Engine/Transmission (1994 - 1998) 94 12v ppump Fuel heater problems. Help!

[Dodge1994'12v3500]

Hello there, I've got a 94' 12v cummins wit a p-pump. Ive been having multiple issues with it. Its been idling rough so I adjusted timing to 16° and when warms feels much better, but while cold idles awfully rough and dies without throttle, and also has alot of blue smoke but only when cold. I though maybe fuel heater air leak so went to trash it. Unplugged it and diesel came out where it plugs in! I tried to remove it and the hex nut but it's stripped round. I have tried everything, vice grips and can't get that succer off. Any suggestions? :-laf

 

[GAmes]

Is it the fuel filter bowl that is stripped or the allen head bolt that holds the heater in place that is stripped? Either way, more than likely you will need to remove the lift pump as an assembly. With it on a work bench disassembly should be easier. You need to adjust your idle.

 

[The patriot]

If it was me, unless it's relatively new, I'd replace the lift pump while it was out.
Also, install the studs. Your life will be much easier if you do.


Edit, may as well check the overflow valve for propper pressure. It's a common thing.
Get a torq tek valve. Theyre about $45

 

[Dodge1994'12v3500]

Thanks I just ordered a tork tek valve last night that's funny you mention it
What are the studs? Sorry for being a newbie, the lift pump is new and I have a spare when it goes.

 

[Dodge1994'12v3500]

Okay, it's the nut on the bottom of the bowl. And my idle sits at about 850 when it's warmed up, it's only low when it's cold

 

[GAmes]

Okay, it's the nut on the bottom of the bowl. And my idle sits at about 850 when it's warmed up, it's only low when it's cold

Idle with a manual transmission should be checked at operating temp, A/C on. Automatics in gear with the A/C on. If you have 850 with those requirements it shouldn't die at idle even when super cold.

The studs are used to replace the mounting bolts. Hang a gasket, hang the bracket, hang another gasket, hang the pump, install nuts. Much easier than doing it with the stock bolts.

I average more than 300k miles on lift pumps. You'll be carrying that spare for a long time.

Rather than throwing parts at it (OFV) I suggest you find out what your fuel pressure is first.

 

[DonFitzwater]

If it was me, unless it's relatively new, I'd replace the lift pump while it was out.
Also, install the studs. Your life will be much easier if you do.


Edit, may as well check the overflow valve for propper pressure. It's a common thing.
Get a torq tek valve. Theyre about $45

Install the studs instead of the bolts that mount the pump/heater assembly to the block! It will save you from pulling your hair out when reinstalling on engine. Makes life much easier.

 

[Dodge1994'12v3500]

I am low on $$$ and was wondering what fuel pressure guage to put on it. I'd like to get the cheaper one that goes on top of the filter housing. Larry bs makes one, does anybody recommend or do they suck?

 

[DonFitzwater]

Why even bother on a 12 valve? I've never had fuel pressure gauges on any of my trucks except the VP44 equipped 24 valves. Just my .02

 

[BigPapa]

Can you get a strap wrench on the bowl or maybe even a large pair of channel locks?

How many miles on your truck? My fuel pump has @ 400K miles on it and still going strong but if you're going to remove it I'd definitely do the studs. I wouldn't mess with a permanent pressure gauge either. As to the OFV, I did the spring mod to my stocker and it's fine. If I had to replace it I'd stick with the stock one instead of the TT.

 

[Bob4x4]

You can use a factory vp44 fitting that came with a pressure port in it or one that is available at many aftermarket diesel shops.Alway make sure your low side pressure i with-in spec before making any pump adjustments.As far as timing goes more is not always better.1-2 degrees more than factory on a stock truck.

 

[GAmes]

I have a fuel pressure gauge, and do not feel it is unneeded. It is the best way to troubleshoot the system AND it will pay for itself by decreasing the number of fuel filters you buy. I only replace my filter when the pressure starts dropping. Works for me. There isn't any need to spend a lot for one either. I went with the Isspro EV2, but I bought two senders and can also monitor my oil pressure via a toggle switch. Here is the inexpensive way. http://www.cumminsforum.com/forum/94-98-engine/137589-how-check-fuel-pressure-12-valve.html

 

[The patriot]

My LP went around 65K. IIRC
Power was down, First did the filters....ng...did the heater eliminate thing. Still down. with low pressure. Changed LP, all was good. (low-mid 20 psi range) Did the torq tek OF valve 31 psi all the time with new filters.
So, my LP didnt outright fail, it just was weak.
As a side note, I got one of those long discontinued genuine Cummins LP rebuild kits. I'm rebuilding my original pump.

 

[Missouri Mule]

My lp went around 275000 and 300000 overflow went 4 weeks later.
Fh connector I don t think it leak fuel when disconnected.
But i never have disconnect it. I have many years ago took the bottom off it and cleaned the screen.*
How cold is it when fire it up? *When it warms up are you driving it down the road?
Running rough because of air leak at heater connector. But could be that there is large piece of large dirt in fuel filter. *I have to filter a few times because of this. Usually it caused trouble when i fire up Mule it act like the engine was going to die, a push on the go pedal kept it running after that it was fine. Changed filter ( when found some free time.) I had turn filter toward its side then turn it up right to get all the fuel out of it. A couple of months ago after I headed down the road and ****ed to third it felt like the engine was going to die. After I got to the first stop sign it fine then. Changed fuel filter ( piece of large dirt in it) *no problems since then. I also quit fueling up at place i usually do. *So far no problems.