Engine/Transmission (1994 - 1998) help: '97 with low power

[Advantage Take]

after installing some gauges over christmas i noticed low power. drives alright while not loaded, but it feels like a horse could tow a trailer faster when towing. here are the numbers at 65 mph unloaded:



600-800 EGT

3-8 PSI Fuel Pressure

3-7 PSI Boost



its got a 215 pump and used to be an amazing truck while the trailer was hooked up. i'm planning on doin some work this weekend with it, might take it down to Garmon's south of atlanta so i would like to figure out whats going wrong before i turn it up a little. any idea's???

 

[REFLOYD]

Overflow valve probably needs to be replaced. it sounds like the fuel pressure is low. could also be a dirty fuel filter. check the filter first. also check the air filter. And check the boost hoses. if the truck is mostly stock your egt reading is a little high for just cruising at 65. That is where mine runs at and i have the 370 injectors

 

[WDixon27]

i just changed my lift pump and picked up a nice power increase, it'd idle at 20-22 psi but any throttle even out of gear and it would drop, i could pull it down to 14-15 psi under load but it seamed to run good and just pulled 248 hp on a mustang dyno, a new pump had it idling at over 25 psi and would peg my 30# gauge almost instantly, i have a 60# gauge on the way so i can keep a eye on it for problems, 2250 rpms in 5th (should be 70 mph reads 65-66 with 235/85/16s) 3 psi boost 650-700* egt on flat ground all mods listed in sig

 

[DBraunig]

AT,



if that fuel pressure reading is accurate (3-8 psi) you definately have a fuel pressure problem. normal fuel pressure on a 12 valve at idle is 18-22 psi and 25-35 psi at 2500 rpm. Here is a link to Dave Fritz's site that can help you diagnose the trouble, http://dodgeram.info/tsb/1996/14-07-96.htm.



Good Luck,



Dave

 

[Advantage Take]

Sounds like i need to check the overflow. both fuel and air filters are fairly new. also, there are no visible leaks which points towards the overflow again. where can i find a new one. i'm in chattanooga, tn for this week and i've seen a few cummins big rig shops but would they have them? thanks for the help.

 

[WDixon27]

it's easy to check for basic operation of the OF valve it's just a ball and spring, make sure the spring is not broken or collapsed it should be around 1/2" long, you should hear it buzz after mashing the primer a few times, maybe get someone to look at the fuel pressure gauge while you hit the primer and see if you are building some good pressure. on my truck the OF valve had no spring or ball at all and was passing all of the fuel pressure back to the tank, and was a pain to start cold unless you hit the primer a few times

 

[Advantage Take]

yea, there is definately a buzzing sound when i hit the primer. it builds pressure to about 20psi. i'll see if one of these big rig shops has an overflow valve for it. thanks for the help guys.

 

[San Felipe Bob]

Sounds like you might need to clean the primary fuel filter.

It's below the primer.

It's a small bowl with a metal screen.

SFB

 

[Advantage Take]

well, the overflow valve is good, had it tested. since the lift pumps have such a good reputation for being reliable, i'll rule that one out for the moment which leaves me with the pre-filter/heater assembly, the filter in the tank, and the fuel lines. tommorrow i'm going to check the fuel heater assembly and maybe replace the fuel lines in the engine compartment. any good tricks to get the fuel heater assembly out?



thanks for the help,

michael

 

[REFLOYD]

when i fix a small leak that mine had i removed the starter then reached up from the underside and unscrewed the bolt that holds the prefilter in place. the heater can then be removed with an allen wrench.

 

[Advantage Take]

well, i've decided to bring it down to jeff garmon in atlanta seein as i needed some pump work as well. i just don't have the tools or time to handle it right now. thanks for all your help. i'll post again when i get it back.

 

[REFLOYD]

that is what i was just about to post and tell you to do. I will probably be taking my truck up there at the end of the summer.

 

[Advantage Take]

its done

picked up the truck from garmon's this afternoon and i'm still amazed. he put on a new exhaust, governer springs, plate forward, and fixed the fuel pressure problem(happened to be a completely clogged fuel filter that was supposedly changed not 2000 miles ago). i have nothing but praises to sing for his shop. while i was there i saw atleast 3 trucks with a 500+ hp badge on them. it doesn't matter if you want to add a little power or a lot, garmon can do it.



another happy customer,

michael

 

[RDelissen]

a good tune up and check ENAT doesn't hurt and makes both the Dodge and its owner happy

 

[Matthug]

1 batch of bad fuel can clog a filter... . how often do you drain the water/fuel seperator?