Engine/Transmission (1994 - 1998) Jeffrey Howes

[Jeffrey Howes]

My truck reciently started bogging down if you press the accelerator more than 1/4 of the way it is particually bad in the morning when the truck has not completly warmed up. Sometimes it will stall out, I talked to a Geno's garage tech and he said to replace all the fuel filters I did this, "they were not very dirty at all". still no change, the truck is a 12 valve auto. Should I tackle the lift pump next? If anyone has had this problem and solved it any help would be greatly appreciated. also revs fine in Neutral but boggs right out when you get on the accelarator, can drive truck normally when warmed up as long as you don't go past 1/4 -1/3 throttle

 

[budnate]

have you made sure your fuel solenoid is going full open?

sounds like its short on fuel if that checks out look into the fuel press.

your overflow valve may be done, they make a nice adjustable one now to dial in fuel press highly recommend one.

use the search function on this site, tons to read on both subjects

 

[Jeffrey Howes]

Jeffrey Howes 12 valve bogging out

How do i check if fuel solinoid is opening all the way, also rpms jump but no power. I read about the overflow valve in the TDR buyers guide. truck has 270,000 miles original lift pump. Also Revs right up normally in neutral. Thanks for the response.

 

[budnate]

located on the driver side find it and turn on the ignition to the start and go see if it lifted all the way, better yet have someone else do the key and you watch it, help it up with your fingers if it lifts up a long ways like a inch or two find some wire, wire it full up and go for a drive, if it runs right you found the issue.


http://www.fostertruck.com/2-1-2-dodge-fuel-shutdown-solenoid-fix-kit.html

 

[GAmes]

You are in dire need of a good repair manual. Don't waste your money on Haynes or Chiltons. Get a factory service manual here. http://www.genosgarage.com/

 

[Jeffrey Howes]

thanks for all your help, BudNate, I knew about the fuel solenoid , but didn't know it could partially fail.

 

[Jeffrey Howes]

GAmes, I do have a factory service manual, but it doesn't say anything about the fuel solenoid partially failing, or maybe I missed it.

 

[GAmes]

GAmes, I do have a factory service manual, but it doesn't say anything about the fuel solenoid partially failing, or maybe I missed it.

Since you posted "How do i check if fuel solinoid is opening all the way" I interpreted you didn't have a manual. I supposed you didn't know what or where it is. Sorry.

 

[Jeffrey Howes]

Turns out it's the P7100 over-flow valve I pinched off the line and took it for a very short spin and truck runs as it should.
I'm sure this is not the ideal test but figured that if I just did a very short test it would be OK. Thanks for your replies, GAmes

 

[Jeffrey Howes]

BudNate, it's the P7100 over-flow valve, you mentioned that they make a adjustable model. Can you give me information on who offers that product, And how you dial it in to the proper adjustment?

 

[Jeffrey Howes]

Woops. Guess I'm not very observant, I see now that you said to use search function on this site. Again thanks for all your help.

 

[GAmes]

Non-adjustable OEM http://www.genosgarage.com/BOSCH-FUEL-OVERFLOW-VALVE-KIT-94-98-12V/productinfo/2-417-413-101-KIT/



adjustable http://www.fostertruck.com/adjustable-p7100-overflow-valve.html

 

[budnate]

thats the adjustable unit, I cant recall who but a place in Oregone had a test gauge kit for sale priced real fair, you will want one they come in handy,



set the fuel up for about 23/25 at idle and go for a run the gauge has a long hose option so you can hang it by the wiper or I ran mine over by the driver mirror to hold onto it and watched it, when you really romp on it to make sure you have good fuel psi under heavy load.

 

[Jeffrey Howes]

Yea I need a test gauge. i'm starting to get as frustrated as I was when my new Borgeson steering box blew up on me after 30 miles pretty much fried my power steering pump and, I had to wait till they sent me a new box, ended up being a torn O ring in the box, warranty item. Anyway , I got the adjustable over flow valve and installed it still no change, so I pinched off the return line again with some straight jaw locking pliers padded with many many layers of electrical tape. Took it for a spin and it ran great. Why? So I bottomed out the adjustment on the overflow valve, that made it a tiny bit better. So my question, why do I need an over flow valve on the extremely detuned stock P 7100 injection pump? Why can't I just put a plug with some gas thread tape or a sealing washer in that over flow valve hole? Guess your going to tell me I need to replace the transfer pump, something I do not look forward to doing. My fear is I replace the transfer pump and it still runs wrong. What's the risk in just plugging the over flow hole? What damage can might occur?

 

[budnate]

don't want to sound rude, but you have to get a gauge on the system and see where your at and make the proper adjustments, guessing don't cut it... ... ... ... kits are only $55 bucks.

http://www.genosgarage.com/VULCAN-P...-02/productinfo/VULCAN_TEST_KIT/#.UlYTLVOorms

 

[Jeffrey Howes]

Once a trial and error guys always a trial and error guy.

 

[Missouri Mule]

When you do the fuel pressure test at idle you should be getting over 20 psi if your not( pressure should go up in the 30's when raise the idle to 2000 rpm) squeeze the return line like you been doing. If the pressure goes up it is your overflow valve, if it does not go up or goes up slowly it is your transfer pump (lift pump).

At the mileage your at it could be either one or both. I had my lift pump replace btween 285,000 and 287,000 (Mule died in the driveway) three weeks later Mule died again in driveway replaced overflow valve (ball was getting stuck in it). It ran good after that but had bad stumble when first started. Change fuel filter all was well.