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01 Idles fine but misses/defuels at 1600 rpm and above HELP!!


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I need help here. I have a 2001 with the 6 speed. The clutch went out a couple weeks ago so I decided to do some long overdue work on the truck while tackling the clutch job. I put a new south bend dd in and a new slave cylinder assembly. I also changed the drivers fender as well and pressure washed the entire engine and undercarriage. The truck ran perfect when I shut it off to do all the work. I have the air dog 2 with a 2 year old industrial injection vp44. I've always had 20 psi fuel pressure at idle with about 17 at WOT. When I got everything back together and started the truck, it idles perfect but it won't rev above 2000 rpm and started defueling causing a missing and backfire around 1600-1800. It pours black/blue smoke like it's tuned but it has no programmer. I also had a horrible sudden fuel leak from the connector tubes so I changed all the orings and fixed that problem but still there was no change to the engine sputter and defueling. I ran the codes and had these codes P0234 p0113 p1698 p0251 p1287 p0252. I can't help but think I'm missing a ground somewhere or have something wrong or wet but can't figure it out. I have a hard time believing that the IP just quit at the same time I did all of this work. Any help would be appreciated. 

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I would start by pulling apart any of the large connection blocks, blowing them out and reconnecting them. The ones I know of are the main pin connection blocks on the VP, The ECM, the computer or PCM. There is also one up high near the firewall just to the driver side of the valve cover. It has a white bail that clips in place to keep it tightly connected..That one has caused similar symptoms your having. Be careful that you line up the connector blocks before trying to force them back together. Just do it so you don't damage or bend any of the pins.

 

Next I would be thinking about changing the factory fuel filter and getting a look down in the bowl for water. That plastic screw cap has to be torqued the right amount or it leaks air. Also use a socket on it, not the square inset for a ratchet. It's been known to  cause a crack in the plastic.

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Ok, I blew out all the electrical plugs with air to make sure they were dry. I also replaced the main ground wire on the drivers side battery. I still have the same problem. 1600 or so it starts popping like a rev limiter up to 2100 and blows some black smoke. I can hear the turbo spooling up but where should I go next?

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Posted (edited)

Ok I just had the codes ran again. Let me say 1st that I have no way to clear codes at the moment but prior to me pressure washing the entire engine bay, changing the clutch, and changing the fender, I had no check engine light or codes other than the 1698 for a bad ground on passenger side battery. The truck ran flawless and I've never had a problem with it.  The glow plugs I unhooked and left off the truck when I changed the fender. I'll post a pic of the codes now and tell me where to go next please. 

P0237

P0234

P0113

P1698

P0251

P1287

P0380

P0382

P0236

P0252

 

 

https://photos.app.goo.gl/DhcQ9c4xJYznQJ82A

Edited by Jasonsneedinhelp
Forgot something
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When you pressure washed the engine bay, did you happen to pressure wash the wiring connector to the ECM? On driver's side engine block below, in front of fuel filter ?  Is there a chance that got damaged-water forced in where it doesn't belong etc?

 

 

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These trucks are so electrically challenged that I wouldn't introduce a thimble full of water anywhere inbetween both bumpers, I even drive around puddles 😀

Edited by wil440
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Ok so I got the codes cleared and the only 2 that come back now are p0251 and p0252. I'm beginning to fear the worst has happened. On a side note though, yes the ecm plug could have been sprayed directly. I know the ecm itself was but the truck had no batteries in it at the time and didn't have for about 5 days after.. idk guys, is there anything left that could cause this other than the pump? I have not cleaned the ground for the ecm but could that even cause these codes??

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Posted (edited)

Ok guys, I got it fixed. You'll never believe this crap. While I had the drivelines out, I think I forgot to mention that I dropped the fuel tank and repaired the fuel gauge sender. When I got it all back together and started it, my fuel gauge was pegged at 30 psi at idle. I adjusted my air dog back down to 18 at idle and until today I never could figure out what happened. Apparently when I put the fuel tank back in the dark, I pinched the return line between the tank and frame.. I found it today and fixed it and when I started the truck, my fuel psi was 10. I adjusted it back up and it's running great. My final question is, how much damage do you think I did running it like that for nearly 100 miles trying to figure the stuff out? It seems to smoke a little more than it ever has now but I've also always had fuel leaks that I no longer have. It's black smoke. Not white or anything. I am dropping 6-8 psi now tho at WOT. I am dropping from 18 down to 10. Should I bump it up a little more to say 20 at idle to keep 12 or so at WOT?

Edited by Jasonsneedinhelp
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If you did any damage it should be minimal. How much damage is any ones guess.

 

What suze fuel lines do have from the the tank to the VP? 8 psi drop is quite large. I run the same as you on .5 inch lines with only a 4 psi drop. I keep my pressure above 14 psi at all times. 

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I believe they are 1" lines. They are blue. I'll measure them tomorrow. They could be 1/2 I guess. My return is on the factory line from about a foot below the "T" at back of the motor above the starter until it reaches the top of the tank then it goes back to the blue bigger hose. I've always only dropped 3 psi before but now I am dropping 6 at WOT. I can make it drop 3 psi in neutral revving it to 2500.  I'm a little worried that it may be damaged. It also pops with a miss if I WOT it while in neutral. Right after I hit the throttle it'll pop then revv up fine with a puff of smoke. 

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