tig

I have a 1998.5 cummins. It,s been a long time since i messed with a diesel. The question is I think my tps sensor is bad. I have no codes but sometimes i step on the throttle and nothing happens but then it takes off. The truck has 28000 miles on it and it is bone stock.You guys seem to know what's going on, I need help on everything like why is the need for a fuel pressure gage,what's the best performance computer,exhaust,air cleaner,etc.thanks alot for any help.Tig

Clunk

Welcome to the site ,
Your Dodge/Cummins has fuel milage and power capabilities far beyond a basic gasser but it isn't gas-n-go like a gasser either...it's a bit involved but not difficult to manage.
Obtain a repair manual at your favorite auto parts store so you can get up quick on your truck but get a factory service manual if you're going to do most of your own repairs & adjustments.
You also need gauges to get info from your truck but more on that later..
Your 24 valver has a Lift Pump that takes fuel from the fuel tank and delivers it to your Injector Pump(VP44). This VP44 is the weak link and because it's so expensive, it deserves extra consideration.
For years the guys here have been trying different things to get the VP44 to live and through basic R&D, they've discovered a few things that help most and are running up the miles.
Fuel lubes and cools the VP44 and we watch that with the Lift Pump fuel pressure. We generally like to see 13-15psi idle, 12-13psi cruising hwy speed and no less the 5-7 psi at wide open throttle(WOT) stock. A pressure gauge installed in the cab, connected by pressure line to the outside fitting on the top of your fuel filter housing will get you lift pump fuel pressure to watch.
Diesel fuel has very little if any lubricating abilities so fuel treatments like Power Service, Howes, Lucas and Stanadyne add lubrication to the fuel. I use the MFG's recommend on dosages.
There is fuel returned to the fuel tank from the fuel system and because some of it comes from a passage in the cylinder head of the motor, it's hot. This is fine in the winter because diesel fuel can gel in very cold temperatures BUT in the summer, it can get hot enough that it won't cool electrical components in the VP44. Most folks are keeping their fuel tank 1/2 full or better. We're currently looking for an end all fuel cooler that does not restrict flow or pressure.
Many folks have found that they had no lift pump pressure after they install a gauge or change the fuel filter so be ready for that.
Type "lift pump" in the search box for lots of info.

You can check the electrical connector to your TPS, what Cummins refers to as an Accelerator Pedal Position Sensor (APPS) to be sure of a good electrical connection.

tig

I really appreciate the help clunk. The info was really great.I hope one day I can return the favor.Thanks again TIG

tig

Hey Clunk I was reading about fuel cooling problems, years ago when we drag raced we used a cool can, but i think if you use a small transmission cooler mounted if front of the radiator, running the fuel through the cooler and back to the injection pump might do the trick, or small transmission cooler with a small fan. TIG

Clunk

I'm leaning in favor of a finned cooler on the fuel return line so's not to impair the lift pump pressure or flow. The return line runs along with the supply line on the frame rail so the plumbing would not be a problem. I'm not crazy about running fuel lines outside the designed routes for fire safety in the event of a wreck.
A transmission cooler would be "cool". A trans cooler w/fan would really be cool.
Have you checked your fuel pressure today?
Fill out your signature so everybody will know your truck info if you have a problem.

tig

Thanks for the reply clunk
I haven't checked the fuel pressure.I went to the local truck store to order some guages,boost,pryometer,and a fuel pressure guage.The price came to 518.00 dollars.I thought this was rather high.What type of guages do you all run and how much.I was thinking of just getting a fuel pressure guage and maybe a controller that has digital boost and pryometer built in. does this sound ok. Thanks TIG

Clunk

Tig, my truck had the boost and pyro already installed when I bought it.
My 0-30 psi lift pump fuel pressure gauge was given to me and was checked for calibration....reads a 1/2 low. The lines and needle valve are straight from my favorite auto parts store and sealed with permatex non-hardening sealer. Check my pictures.
The site sponsors have some good gauges much less expensive than the prices you were quoted.
When I buy a vehicle with an automatic transmission, I change the filter and refill with new fluid first thing.

tig

THanks for the reply Clunk
I went and ordered a hyperpac controller today,one that has all guages and everything built in,cancelled guages. I'am trying to figure out how to put all my info about my truck on the bottom of my page like you guys. THANKS, TIG

Clunk

Find "User CP" and click on it.
In the settings and options box, click on "edit signature" and fill it in.

J BODY

I would also recommend that you have your ECM and JTEC controllers scanned for any codes. You may be experiencing "dead pedal" which can be associated with a p0216 pump timing failure which always is associated with a bunch of money leaving ones pocket.

tig

I'am going to try to rig me up a test guage and see what my lift pump pressure is. I'am going to talk to my cousin who works at the chrysler garage to see if he can get me a manual. What is the best replacement pump,aftermarket that is. My step son works part time at the local chrysler speed shop and i asked him to get me a price on a tps sensor for a cummins, he said his price would be around 60.00 dollars. I asked are you sure.He said yes, I haven't seen it yet. If it is the right part I'll let you all know. I still think it is a mix up.Thanks TIG

Clunk

$60 for a Accelerator Pedal Position Sensor (APPS is TPS in Cummins diesel speak)? Don't fergit ta git one fer yer ol' buddy Clunk
My $90 Carter 4601hp is from Summit and been in service 2 years this Sept. mounted by the fuel tank. Geno's has a complete line and relocation kit.
Some of the guys here haven't been getting the same life outta theirs and I wish I could help.
The guys with the FASS pumps seem to get good service.
I'm real peculiar about filling the tank with the handle on the slow notch so's the despensing pump filters can do their job. Fuel conditioner with every fueling.

tig

I'am going to see if the tps sensor came in tomorrow. I got a question, can i hook up a electrical fuel pump and keep the stock lift pump hooked up.Next question, The ports on top of the fuel filter bracket, one is a test port before the filter and the other is after the filter, where do i check fuel pressure,after the filter. If the price is right on the tps sensor I'll get you one. Thanks Tig

Clunk

Grab the post filter port, we want to see the pressure being supplied to the injector pump$$$. It's the most forward port on the filter top.
There are folks running tandem pumps with kinda high fuel pressure. There are kits available to do this but then you have 2 pumps....
The Fass guys run a single pump at the fuel tank with apparently good results.
I'm having good results with my single Carter 4601HP at the fuel tank but others have had problems with bad pumps and shearing impeller keys.
The TPS/APPS might have to be calibrated, your cousin should have info.

From Dodgeram.org:
The 98.5 - 2000 APPS carries Cummins part# 4002066
The 2001-2002 APPS carries Cummins part # 3937162

tig

The tps sensor came in today as usual it was wrong.I'am going to try to hook up a simple fuel pressure gage to check things out till my hyperepac system comes in. Hopefully I'll get to it this week. Thanks for the help clunk. By the way the plug on the filter housing is it american pipe thread. thanks TIG