Most problems do not go away, then tend to get worse. Sorry I couldn't help you any more. Good luck,

Hutner

Smokee

I am wondering whether you might have a very small air leak. That will sometimes make the engine give a flare-up such as I think that you are describing.

jrs_dodge_diesel

Mine does something similar. Mine will flare up right when it starts. Only happens when I stop for a few minutes, like going into a store. Its probably just a little extra diesel in the cylinders that wasn't burned at shutdown.

amartinson

Silverram,

Empty your PM boxes.

Andy

silverram323

A flare up is what the word is right after i start the truck. I pressure checked the intake but was ok, I still get 34# boost.

bluebull

silverram323,

I know this post is going to be long but want to get all possibilities out. Maybe you can relate to some and find your problems.

Mine does the exact same thing as yours, intermittent and at any time, just sporatice here and there and only on start up. RPM flare will go up to about 1800 RPM for a milasecond.

The only thing I see that you and I both have is the comp box, I am not saying the comp box is the culprit, in fact if you read my whole post you will find out it is posably related but fixable.

My truck started doing this the fall of 2002. At first I thought it was just a loose wire or corrosion so I disconnected every connector (ECM, PCM, APPS, MAP, IAT, Comp box, anything that had a connector) and dielectric greased them all. The truck still done it. Disconnected batteries for a day, hooked them backup and reset APPS, it still done it.

I then suspected the comp box, after all it is corrupting information between the injection pump and ECM. I called Edge and they sent me a new box at no charge, great customer service since I had the box on for about a year and was out of their warranty. I unhooked the batteries for 4 hours and then reset everything. the truck still done it. I then suspected the cruise control because it seemed like the only time it would do it was wet weather or when I had been using the cruise control. I unhooked the batteries for 4 hours and reset everything, then drove without using the cruise control and it did seem to help but the flare up at start up still persisted just not as often. I even disconnected the cruise control cable for a while but it still done the flare up. If I remember correctly yours does not run by cable but by wire through the ECM, PCM, and APPS.

For christmas my wife bought me a superchip 3705 programmer. I checked my codes using the programmer and they came up,
P1689- No communication between the ECM and injection pump module.
P0602- ECM fueling calibration error.
I then thought darn, injection pump or APPS going bad!!

I thought about the codes for awhile and what implication they could have. I just could not understand how the injection pump or APPS could be going bad for a year and half and approximatly 20,000 miles without completely failing so I started thinking about other problems the codes could be caused by. The only thing I could come up with again was a loose wire or corrosion or a connection between the comp box, these are the only communications points between the ECM, APPS, and injection pump.

After thinking for several days about the communication thing between ECM and injection pump the only thing I could come up with was the scotch lock on the pump wire or the wireing from the comp box. I disconnected both batteries again. I took the air horn and APPS assembly off. I took the scotch lock off, stripped the coating on the pump wire and soldiered the comp wire directly to the pump wire. I used plastic dip and or liquid tape to seal bare wires. I then cut the comp wire further up and added a protected male connector to one side and a protected female connector to the other side of the comp wire. I did this so I could leave the comp tap wire disconnect but be able to hook it back up later after I get done experimenting, also so I have good connection later and be able to disconnect the pump wire if I ever need to take my truck some where for service. I never let anyone work on my truck and highly doubt I ever will but just in case. I also disconnected the comp from the data port. I reinstalled the connector protector on the data port that came originally from the factory and then cut the fingers out of disposable latex gloves to put over the exposed ends of the data port and comp wires to keep dirt and moisture out. I left the MAP sensor harness plugged in so I could still have a boost fooler. I need it for towing with the other modifications in my signature to keep EGT's down.

Well, after driving like this for about a month and useing cruise control the truck has not over reved at startup. I am going to drive like this for a while longer just to be sure but it looks like it is either in the comp wiring or that nasty scotch lock. My educated guess would be the scotch lock. I plan on hooking things back up one at a time and test driving just to be sure. The data port first and then later the pump wire. If everything is o.k. at that point I will know for sure it was the scotch lock connection, if it does it again then I will know it's the comp box wiring as I have already eliminated the comp box, factory wiring, cruise control, ECM, PCM, APPS from the equation. The next step would be the comp wiring. I just know it is the scotch lock but will eliminate the other posibilties first.

Please excuse my spelling, I could not find spell check.

Hope this helps.
bluebull

silverram323

Bluebull,
Thanks for the info, I just put the comp box on 4-09-2004. I had a edge ez before, so maybe its a edge thing. Ever since the truck was new i had a box on it.
So you soldered the pump wire and yours don't seem to do it anymore? Hmm I have a blue chip pump cover so mine is different. I will have to grease all the connections again. Thanks

Sootman

I have the same problem with my truck. My truck does it when it is really cold out. Right after it did it the check engine light came on. Code 1689 came up. I did the same thing you did with all the connectors and coated them all with dielectric grease. No help. It has done it to me about 6 times when its really cold out but in the warmer weather hasn't done it. I also have the blue chip cover so maybe it has something to do with the edge comp box. I was going to send it back also but I'm going to upgrade to Drag Comp so when I send it back I'll tell them to take a look at it. If you do ever pinpoint the problem please let us know!!!!

bluebull

Update,

After driving around for a few months and a few thousand miles without any RPM flare up since I disconnected the data link port connector I decided it was time to hook it back up.

Guess what, after about five startups the RPM flare came back. I think it is either the data link port connector or a faulty wire for the data link on the comp side.

I called Edge products today and I didn't hear what I wanted to from them, but I will send the wire harness back to Edge so they can check it out and then I will go from there. I hope I didn't purchase a $600.00 boost fooler.

bluebull

Hats off to Edge products, once again they have proven they are superior in customer relations.

Edge products replaced every thing new, wire harness, comp box, boost elbow, clamp, even the velcro and wire ties. Will install and see if my problem goes away.

Thanks again Edge Products.