Please help I'm at end. I just got 3/98 24valve and I'm trying to find out why it starts it right up, idles great and when you give it throttle in park for drive don't matter Motor doesn't go above 1500rpms . Got a code reader and it came up with what seems to be Dreaded P1689 code

Which far as.I can find is something NO ONE agrees on of the cause!!

I found this site from another diesel guy and I link I was given was here for 24valve 50\51 engine/obdii-error-codes94/P1689no-communication-between-ecm-and-vp44-r35/

I went through link and was able to get all way to #5 test which is checking ohms between #2terminal on FORM which is Supposed to be a "White Wire" and #13 on the ECM harness connector.

Well I don't have a White Wire anywhere in the rpms harnes. So I can't go beyond this test

At my shirts end and really don't want to have to pay mechanic $200 just to tell me what's wrong then whatever it will be on top of that.

Really need help

Also in reading and watching, remember something about it after fuel filter change that whatever is wrong will make it super hard to start. Getting fuel bled and fired up again. Now after changing fuel filter now seems that I'm having that issues also.( Battery started to run down so couldn't crank a lot to get fuel back up. After full day doors.open key switch on off alot .

Had to stop and charge up battery. I might get it started but still don't know why it not acting like the Raped Ape a 2nd Gem is Supposed to Be!!

Help please

Only has 113845 miles on it . Transfer pump relocated to in fuel tank.

Not sure what other help I can give at.moment. I need help though

Like most of us I ain't got a lot in life good wife great.daughter, he'll of a dog and not much $ especially just to have someone say it's this part that be $200 oh and if you want me to fix it, it will be X amount times 3 more plus cost of part

Y'all know the deal?

Thanks in advance for Any help

 

Its been a few years since I messed with a second gen but for vp44 and general fueling issues Blue Chip Diesel is a good go to spot.

https://www.bluechipdiesel.com/knowledge-center

Not sure if they still do but used to be pretty good customer service via phone as well.

Might be worth a look and or a call

 

Thank you for the info BarryG I will check it out today. This is giving me fit

 

Thank you for the info BarryG I will check it out today. This is giving me fit
did a fuel pressure test and when I ignite the electric in tank fuel pump I get 10lbs of pressure. When I crank it it.goes down to roughly 5lbs or lower longer crank. When pump stops.ots cycle gauge goes back to 10lbs. No more only less when cranking. Now after changing fuel filter while diagnosing. Now truck wont start to save my life. So thinking this confirms lift pump in crank is bad and causing all the issues.
does this sound correct?

 

Have you confirmed that you have fuel coming out of the injector lines. Ie bled them, easy to do if you haven't. Start at the first one loosen it (at the engine not the pump )no need to remove it just loosen it a bit. Crank engine until fuel starts coming out (bumping the starter to get the lift pump to run will not bleed the injector lines it will fill your fuel filter canister and get fuel to the vp44 but not beyond). Tighten move to the next one repeat., I never had to do more than three. This will ensure that your system is bled and the injectors are getting fuel. Now if you cant get fuel after cranking a bit . obviously another issue as to why it is not getting fuel but I would do that first

I never had an in tank pump and I believe they don't put out a ton of pressure but 10psi is plenty to get it started even dropping to 4 or 5 is still plenty to get it started and running.

 

If it starts up and runs, it has fuel. I'm willing to bet the VP44 is fine, especially since it starts, runs, and revs up some.

The intank pump is not a good pump to have. It didn't do any better than the pump it replaced that was mounted on the block.

Tells us more about your fuel system. Other than knowing you have an intank pump, what other modifications are there?

Right now from the limited information, I suspect a comms issue between computers

 

I only mentioned the bleeding the injector lines as he stated while diagnosing it he changed the fuel filter and now it wont restart. Once he gets it started again then he can more properly diagnose/test what is really going on didn't want him chasing his tail on the no start if air locked is even the issue with the no start. It does sound as you said like some sort of comm issue

 

Having to retype all this again. Code is No Communication between ECM & Injection Pump Module Code: P1689
P1698 No CCD messages from TCM
P1693 FLT in Comp. Module
these are only 3 codes .

As far as starting issues .thank you for telling me to keep bleeding all way to 2nd or 3rd injector if need be. I had to do 1st 2 then it tried.to crank. Hit starter again & it fired up. It runs great @ idle and sounds like it supposed to be really healthy when you give it throttle well then it only goes to 1500rpms. This truck is stock and Only has 138,400 miles on it.
so I am stuck . Not knowing enough to know what's wrong without keep throwing $$ at which I definitely dont have and knowing enough to be dangerous. But also know when I am at end of my capabilities on diagnosing what from here. . I havent done fuel pressure test since I got truck running with gauge on during running( got to late).
starter engaged to engage fuel pump I get 10lbs of pressure. When I cranked it it went down around 5 maybe little kower.( mind yall I did this test whtest after bleeding air un lines , but couldn't get it started at this point cuz I didnt bleed at injectors like I was told and that worked . So now if I need to do fuel test.while run ing to help diagnose this. I have it running and can perform. But if yall think it's not Fuel delivery issues! I'll gladly take $150.00 rental gauge back and give it back to wife. But if I need to hold onto to it for little bit longer to do more fuel testing I will.
thank All of yall for the help. I really appreciate it

 

BarryG helped out bigtime with telling me to bleed at injectors

Also there is No modifications to motor hat I know of other than it was changed in an in tank at some point

 

If you still have the gauge, attach it, start engine and read fuel pressure at idle, try to rev and note if fuel pressure drops.

Please report the values that you read, and describe what the truck does, maybe take a video to let us see and hear.

 

this was only way I could figure out how to get videos that yall can warch( Hopefully) it works.
I got pressure gauge hooked up. 10lbs pressure running @ idle or on throttle bo changes.
while doing test.i noticed if barely touched theottle( under hood) it kind bucked. Almost like in between signals (throttle cable being moved and maybe throttle position sensor Maybe? But it bucked several times with really trying g then I noticed and was able to duplicate but it was super hard.to Only give it That LITTLEof touch on cable to not.gi e.to much where it went straight to 1500rpms( basically wide open)
Humm wait does that make sense?? Could it be throttle position sensor ( maybe only registering idle or wide open @ 1500 rpms or which Happens to be 1500rpms.
Is this possibility? With a Code of P1698???
happen to think of that until right now as I was typing this. So fuel pressure stays @ 10lbs running idle or throttle
Which I Only have 2 Throttle Positions @ Idle.OR it.goes.straight to 1500rpms No matter.if I get.it a Littlw bit more throttle or if I give.it all it has its still Only.goes to the 1500rpm mark.
other than that. Dam truck sounds like it should be Strong running . I do know owner was meticulous about his behicles.and keeping them running and tuned and all that. So sometime roughly.1 year ago. Husband passing and it's been sitting till I got it idle or 1500rpms. It was parked by husband 6 months before they had driven it around and it ran normal like that truck Should RUN!!, they went up north.come back few.months later.and it fires up but only went to 1500rpms. . He left it alone then he passed away. Fast.foward a.yeat maybe less.. now I have it.
I dont know if any of this helps,??
What about Throttle Position Senaor?
And it Only having basically 2 settings. Idle & 1500rpms
it that maybe the cause of all this? If so then why does it not.throw a Code for that & Not forNNo Comms between ECM and Injection Pump Module Code P1689
other code is No CCD messages from TCM Code P1698 , & last.Code is P1693 FLT in Comp MDLE
near as I gather 1.of the last 2 codes just means there is a code thrown .
But I cant find out Figure out what paet.i Need.to change to not have P1689 code. What paet does that say it culprit or what is that is throwing those codes

 

A small excerpt from Timbo's page
With the paperclip provided insert it into the back of the connector PIN # 3 (Green wire). Or insert it into the back of the factory plug(light blue wire w/black tracer) just make sure its PIN #3. This will get hooked to the positive lead of the voltmeter. The ground lead can be hooked to the ground terminal of the battery. Turn your voltmeter to the low voltage DC scale. Make sure paperclip does not contact ground. Proceed to plug the sensor into the factory harness and then hook the batteries up. Turn the key to the ON position. Now read the voltmeter, it should read .580-.700.

OK, follow these instructions, and sweep the throttle from idle to WOT, watch the voltage readout. It should go smoothly from the idle voltage up to the WOT voltage around 3.8V -
if you notice any jumps or drops you will need a new APPS. (I recommend Timbo's version)

The no comms is still an issue, but do this test first.

 

Ok working in it with a video

 

here are the 2 videos of APPS(throttle position sensor
I hope this helps yall be able to help me .
Really dont want to have to take it to shop. Cannot afford.that especially right now
that's why I'm so glad.i found yall on this site

 

OK, maybe it's your meter or the connections, but in the first video around 1:30 I see voltage dropping out.
Maybe re-verify it, and take a look at it with the engine running, and when you provoke the hickups.
Here's a wiring diagram for a 2001.
The second video seems to be the idle validation switch, please check that the contact 2 goes to ground as soon as you move the sweeper a tiny little bit. Also Pin6 needs to come up to approximately 5V at the same minimal movement.
This switch tells the engine that it's at idle, or that you want power. You can calibrate the behavior with the APPS reset method. Disconnect both batteries, turn ignition key to run, wait 30 minutes. Turn key off, reconnect batteries, turn key to run, slowly depress accelerator pedal to WOT, release slowly, turn key to off. The APPS is recalibrated to the ECM.