12V Fuel Problem
 

I've got a 94 12v and I have been getting a lopeing idle lately, sometimes this leads to a clacking under the hood, and loss of power, but most of the time just lopeing! anyone know of this problem? Just replaced leaky return line off IP, and fuel fillter... Thanks

HI patclark, You will get more respond, if you post it in the CUMMINS section !!:ok1:

/me moved to 911 section , Have you cleaned the bowl and Screen

pre heater bowl and screen? if so then nope haven't gotten there yet

Could also be timing. Have you ever re-timed or checked the injector pump?

never timed or checked it, don't know much about it, what is there to check? not a bad place to look! thanks

You need special tools to do it. Timing tends to slip from the factory because they didnt torque the nut on the pump shaft correctly. Heres the procedure:

TSB 18-10-94 Rev. A

Have you noticed any kind of white smoke or any other issues? This problem could also be the overflow valve.

What is your idle set at? Should be minimum 750 rpm - 800 is even better.



Heres more info on fuel pressure:

http://dodgeram.info/tsb/1996/14-07-96.htm

some white smoke at higher RPMs, but seems to clear after a few seconds. feel as though the idle is a bit lower than 700, just now able to get my hands on a diesel timing light, so I will be checking it. Kinda thought about the overflow valve, I did notice that you can see the return line pulsing and hear it when your under the truck. Just replaced the soft hose on the return line, big leak in that one

The fuel supply and return hoses are a big problem. If they arent replaced, the dry rot and let air in causing the fuel system to lose prime.

You arent needing a diesel timing light - you are only concerned with the timing of the injector pump - as I said, you need some special tools:

SP500, Set, Diesel Timing Gauge

A barring tool to turn the engine over would also be handy.

Think I can get my hands on one of them too. Guess I should replace the supply line as well? Have you ever head of the braided ones to the tank going bad?

I would start by replacing all the fuel lines, 2 at the front 2 at the tank. Supply lines are 3/8" and returns are 5/16" - you need about 4 feet of each. And do not use regular fuel line - get yourself some diesel rated fuel line or you will be doing this again in a short period of time. I can tell you where to order it if you cannot find it.

Im not sure how long your had this truck, but it may be some time for some preventive maintenance.

Thanks, had it for about two years, and been doing all the other stuff, just now learning about this kind of stuff! and I can get my hands on the better fuel line where I work, so it shant be a problem. Thanks for all the help, I'll be back soon with an update as to how it's going:argh:

Make sure you come back and we will see if we can get it figured out for you.

Ive got to ask - you know about the KDP (Killer Dowel Pin) thing right?

so DR. I have now replaced the overflow valve, and it seems to have more power and have not gotten it to start clacking, need to drive somemore though, but I did get a loping idle, only for a few min.... replaced the heater to lift pump hose, return line hose, overflow valve, cleaned the heater screen, and replaced the WIF sensor, do you think the lope could be air in system? also hooked up a fuel pressure gauge, since replacing the over flow valve it has better pressure but still jumps all over from 20-25 at idle to 26-30 under no load, and 28-35 under load? one other question when I hit the prime pump with everything closed I can hear a squeak like something is coming out a tight hole, is this normal?

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oh ya, and I don't know about the killer pin dowel?

Is it cold where you are by chance?


The reason I ask is, if I got out on a cold morning to start mine it lopes for a couple minutes. But when it's warm it doesn't do it.

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good reading on the KDP.... ~here~

cold yes, and I will get that sometimes when I don't plug her in, but this problem seems to happen after warming, and driving for a bit, or driving, shutting down, then starting again???:argh:

how goes it :pca1:

Well I installed a new pressure relief valve, and my fuel pressure was really good, and then drove to work last night and drove hard to see if it would act up , and when I was just about there the throttle stuck wide open, shut it down restarted and did the same thing, and then quit doing it. After work started up the truck, ran like crap, bled the air out of it, but there wasn't any just acting like it, started it up, throttle stuck open for 3 starts, had a buddy looking at it with me, then it wouldn't restart? Think it's the injection pump, i guess the loping idle can be from the plungers going out? hatin life right now

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oh ya...:argh::argh::argh::argh::argh:

Any luck yet??

Well, the worst has happened, it was the injection pump, or at least 99.9 percent sure, pulling it out this weekend and having it checked, but my poor old girl is dead as of current. Any suggestions as to getting a cheap one?:argh:

Sorry Pat - I will try to get to the questions you asked sometimme today - I was away working and ended up hurting my hand - so Im having a hard time typing.

How many miles do you have? Fairly rare for it to be the IP, but not unheard oif. The P-7100 is known as the "Million Mile Pump"


BTW, did you catch the bit about the KDP posted by Cummins97 ??????

Any luck??

Any updates??

Patclark, am closing this down for now.