docauto

Hi, I'm new to this forum (2001 3500 6-sp 275 injectors added when new and adjustable wastegate elbow just added), but I've spent about 5 hours looking thru old postings looking for info, this is a great resource!

I had an interesting failure mode on Saturday on a 1300 mile one-day trip: I noticed a slight high end miss, figured the lift pump was getting tired (second pump on the truck, now has about 100k on it!!), filter replaced 30k ago. Upon pulling off the road, the idle was 1200+ and the accelerator pedal stopped working (no response at all, couldnt maintain any speed, running at high idle only). I turned off the truck for a few seconds and restarted, idle was normal (850) but still no pedal response. Turned off the truck and waited about 10 seconds and all was fine. Now I was thinking APPS... All was fine for a few hours with a very occasional high end miss, I was slowing for traffic and the pedal again went completely dead (of course on a mountain road, had to pull over on a blind corner), turned off truck and it reset fine. I was able to get home OK. The high idle symptom has occurred a few times starting about 6 months ago, it always resets after restarting.

Check engine light on, Trouble codes are P1693, P0121, P0234. I assume the P0234 and engine light on are due to the wastegate elbow mod (I'm hitting 27 PSI, I think P0234 triggers about at that pressure). I haven't put on the LP pressure gauge yet, figure I'll do that this week. I also have the big line and LP relocation kit that will go on at the same time.

Any suggestions? Am I scrambling the processor in the VP44? Can a turbo overboost trigger some weird pump symptoms? Is it simply a lift pump going bad? The truck is starting and running fine. Hope it's not a VP44....

I look forward to your responses!! Thanks!!! Dave

graphitecumnz

P0121 is a code for the APPS... try the reset in the tech facts section but you may be buying a replacement soon.

piperca

I have yet to hear of someone being successful with the APPS reset procedure, as outlined in the tech facts. Resetting the sensor to the correct voltage is the only way you're going to get rid of that code ... or replacing the unit ... been there, done that!

graphitecumnz

neither have I but I figured it must be there for some reason... never worked on my truck.

crobtex

It can work, I've done it, but it's usually a temporary fix.

Andy505

I've done the APPS reset procedure as well...it has worked for me every time it tried it.

docauto

UPDATE: I installed the FP gauge and big line kit last night, and at idle it's reading 16+, On the road wide open (27PSI boost) it's at 14. Looks like my 100,000+ mile lift pump is OK! I'm keeping a spare with me just in case. Hopefully the VP44 is still happy (it makes me feel better that the LP is fine)Now I'll start chasing down the APPS. I tried the reset (batteries disconnected for 2 hours), but the codes have not reset and the engine light is still on. Is there a better reset procedure?

Thanks

Dave

BigBlue

Wow. 100,000 mile lift pump is unheard of. Especially one that's putting out those numbers. That's very, very, very impressive.

crobtex

My first one went 120k + miles. The second, only about 40k miles. FASS II....who knows.........

docauto

The first one only lasted 30k and the dealer replaced it with the Carter, I just bought another for a spare. With the relocation and big line kit, changing it will be a breeze!

CTD NUT

docauto,

You are getting the 0234 because you are not using a boost fooler on the ECM. The ECM will defuel at 20 psi regardless of what has been done to the wastegate. You will see more power, responsiveness and eliminate the 0234 DTC if you do not allow the ECM to defuel.

All aftermarket fueling modules witha a MAP connection have an integeral boost fooler or, if you don't want a fueling box, you can get stand alone boost fooler called the ADD.

docauto

Thanks CTD Nut! I have a Van Aacken box that I have not used since the truck was new, I really didn't "need" the additional power. Now that I added the wastegate elbow, should I reinstall the box? I'm not knowlegable enough to know if the Van Aacken has an integral boost fooler. Is the MAP connection different than the connection at the IP? Sorry if these questions are obvious, I'n new to these type additions.

Thanks for the help!!

Dave

CTD NUT

Dave,

The MAP connection is not a connector at the injector pump.....it is part of the VA harness that tee's into the MAP sensor harness at the back of the engine on the drivers side. Incidently, I have been told that some of the older first generation VA boxes do NOT have a MAP connection and therefore do not offer boost fooling capabilities.

docauto

Yup, I believe you're right on the money. I just connected the Van Aaken box and found it works very well up to 20psi, it falls down (defuels) at greater than 20. My box is old (2001, purchased when the truck was new) and there's no other connection other than the IP connector. I emailed Van Aaken to see if there's any fix other than purchasing a new box (no reply as of yet). If a replacement box is necessary, can you suggest a good one?

Thanks again for the reply, it really helps!

Dave

CTD NUT

I don't think there is anything VA can do to your existing box to allow it to accept a MAP connection....but we'll see what they have to say.

As for other fueling box suggestions, I would suggest an Edge Comp. It offers the most bang for the buck. It is a wire tap box which is the only way to get biggest power gains from a fueling module, has 5 adjustable power levels with each power level having 5 adjustable rates of fueling (sub levels). It can also operate in what is commonly referred to as "EZ mode" in which the wire isn't tapped. In this mode, the adjustable sub levels function for the rate of fueling but it only offers one overall power level which is not adjustable and offers comparable power gains to another Edge box called the EZ. The EZ is not a wire tap box and offers a one level, non-adjustable power gain of about 60 hp. Since the Comp is typically only about $100 more than the EZ, can be set up to run like the EZ (with more adjustability) but also offer MUCH higher power gains with the pump wire tapped(should the desire arise ), IMO, it is the way to go. A 3rd option is another VA box. They are usually priced a bit less than the EZ but offer similar power gains.