Advertisement
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Home Who's Online Today's Posts HP Calculator CompD Gift Shop Mark Forums Read
Go Back   Competition Diesel.Com - Bringing The BEST Together > Tech- General Diesel > General Diesel Tech
Register Members List Timeslips EFI Live Library Invite Your Friends FAQ Calendar Mark Forums Read

General Diesel Tech Farm equipment, Medium Duty, Big Rigs, and other General discussion can be found in here.

Closed Thread
 
Thread Tools
Old 09-16-2021, 11:31 AM   #1
SCHMITTY
 
SCHMITTY's Avatar

Name: SCHMITTY
Title: Not enough time
Status: Not Here
Join Date: Jun 2012
Location: K beach, AK
Member`s Gallery
Posts: 1,177
Just bought a 1988 kw w900

Seller had the head gasket replaced and said it probably needs injectors.

It has the ntc 444 and i think the stc is not working correctly. Anybody have tips for checking the stc system ? I’ve been reading through old forum posts online.
Attached Images
File Type: jpeg 1BD7A46E-A64C-439D-8C7B-B22767304249.jpeg (85.9 KB, 0 views)
__________________
stock 94
 
Old 09-16-2021, 12:02 PM   #2
Snedge
 
Snedge's Avatar

Name: Snedge
Title: Comp Diesel Sponsor
Status: Not Here
Join Date: Sep 2006
Location: Western Pa.
Member`s Gallery
Posts: 18,832
Nice find.

If the step timing control isn't working it'll smoke at idle. There a a handful of causes for the malfunction. What's up with it symptom wise ?
 
Old 09-16-2021, 01:07 PM   #3
SCHMITTY
 
SCHMITTY's Avatar

Name: SCHMITTY
Title: Not enough time
Status: Not Here
Join Date: Jun 2012
Location: K beach, AK
Member`s Gallery
Posts: 1,177
White smoke at idle and smells of diesel fuel, occasional mis, smoke seams less noticeable maintaining speed on the highway , under full throttle there’s black and grey smoke. I have felt the miss at highway speed. It has been sitting for a few years. I’ll get a t made up for testing the oil pressure before and after the stc valve , probably run the overhead next doing obc method, check the cam lift while I’m in there with my dial indicator and magnetic base. Im not opposed to buying a new stc valve and injectors but I have thrown money away without trying to diagnose in the past and that always ends badly for me.

Ill take a cold start vid and a operating temp vid in a hour or so
__________________
stock 94
 
Old 09-16-2021, 01:15 PM   #4
mhuggler

Name: mhuggler
Title: One piece at a time
Status: Not Here
Join Date: Sep 2007
Location: Uno, Pa.
Member`s Gallery
Posts: 1,521
Quote:
Originally Posted by SCHMITTY View Post
Seller had the head gasket replaced and said it probably needs injectors.

It has the ntc 444 and i think the stc is not working correctly. Anybody have tips for checking the stc system ? I’ve been reading through old forum posts online.
Sweet truck; I’ve always liked W900’s. Personally I would spend as little as possible on that 444 and save for a 3406 Cat 425. Look for a 4MG serial prefix. You can’t beat the legendary “four and a quarter”. I was raised on Cummins, the first engine I ever built was a small cam 855. I’ll always love Cummins but Cat really is the best.
__________________
2002 2500 4x4 ETH/DEE-F1 Mach 5's/62/65/12/Smarty/ATS Ex.manifold/AFE intake/TST Comp./.020 marine gasket/o-ringed/ARP studs/5"stacks/Airdog 150/Isspro guages/Southbend 3600 DD/3.54 gears/leveling kit/Bilstein 5100frt,5150rr/37" BFG A/T's on 18" Eagle 114's/Borgeson SS/DSS
 
Old 09-16-2021, 01:16 PM   #5
Snedge
 
Snedge's Avatar

Name: Snedge
Title: Comp Diesel Sponsor
Status: Not Here
Join Date: Sep 2006
Location: Western Pa.
Member`s Gallery
Posts: 18,832
A lot of time the STC system is okay, and oil pressure is the culprit. The system is supposed to fill a void under the injector link with oil to advance timing at idle to eliminate the raw fuel smoke. If you touch the fuel pedal enough to bring oil pressure up 5-10 PSI see if the smoke goes away some. Could be a cracked piston cooling nozzle, or a leak in the internal oil manifold plumbing.
 
Old 09-16-2021, 01:17 PM   #6
Snedge
 
Snedge's Avatar

Name: Snedge
Title: Comp Diesel Sponsor
Status: Not Here
Join Date: Sep 2006
Location: Western Pa.
Member`s Gallery
Posts: 18,832
Quote:
Originally Posted by mhuggler View Post
Cat really is the best.
Bullshit.
 
Old 09-16-2021, 04:26 PM   #7
mhuggler

Name: mhuggler
Title: One piece at a time
Status: Not Here
Join Date: Sep 2007
Location: Uno, Pa.
Member`s Gallery
Posts: 1,521
Quote:
Originally Posted by Snedge View Post
Bullshit.
Hey, it did take me a while to admit it at least.
__________________
2002 2500 4x4 ETH/DEE-F1 Mach 5's/62/65/12/Smarty/ATS Ex.manifold/AFE intake/TST Comp./.020 marine gasket/o-ringed/ARP studs/5"stacks/Airdog 150/Isspro guages/Southbend 3600 DD/3.54 gears/leveling kit/Bilstein 5100frt,5150rr/37" BFG A/T's on 18" Eagle 114's/Borgeson SS/DSS
 
Old 09-16-2021, 05:26 PM   #8
jasonc

Name: jasonc
Title: Too Much Time
Status: Not Here
Join Date: Nov 2009
Member`s Gallery
Posts: 4,396
Quote:
Originally Posted by mhuggler View Post
Sweet truck; I’ve always liked W900’s. Personally I would spend as little as possible on that 444 and save for a 3406 Cat 425. Look for a 4MG serial prefix. You can’t beat the legendary “four and a quarter”. I was raised on Cummins, the first engine I ever built was a small cam 855. I’ll always love Cummins but Cat really is the best.
I still have fond memories of the 3116 I had in a Kodiak, Not.
Was an over heating pos they never could fix under warranty, they just patched and rhode me out until it was over.
 
Old 09-16-2021, 08:55 PM   #9
SCHMITTY
 
SCHMITTY's Avatar

Name: SCHMITTY
Title: Not enough time
Status: Not Here
Join Date: Jun 2012
Location: K beach, AK
Member`s Gallery
Posts: 1,177
Quote:
Originally Posted by Snedge View Post
A lot of time the STC system is okay, and oil pressure is the culprit. The system is supposed to fill a void under the injector link with oil to advance timing at idle to eliminate the raw fuel smoke. If you touch the fuel pedal enough to bring oil pressure up 5-10 PSI see if the smoke goes away some. Could be a cracked piston cooling nozzle, or a leak in the internal oil manifold plumbing.
It clears up under higher rpm. The smoke dies down a little but 75% of the time it is pretty bad. The worst seems to be when I come to a stop and it’s at operating temperature. The oil pressure is 80-100 on a cold start , drops to 25 when warm, 40-50 cruising. YouTube won’t let me sign in. I took some videos when I had it out today.
__________________
stock 94
 
Old 09-16-2021, 08:58 PM   #10
SCHMITTY
 
SCHMITTY's Avatar

Name: SCHMITTY
Title: Not enough time
Status: Not Here
Join Date: Jun 2012
Location: K beach, AK
Member`s Gallery
Posts: 1,177
Quote:
Originally Posted by mhuggler View Post
Sweet truck; I’ve always liked W900’s. Personally I would spend as little as possible on that 444 and save for a 3406 Cat 425. Look for a 4MG serial prefix. You can’t beat the legendary “four and a quarter”. I was raised on Cummins, the first engine I ever built was a small cam 855. I’ll always love Cummins but Cat really is the best.
He had a 93’ t800 with a flat top sleeper and a 3406. He wanted 2.5x as much for that one and it was kind of beat up. Idled smooth though
__________________
stock 94
 
Old 09-16-2021, 11:21 PM   #11
SCHMITTY
 
SCHMITTY's Avatar

Name: SCHMITTY
Title: Not enough time
Status: Not Here
Join Date: Jun 2012
Location: K beach, AK
Member`s Gallery
Posts: 1,177
First start of the day. The wind made it hard to catch a cloud of smoke on video


- YouTube
__________________
stock 94

Last edited by SCHMITTY; 09-16-2021 at 11:23 PM.
 
Old 09-16-2021, 11:24 PM   #12
SCHMITTY
 
SCHMITTY's Avatar

Name: SCHMITTY
Title: Not enough time
Status: Not Here
Join Date: Jun 2012
Location: K beach, AK
Member`s Gallery
Posts: 1,177
After driving for 20 minutes .

Warm idle ntc 444 - YouTube
__________________
stock 94
 
Old 09-17-2021, 06:09 AM   #13
Snedge
 
Snedge's Avatar

Name: Snedge
Title: Comp Diesel Sponsor
Status: Not Here
Join Date: Sep 2006
Location: Western Pa.
Member`s Gallery
Posts: 18,832
Well, I can't smell the smoke on YT but it sure looks like fuel. Oil pressure sounds right.
You'll want to pull the valve covers, and look for oil leaks on the internal manifold. STC issues will not cause a miss though.
 
Old 09-17-2021, 09:02 AM   #14
4x4dually
 
4x4dually's Avatar

Name: 4x4dually
Title: Moderator
Status: Not Here
Join Date: Jan 2007
Location: Stillwater, OK
Member`s Gallery
Posts: 31,789
Quote:
Originally Posted by Snedge View Post
Well, I can't smell the smoke on YT ..... incorrect.

 
Old 09-17-2021, 09:37 AM   #15
mhuggler

Name: mhuggler
Title: One piece at a time
Status: Not Here
Join Date: Sep 2007
Location: Uno, Pa.
Member`s Gallery
Posts: 1,521
Quote:
Originally Posted by jasonc View Post
I still have fond memories of the 3116 I had in a Kodiak, Not.
Was an over heating pos they never could fix under warranty, they just patched and rhode me out until it was over.
That actually had nothing to do with the engine. Chevy was too cheap to put a real fan/fan clutch in those trucks, a well known problem. The biggest issue with the 3116 is people keep trying to fix and/or maintain them themselves. There's not a whole lot you can do on those without the Cat special tooling. If you kept the rack in synch., and top end adjusted they had a nice purr.
__________________
2002 2500 4x4 ETH/DEE-F1 Mach 5's/62/65/12/Smarty/ATS Ex.manifold/AFE intake/TST Comp./.020 marine gasket/o-ringed/ARP studs/5"stacks/Airdog 150/Isspro guages/Southbend 3600 DD/3.54 gears/leveling kit/Bilstein 5100frt,5150rr/37" BFG A/T's on 18" Eagle 114's/Borgeson SS/DSS
 
Old 09-17-2021, 10:52 AM   #16
Snedge
 
Snedge's Avatar

Name: Snedge
Title: Comp Diesel Sponsor
Status: Not Here
Join Date: Sep 2006
Location: Western Pa.
Member`s Gallery
Posts: 18,832
Quote:
Originally Posted by mhuggler View Post
That actually had nothing to do with the engine. Chevy was too cheap to put a real fan/fan clutch in those trucks, a well known problem. The biggest issue with the 3116 is people keep trying to fix and/or maintain them themselves. There's not a whole lot you can do on those without the Cat special tooling. If you kept the rack in synch., and top end adjusted they had a nice purr.

Please stop bringing that Cat mouth into a vintage Cummins thread.

Next thing you'll pull Faulkner will be in here with his Cat spewing face.
 
Old 09-17-2021, 12:59 PM   #17
SCHMITTY
 
SCHMITTY's Avatar

Name: SCHMITTY
Title: Not enough time
Status: Not Here
Join Date: Jun 2012
Location: K beach, AK
Member`s Gallery
Posts: 1,177
Any recommendations for a place to send in my injectors or buy from ?
The compressor seems to be running non stop also.

The egt probe is installed after the turbo. Should I move it to the manifold ?
__________________
stock 94

Last edited by SCHMITTY; 09-17-2021 at 01:01 PM.
 
Old 09-17-2021, 01:17 PM   #18
4x4dually
 
4x4dually's Avatar

Name: 4x4dually
Title: Moderator
Status: Not Here
Join Date: Jan 2007
Location: Stillwater, OK
Member`s Gallery
Posts: 31,789
Quote:
Originally Posted by SCHMITTY View Post
Any recommendations for a place to send in my injectors or buy from ?
I wonder if Jeff Mumau could do them....
 
Old 09-17-2021, 02:09 PM   #19
Snedge
 
Snedge's Avatar

Name: Snedge
Title: Comp Diesel Sponsor
Status: Not Here
Join Date: Sep 2006
Location: Western Pa.
Member`s Gallery
Posts: 18,832
Quote:
Originally Posted by 4x4dually View Post
I wonder if Jeff Mumau could do them....
Nope. I could replace them. If you want to send them for repair, Diesel Controls in Ohio is the way to go.

The air compressor may be running all the time means you probably have a hole in the main line from the compressor to the air dryer. You'll never hear it leaking, so either spray soapy water on it while it's running, or remove the line at the compressor and put shop air into it. It'll show up then.
 
Old 09-17-2021, 02:17 PM   #20
BigPapa
 
BigPapa's Avatar

Name: BigPapa
Title: Truckless
Status: Not Here
Join Date: Jan 2008
Location: Springfield, TN
Member`s Gallery
Posts: 5,008
Quote:
Originally Posted by Snedge View Post
Next thing you'll pull Faulkner will be in here with his Cat spewing face.
Is that like a hair ball?
__________________
Scott

2003 Avalanche Z71

Common sense is like deodorant. The people that need it most never use it.
 
Closed Thread

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 10:36 AM.

 


Powered by vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2006 - 2024, CompetitionDiesel.com
all information found on this site is property of www.competitiondiesel.com