Can't get my truck to fuel hard

turboman1

turboman1

New member
Joined
Aug 20, 2008
Messages
248
About 2 weeks ago I went to the strip and ran an 18.2 with an number 11 plate full forward and the AFC modded some (washers flipped, smoke screw, and the spring in it had full travel at about 20psi)... So I then took the afc out and the plate and it ran a 16.83 at about 80mph with out a hint of smoke except when I was staging.
So this past weekend I installed a new lift pump along with the 4601HP Carter electric fuel pump. I also installed a #6 plate and less stiff spring in the afc...both full forward.Took it to the track yesterday for the nhrda event and only ran a 16.5!

Does anybody have any ideas as to why this thing is not fueling. We think the overflow valve could not be working causing diesel to just run through the pump.(Side note= bought an oil pressure guage from harbor and freight for 16$ and used as fuel pressure and it would go back and forth from 0-40 psi at idle in tune with the engine rpm and did so through out the whole rpm).

Could it possible be the injectors?

I appreciate all the help I can get and hopefully we can get this problem fixed.

Adam
 
turboman1 said:
About 2 weeks ago I went to the strip and ran an 18.2 with an number 11 plate full forward and the AFC modded some (washers flipped, smoke screw, and the spring in it had full travel at about 20psi)... So I then took the afc out and the plate and it ran a 16.83 at about 80mph with out a hint of smoke except when I was staging.
So this past weekend I installed a new lift pump along with the 4601HP Carter electric fuel pump. I also installed a #6 plate and less stiff spring in the afc...both full forward.Took it to the track yesterday for the nhrda event and only ran a 16.5!

Does anybody have any ideas as to why this thing is not fueling. We think the overflow valve could not be working causing diesel to just run through the pump.(Side note= bought an oil pressure guage from harbor and freight for 16$ and used as fuel pressure and it would go back and forth from 0-40 psi at idle in tune with the engine rpm and did so through out the whole rpm).

Could it possible be the injectors?

I appreciate all the help I can get and hopefully we can get this problem fixed.

Adam
Click to expand...


Did youu install a needle valve with the guage? If not, that is whats making if fluctuate. It will beat the guage until it breaks.

Also, Check you fuel shutoff solenoid to make sure it is set to full open. The solenoid is basically the valve that lets fuel into the pump. If its not adjusted properly, then it will not let full flow into the pump.

I also posted a link for overflow valves. Its a cheap part to replace. The spring on the inside gets weak and causes the fuel pressure to drop.


Diesel Hard Start Diagnosis


Ram Diesel Injector Pump Problems

Overflow valve. Same part#s as Cummins, but $40 cheaper.
BOSCH Dodge Cummins P7100 Overflow Return Valve NEW:eBay Motors (item 260429925048 end time Jul-16-09 07:49:45 PDT)
 
Last edited:
We checked the fuel shutoff soleniod and it is all the way up. I have work this week in a different town and won't be home until friday so ill have to wait on checking the overflow valve. Ill post what happens when I get that checked.

Could it possible something in the injectors?

Thanks
Adam
 
I dont think you would have an injector problem.

How did you check the shutoff solenoid? Did you take the solenoid off and make sure that it is pulling the arm all the way up, or did you just look to make sure it was in the up position. You need to take it off and make sure you are getting all the travel you can out of it.

Also, get someone to hold the fuel pedal all the way to the floor while you check under the hood to make sure it is getting full throttle. If you can still take your hand and move the throttle lever a little farther then you need to adjust it to give full throttle with the pedal.

Did you take the AFC foot out completely when you ran it with no plate? If you didnt take the foot out all the way, then I would do that before i did anything. You could have a boost leak in the AFC line or in the AFC itself which would keep it from moving the arm out of the way.

I ran a 16.2 with my truck with nothing but a plate, and GSK. I had a stock transmission with a transgo shift kit and lockup switch.

Does it smoke much before you get on the boost if you mash on it, or is it really light?

What was your 1/4 MPH, 60ft, and 1/8 mile times? These can help determine if it really is a power problem or if its a driving/launching problem. Also, what are EGT and boost at the end of the 1/4.

Eric
 
Eric,

For the fuel shut off soleniod I started the truck and pulled up on the bottom of it with my hand and it would not go any farther so I figured it was all the way up but you think I should take it off to make sure it is. i also pulled it all the way up without the truck on to see if it was catching on anything and it went to the same position when the truck was running.

I did not remove the foot just the spring in the afc but I would still think that with just the movement of the govenor arm that it would push the foot forward? I guess this weekend Ill try removing the foot and see what happens though.

The transmission is a fully billet trans by goerend's and I do have a lock up switch.

As for the times they are all back at the house and I won't be back until thursday night. I do remember the 60' were all 2.230 around there which was at about 15lbs launching.

Egts never even hit 1000*F maybe 900-925 and the smoke of idle is next to nothing and it might put out a small hazzi puff when I lock the convertor up in 2nd and the rpms fall to about 1750 because it only revs to about 2300 and then shifts because it stops pulling. In the high rpms starts to pop a little because of not enough fuel and it does that at about 2500 on up.

Here is an example: During the 1st elimination round the other guy dialed an 18 something and i dialed a 17.45. He left a little over a second before me but just a short distance after the 60" mark i was already nose to nose with him and then by the end my front tire was at his front bumper.

Hope some of this info is useful
Adam
 
Well, on the shutoff solenoid. The rod that goes up in the solenoid bottoms out in there, so it doesent mean that its pulling the lever all the way up if it wont push any farther, it could just be that it was bottomed out in there. But, normally they are adjusted right, so i would leave that alone for now. But, if you want to eliminate that problem, take the shutoff solenoid off(2 bolts, a clip, and a connector), and wire the arm up as far as it will go.

It sounds very much to me like you either have a hole in your AFC line, or your AFC is not working correctly. It sounds like the AFC foot is not moving out of the way. The governor arm wont push it out of the way. It is the boost pressure coming into the back of the housing that does it.

If I were you, I would take the AFC arm completely out. Its not hard to do, and it will eliminate that part of the equation. I would also either take the plate out, or put a #0 plate in it to eliminate any problems there.

Then once you do that, take it for a ride. I bet you have a lot more smoke and power then because i think that is where your problems are coming from.

Your 60ft isnt the best, but i think its because you arent getting much fuel out of it. That and your times should improve a lot once you get it figured out.

Give that a try and let us know how you make out.

Here is my truck running a 15.02. Stock turbo, 215 injectors, and 181 delivery valves. It didnt smoke any once it was spooled up, but it would blow quite a bit if i lugged it or when i was spooling it up.

YouTube - Drag racing at TS

Eric
 
I hope it is as simple as the AFC leaking I won't be able to let you know until thursday when I get back from work.

When I took the spring out of the AFC housing the lever/foot would just flop around so I did not think it would make a difference but I will try and take it out. You think that it was unable to move the foot even with no spring?

Just a quick description of how to take the foot out would be helpful before I get into it again.

Thanks for the help
Adam
 
Well, taking the spring out should give it full travel, but i would just take it out to be sure. There is a bolt in the front of the housing(on the outside) you take out, and then slide a rod out of it and it will come right out. Its worth a try.

Eric
 
Alright thanks Eric I will give it a try later this week and let you know what happens.

Adam
 
Well I pulled the foot out of hte afc and removed the plate = no more power or smoke at all.

I guess next i am going to check the overflow valve and the fuel shutoff solenoid.

We installed the 3 gsk over a year ago and i really did not see a difference in it so the problem goes back before I started to mod the truck more

Anbody think the rack could be getting stuck and any more throttle input just compresses the spring between the end of hte rack and the rocker arm assembly?

Any other ideas would be greatly appreciated

Thanks
Adam
 
That is wierd. Maybe someone else has some ideas.

I would definately take the solenoid off and wire it up as far as it would go and see how it does from there.

Eric
 
Thanks man this is going on the fourth week trying to get it fixed and no go so far.

Anybody else have any ideas? I know the stock injectors are onyl good to about 350 bhp but my track times are no where close to that hp level ~ 232 i think with my times i ran.

Thanks
Adam
 
Hard to say, i seem to be in the same boat also...

When i first started playing with my truck it had ALOT more power and could smoke out the better part of a 4lane road. Now its got a hard time to puff a little haze out and runs much slower.

My FP is also good, solenoid pulling 100%, seems to be running about the same overall with the exception of a very weird intermittent 'miss' under light/medium acceleration

havent checked to see if the pedal is actually hitting WOT... maybe the cable stretched...?

Other than that im thinking maybe injectors.... they might not have liked all that WMO ive been running through it!
 
Well I am running straight #2 and not WVO, but i am pretty sure WVO would lubricate the injectors better than #2. Thats strange it started doing it all of the sudden.

My fuel pressure guage is broken so I have to get a new one to make sure the pump is getting enough fuel.

Right now I guess I should just keep testing stuff and try and find the culprite.

As there anyway that the pump could just be worn out around the plungers causing the diesel to leak by them? I would think I would find diesel in the oil then right?

I have checked and made sure it is hitting wot when the pedal is on the floor.

Anymore ideas of what I should check.

Thanks
Adam
 
Have you actually checked to see if you get full rack travel? If you pull the AFC housing and plate out of the top of the pump you should be able to look in there and see if the rack is moving freely or not.

The other thing I would consider looking at is your governor springs. Make sure that you have enough spring tension on them to work right. Weston has a good reference here for how much spring tension to put on them: GSK Clarification - Competition Diesel.Com - Bringing The BEST Together
 
turboman1 said:
Well I am running straight #2 and not WVO, but i am pretty sure WVO would lubricate the injectors better than #2. Thats strange it started doing it all of the sudden.

My fuel pressure guage is broken so I have to get a new one to make sure the pump is getting enough fuel.

Right now I guess I should just keep testing stuff and try and find the culprite.

As there anyway that the pump could just be worn out around the plungers causing the diesel to leak by them? I would think I would find diesel in the oil then right?

I have checked and made sure it is hitting wot when the pedal is on the floor.

Anymore ideas of what I should check.

Thanks
Adam
Click to expand...

WMO not WVO ;)
 
Well Today I checked...

1. Fuel Shutoff soleniod = pulling all the way up

2. I did the Smokem govenor spring mod with the the sotck idler spring and the biggest 3gsk spring

3. Placed a ball point spring in the overflow valve. I cut it so it coil binds pretty close the same time the other one does.

4. Looked down from the top of the pump and could actuall feel the rack stopping on the mack plug. I know it had to be close there because it wasn't very far from the fuel shut off lever inside the pump.

What does all of this equal = Can't really tell right now as the transmission is acting up.

The trans is shifting really lightly and today when I drove it... it would shift into 4th and right back into thrid and stay there. I called goerend and he wants me to put a guage on it to watch line pressure and then we will go from there.

I am starting to think that the injectors can't just flow anymore fuel and that is my problem. I do not think it is the DV's because i thought the 181's have been dynoed up to 700 hp.

Anybody know of something else I can check?

Thanks
Adam
 
Weston said the GSK mod actually causes hard starts after awhile. When I PMd him about it, he told me to leave my 4ks alone. He said he was working on something else.

Yes, you could be at the the injectors max. I know 215s are good to just under 500hp. What do you have in there now? 180s?

181dvs have been dynoed to 700+.
 
Yes it has the 180 injectors in it...what kind of horsepower levels are they good for?

So I should put the 4gsk kit back in?

Thanks
Adam
 
You must log in or register to reply here.
Back
Top